FAQ for 7xx/9xx/90 Cars
Filters. I've had one for a year and due for a replacement and "surgery"
next year. But my unit is made by Tekonsha (#4350A.) It is call "MagFilter"
and goes in the A/T return line. In addition it has a very strong magnet
ring inside, you stick a nail to the plastic cover and it will hold it.
Should be replaced every 15K to 20K mi. and it's about $28Cdn. I've been
running with this setup in -36F (-38C) no problems. It filters down to
30 microns. For more info call Tekonsha 800-325-5860 (for your local distributor)
[Note: IPD now sells this filter for both A/T and P/S line applications;
Wix sells the same unit under their label.] After I changed it I opened
the used one. I found that the magnet inside was foul with metallic particles
(it looked like grease, because the metal dust was mixed with ATF).
Return line: The top line is the return
line. You can check it by connecting a hose to the end from radiator (disconnect
the "+" wire on the ignition coil) and try to start the car, you'll see
ATF coming out of the line on radiator end. [Another note:] Hurst now makes
a filter unit that splices into the transmission fluid lines. It uses a
Fram oil filter as the filtering element.
I recently changed the trans. fluid in our '92 940 using the cooler line
disconnect technique. There are apparently a couple of variations of the
My Haynes manual outlines the following
steps (from memory, so they may not be *exactly* so, but it's close)
Here is another variant for the driveway or
garage: I followed the return line back from the trans to the radiator
and disconnected it at the radiator - it was the upper of the two lines
at the radiator. I connected a clear plastic tube to the radiator fitting
and down to a gallon milk jug marked with 1 qt marks on the sides.
I used the engine to drain out the fluid (not the starter - the fluid does
not drain out all that fast - ~25 seconds for 2 qts - and stops as soon
as the engine is shut off - so if you limit it to 2 qts at a time I'm pretty
sure you don't hurt anything). [Variation: as the jugs fill up, refill
with the quantity drained without stopping the engine.] Also, I performed
the drain - refill steps more than twice (I think I did it 5 times!) so
that by the end the fluid that was draining out was *clearly* new fluid.
(I figured that Dexron II oil is pretty cheap and a few extra quarts are
worth it to ensure that I get a proper flush - now if you want to use synthetic,
it would certainly be more expensive to do what I did.)
This technique works if your car is on a lift
Obtain a clear plastic tube (3/8 inch I.D.)
and two gallon milk jugs, calibrated with a permanent marker in quarts.
Have at least your tranny capacity (approx 9 qts.) in new fluid on hand.
Drain all the oil from the transmission drain
pan (2-3.5 qts depending on model).
Refill 2 qts into the filler tube.
Disconnect the rear transmission cooler (return)
line at the tranny and connect a clear plastic hose to the tube leading
to a gallon milk jug on the ground.
Turn on the engine. Fluid will start
draining out of the tube into the jug.
Watch the fill rate on the side of the jug
and have a friend refill at the same rate into the filler tube. [Editor's
Note: have a friend engage parking brake, apply the main brake, and place
the transmission in "drive" for a minute to flush out other parts of the
body and torque converter.]
Button things up, check final level, check
for leaks, etc.
Everything worked very well - the only
pitfall was that I ended up overfilling the trans. a bit (~3/4 qt) - I
think I must have been a little off every time I estimated I had drained
2 qts. So finally I had to pump all that out of the filler tube while checking
the level - a bit of a hassle but not too bad. [Tip: if you overfill, just
unscrew the pan bolt slightly and hold it while the fluid drips out to
the quantity required. Messy but easy.]
Fluid Needs Changing; Late or Poor Shift Quality.
[Query:] The drive gear engages
late when shifting from P to D in my auto transmission. [Response:
Marc] The problem you describe can be attributed to either a low
level of transmission fluid or a stuck valve body. If the fluid is low
in the torque converter, it will take additional time to transfer the engine
power to the transmission, as the power is transmitted through a fluid
by spinning up a plate with fins on one side and the fluid spinning up
a secondary plate with fins on the other (thus keeping fast changes in
the engine power output from damaging the transmission).
I would recommend that, if you have not
recently (within the last 6 months) changed the transmission fluid and
transmission filter, you have this done. In my area, the change runs as
low as $49.99 US, including parts & labor. If you have the Haynes manual
for your car, take it with you if go to anyone other than the dealer, as
the fluid may have to be drained in a non-standard way via a transmission
fluid cooler return pipe (non-standard compared to other brands of vehicle).
This service will also clear up most sticky valve bodies, as the new fluid
reliquifies old gummy deposits...[Editor's note: see also Fluid
[Symptoms:] Late or poor shift quality.
[Response 1:] Since this is an unknown as to when the transmission
was serviced I would recommend a power flush. Wynn's/Kendall has a machine
that connects to the line to the cooler. Then they add a detergent and
run the car for about 20 minutes with it off the floor and in different
gears. Then they go from a recirculation mode to a change mode and add
new fluid while discarding the old. This gives a full change including
the torque converter. It will cost from $60 to $95 but I think it is well
worth it about every 100000 miles with normal change in between. I think
both my ZF and AW worked better and smoother afterwards. Call around
and you should be able to find some shop that does a power flush.
[Response 2:] How dirty was the fluid
was when the transmission was finally serviced? Your transmission has no
bands, just clutches. When pressures are right for a shift, fluid pressure
is directed to the clutch(es) that is/are to lock up. If there is a lot
of clearance due to wear in the clutch packs, you usually get a delayed
and hard shift. If the valve body has a problem, it could cause reduced
pressure to go to the clutch pack, causing a slip as it shifts. The
most common problem is governor pressure loss due to a worn output shaft
bearing. Even after the output shaft bushing is replaced, the problem could
still exist because while the bushing was bad, excessive wear to the transmission
case where the shaft goes through, is common. A pressure test will in most
cases will pinpoint the problem. This is reason # 71 for servicing the
transmission at normal intervals. Every 20,000 miles is recommended. It's
pressure test time.
Transmission Fluid Drain. [Procedure:] ZF 4HP22 Transmission Fluid
Change. This is passed along for the 740 owners with this transmission.
I have the same transmission on my Peugeot and found out that if you leave
the car for a few days on with the front end on jack stands, the fluid
in the converter will slowly drip out. This way you can get an almost complete
drain before refilling. [Maintenance Note:] There also seems to be a consensus
by mechanics who work on this transmission that there is no advantage to
using synthetic AT fluid (this question asked relative to the early failure
problems from revving the engine with transmission in neutral). [Contrary
Opinion:] I agree there is a problem with those trannies. You should know
one more thing, HEAT is the biggest enemy of every tranny (especially in
automatics). I've got one on my 740 and synthetic ATF dropped the tranny
temperature from 92C to 60C (driving in a summer for about 40min. in a
city). I've measured the temp. on the tranny metal line, the temp. of the
fluid itself is most likely higher.
Repair. My wife got excited by our new (old) 1988 745T, and managed
to yank the gear shift knob clear off the shaft, with the OD switch wires
dangling. The switch pushes out fairly easily and r&r was no problem;
the wiring is a little tricky since it tends to jam (at least on mine)
and make it difficult to properly seat the gear knob. I used electrical
tape with a spot of grease smeared on the outside (I know, it's a solvent,
but it prevents the wires from jamming), and the knob simply squeezed back
[See Relay Locations
for a detailed picture of relay location and removal instructions.]
[Symptom:]I have a friend with a '90 740 automatic and he is having intermittent
OD problems that seem to be weather related. It won't go into OD when the
weather is cold. Is the relay on the relay tray? If so, which one is it?
[Diagnosis:] Yes it does sound like an OD relay. If I remember correctly
on 740 it is by the Ashtray/FuseBox. It is pretty common component failure
on the bricks. It will be a white Hella relay. Pretty simple to change.
The relay is about $40-43 through Mail order from dealership. In my case
I was "sure" it was the wiring, switch or solenoid, as the relay "looked"
just fine. But as soon as I replaced the relay, all problems disappeared.
The relay is about $40 from the dealer, or you can probably find it cheaper
from a second source...it appears to be a standard Hella relay.
[Response 2: Michael Daley] I have
just repaired the o/drive relay and rather than pay the UK£40 that
the volvo dealer wanted for a new one, I took the top off the relay - all
that was wrong with it was a cracked solder on the circuit board. Fixed
with a soldering iron in 5 minutes, saving myself £40!!
For a more detailed discussion of relay
repair, see Relay
Repair vs. Replacement.
[Another OD Symptom:] I have a '93 940T
with an AW71L transmission (or so I've been told...) Today I was driving
on the highway and it momentarily dropped out of overdrive into 3rd,
at the time I was at minimal throttle. I dismissed that as a hiccup. An
hour later (after making a couple of stops)I began driving and I noticed
that the tranny would not go into OD, 3rd gear was the max. All of the
other shifts are perfect. I tried pressing the OD cancel button a few times,
and I checked the related fuses - no changes. Am I looking at replacing
the overdrive solenoid on the tranny? If so, can anyone give me a part#
and/or approx. price? [Response: Abe Crombie] It is an AW71 no L.
The turbos didn't get the locking torque converter feature. The trouble
sounds like the typical OD relay failure. The relay is behind the ashtray
in the fuse/relay panel. I believe it is white on that car and square in
profile. The fuel system relay is the one to the left that is rectangular.
Trans Overdrive Problems: Solenoid. [Diagnosis: S. SteveSakiyama]
There have been a few posts on autotrans overdrive problems (won't shift
into 4th) when the brick is cold. The problem disappears when the
car warms up. I posted my experience a month ago in response to another
member who was having the same difficulty. I'll repeat a summarized
This applies to automatics, don't know
about manuals. I have an AW71 in my 85, 245 Ti. When cold it
would not go into 4th (OD) until the car had been driven for 10 minutes.
This would happen more and more frequently until it was a regular pattern.
Sick gut feelings (is a major repair needed?) usually accompanied this
problem. I checked/dealt with fluids, OD relay, wiring, and downshift
cable but the ultimate problem was overdrive solenoid switch which sits
on the tranny. I bench tested it, and it seemed fine. However
an experienced tranny tech said "it just doesn't sound and feel right".
Replaced it with a used one (with the two inner o-rings), and the brick
Overdrive Malfunction: Fluid Blockage. [Query:] I hope
to find someone who understands the inner workings of the AW71 auto transmission.
About a month ago, mine stopped shifting into 4th (overdrive). Once in
a while it still works when fully warmed up but not always. I've replaced
the OD relay with a new one but no change. I then pulled the OD solenoid
which appears to be closed when not energized. I replaced the O-rings and
reinstalled but no change. Before I buy a new solenoid, I would like to
ask the following questions:
1) Is the OD solenoid
involved in the normal operation of the trans or does it merely allow the
disabling of fourth gear via the switch on the shifter?
2) When operating normally
(OD not disabled) does fluid flow through the OD solenoid or is it blocked?
3) When the solenoid
is not energized, is it open (to fluid flow) or is it closed?
4) Other than the OD
solenoid, what could be causing my problem?
By the way, it's got 147K miles on the
[Response 1: Scott] My first guess is
the OD solenoid. The solenoid is naturally closed cutting off the fluid
flow necessary for 4th gear. When energized OD on/light out the solenoid
opens up and allows the trans to shift into 4th. The first test is to park
in a quiet place open the drivers door and switch the OD on and off while
listening for a click under the car. If you don't here it it is bad. If
you do hear a click that does not necessarily mean it is good. Also check
the wiring under the car to the solenoid. It tends to deteriorate near
the shifter. [Response 2: Brian Oliver] I learned about the
inner workings of the AW71 when we had this problem on our 87 740. It smelled
too much like a control problem so I messed with the downshift cable (no
effect), had the OD solenoid wiring checked (100%, oddly, as this is the
typical culprit) and even took the car to a transmission shop, who suggested
a valve body overhaul. New fluid and diddling the level had no effect.
Finally my wise old Volvo mechanic suggested
that the plumbing internal to the solenoid unit, which has a right angle
turn at the valve seat, could be plugging up. Problem: On my car the bolts
may have been seized, and if one breaks then the transmission has to come
off just to drill out the broken bolt. I took the chance, and half an hour
later the solenoid unit was off, blown clear with compressed air (energized,
I think, to open the passage) and reinstalled. The transmission worked
Output Shaft Bushing. Why Replace the Seal and Bushing?
...we replaced ours ('89 745) a few months
ago, at approx. 115,000 miles. Why? I noticed that the output shaft was
spraying a bit of oil onto the underside of the car... and my experience
teaches me that such leaks only get worse, plus tailshaft play accelerates
Let me say that this is not necessarily
bad or that you don't have an output bushing worn and a seal leak. First,
when the bushing's worn, you usually get some driveshaft vibration, or"humming/drumming"
in the car. So when the new bushing's in, it's noticeably quieter. (That
was my experience on my '83 and '86 GL's, both receiving the bushing &
seal at around 200k.) Second, if the machined outer surface of the
companion flange is worn where the seal rubs, there's a possibility of
driving the seal 1/8" further into the housing so the new seal "sees" a
fresh, non-worn surface. It all depends on how the original was mounted.
You should try shaking the driveshaft radially at the transmission and
see if there is any lateral movement...if you're unsure try shaking a known
good one. Also, you can replace the seal yourself and leave the bushing
alone...it will seal for awhile, perhaps a LONG while. Last point ...when
replacing seals like these, check the metal part that the seal rubs against...if
there is a notch you can catch your fingernail on you probably need to
replace the metal part too...a rear axle pinion flange is easy but a driveshaft
yoke you have to replace a U-joint, etc. (some people think U-joints are
This is part of what I'd refer to as preventative
maintenance. I was quoted a price of $300-$350 to replace the seal/bushing.
Bought the parts for about $45 (parts replaced were output shaft bushing,
output shaft seal, rear housing gasket) and performed this operation myself
in about 3 hrs, including setup/replace/cleanup time. Pulling the housing
is relatively straightforward once the tranny's supported and the cross
member and mount are removed. I believe that there are six bolts to remove
and the housing's in your hand. Have a new gasket on hand and make sure
that both mating surfaces are completely clean with no trace of the old
gasket. You don't want to have to do this job a second time because of
[Another tale:] The tail housing removal
is really pretty simple. I just finished replacing a transmission in my
'89 744 project car. The tail housing was cracked and we initially hoped
to replace only the housing, but Volvo wanted $253 for it and the junkyard
had an entire AW70 for $400. Anyway the Dexron is still in my hair from
finishing up the job, so my experience is as fresh as it gets.
What you're going to do is take out the
bolts that connect the output flange to the driveshaft, support the tranny
and remove the rear transmission mounting bracket. Four bolts hold the
tail housing to the rest of the transmission case.
[Procedure Notes 1:]
Start with the driveshaft bolts while
the car is still on the ground. That way you can roll the car a little
to get to all 4 bolts *easily*. If you're driving up on ramps like I did,
this won't work and you'll need a crow's-foot wrench (my 9/16" worked fine)
to get to the ones on the top of the flange. A generous supply of profanity
helped in my case... It's a good idea to mark the output flange and shaft
flange so you can mate them up when the time comes to put it back together
[critical for proper driveshaft balance.] Once the bolts are out, push
the driveshaft toward the rear of the car and it will pop out of the flange.
You can shove it up above the flange to get it out of the way. Raise the
car up (jackstands, ramps whatever)if it's not already and drain the tranny
fluid. Put the selector in Park and use a socket to remove the bolt in
the center of the flange. This bolt holds the flange to the output shaft.
Once it's out you can pull the flange out of the housing. Remove the 15mm
nut in the middle of the transmission mount (rear end of transmission).
Support the case with a floor jack, just enough to take the pressure off
the tranny mount. You should see the mount bolt come up slightly. Then
remove the four bolts that hold the mount to the chassis. The mount will
come off, and the tail housing will be clearly visible. Four bolts (14mm
I think) hold the housing to the main body of the tranny. The top and bottom
bolts are different lengths, so note where they came from. With a little
"gentle persuasion," the housing will come off. On my particular car, the
PO slid it into a ditch and caught the end of the center mount bolt which
cracked the housing. This also saved me the trouble of taking off the "L"
mounting bracket. It won't have to come off if you just plan to replace
the seal. The seal is easy to get to and *looks* like you could pry it
out with a screwdriver, but I have never tried this. You're going to end
up with a roughly 6x6x8 inch housing which you can work on at your leisure.
If you don`t have the tools to remove/replace the bushing, you can just
bring the housing to almost any auto service shop and they will be able
to press a new one in for a few bucks. Plan for about 2 hours under
the car to get it out. If the gods of rusted bolts are on your side, it
could be done in 45 minutes or so, I'd guess. Nothing is particularly difficult
about the operation. Although I recently told someone to shoot me if I
ever said it, "installation is the reverse of removal" (BOOM). See orientation
notes below. The center flange bolt only holds the flange to the
shaft; no pre-tensioning or any of that other technical stuff.
[Procedural Notes from Bill Lauber:]
AW70 REAR BUSHING REPLACEMENT
Regarding Volvo Automatic transmission
AW70 rear bushing replacement ...I found significant play in the
end shaft and proceeded to get the parts from my local Volvo dealer.
The bushing was quoted at $36 with the seal at $11 and the gasket for about
$5. I checked the yellow pages for a automatic transmission parts
house .. found one and learned the following. They carried every
thing I needed, the only difference being I carried the parts out for a
total including tax of $9.70. A entire rebuild kit for the Volvo
automatic was quoted at $108.00 and the dealer said the Volvo AW70 was
one rebuild an individual could be successful with. I have installed
the bushing, seal and gasket and all is working well.
I used drive on ramps at the rear wheels
not the front. This keeps excessive loss of ATF fluid when removing the
rear housing. HINT, with front wheels blocked from rolling, elevate
one side of the rear all to allow rear wheel to spin on one side. This
allow all to spin for easy access to drive shaft bolts as long as the transmission
is in neutral and the emergency brake is off.
Place support under Transmission pan that
can be raised and lowered as needed A board between the support and
pan will help distribute the weight normally handled by the rear transmission
support which has to be removed.
Remove rear transmission support bolts from
car frame and end of transmission and remove cross member
Disconnect speedometer hold down bolt at transmission
then unscrew cable from transmission
With transmission in neutral, disconnect end
of drive shaft from transmission
Insure transmission is in park
Remove transmission shifter link’s rear pin
ONLY allowing link to move out of the way
Remove bolt from rear of shaft on transmission.
Remember step 5 ... pull out shaft end
Remove all 6 bolts holding rear housing
Remove housing HERE COMES THE ATF!!... you
may have to tap with block of wood to break loose from gasket. be gentle
so not to crack the housing
HARDEST STEP for me ... remove the old gasket
material [Editor's Note: See Removing the
Punch out the old seal and bushing ... the
seal was easy ... the bushing requires care not to crack the housing. You
may want to have a machine shop remove and replace the bushing. I was successful
but could just as well messed up at this point
Install seal & bushing in housing [Editor's
Note: See Bushing
Install housing with new gasket and six bolts
Insert shaft with some ATF on bearing, seal
and shaft Torque shaft bolt
Hook up shift linkage
Shift to transmission to neutral
Install drive shaft and bolts spinning elevated
rear wheel for easy bolt replacement
Install speedometer cable
Install cross member ... elevate transmission
After removing car from ramps check ATF and
add as needed.
[Another Procedural Note from Don
The parts you'll need are: new bushing;
new seal; new gasket. In general, the procedure is:
the Gasket: Randy] I've replaced two bushings and both times the most
time consuming part of the job is removing the gasket between the transmission
case and the rear housing from the transmission case. There isn't a lot
of room to work your way around with the various tools to scrape the gasket
off. I found a single edge razor blade worked best for me, and the second
time I did it I was armed with a spray on gasket remover which helped a
whole lot. Spray it on, let it soak, scrape a little.... repeat numerous
times, being careful not to dig into the soft aluminum case when you become
frustrated and begin to use that sharp wood chisel that always worked so
well on removing gaskets from cast iron casings. Also it would probably
be in your best interest to take extra pains to protect the exposed portion
of the transmission from consuming the gasket pieces and various bits of
underbody debris you will rub off with your arm- I wrapped mine in a clean
rag (the rear of the transmission, not my arm)
Jack up the car -- from the rear may be preferable.
[Editor's note: mark the flange and shaft
for proper balanced re-assembly.Carefully mark the linkage placement before
removing it from the side of the tailshaft housing.] Drop the driveshaft
at the tranny -- I don't think it needs to be removed any further, only
Remove the companion flange -- I used an air
gun (with the tranny in park). Some purists among us will probably tell
me how wrong that is -- but both cars logged at least 50k flawless miles
Drop the crossmember -- you might want to
support the tranny.
Remove the speedo cable.
Position a pan under the rear of the tranny
-- some fluid might decide to get in your face. Transmission fluid will
run out when you remove the piece the driveshaft was bolted to (flange?)
as well as when you loosen the tailshaft housing so be prepared with a
pan to catch it.
I think you need to remove the tranny mount
bracket from the housing to gain access to the
Unbolt the housing from the tranny. Pull back
gently -- a little tapping may be helpful.
Knock the old seal out of the housing.
Note the orientation of the old bushing as
a reference for installing the new bushing.
Examine the inside of the housing -- note
there is a 1/4" gap, or opening, under the bushing, at the bottom of the
housing into which you can cut.
Using a hacksaw blade, cut through the old
bushing into this opening. Note the orientation of the original and
align the new bushing the same way.
"Peel" the old bushing inward and it'll pull
Scrape off any gasket material (most frustrating
part of the job.) [Editor's Note: See Removing
Wash the housing, insuring that all chips
are removed. [See Chip Removal]
Be sure to prelube the new bushing and new
seal before final assembly. Position and orient the new bushing --
and using either a proper bushing/seal driver OR a socket of the correct
diameter (perhaps with a 6" extension on it), drive the new bushing into
position. I've found it slides into position easily, with only slight tapping
from a hammer. [See Bushing
Orientation] [Tip from Randy:] My automotive supply store
has a full service machine shop and I never mess with this stuff- I take
the tailshaft to them and have them press in the bushing. For the seal
I apply a coating of grease to the outside diameter and tap it into place
with a socket just slightly smaller than the diameter of the seal.
Examine the new bushing to confirm the edge
was not dented -- if so, clean it up slightly with a fine rat-tail file
(and rewash). Be careful to not damage the main bearing surface of the
Drive the new seal into position. I like to
use a touch of Permatex aircraft gasket sealer, but it's not necessary.
Clean any remaining gasket from the mating
Install the new gasket. Again, I like to use
a touch of gasket sealer, but it's not required.
Lubricate the bushing and seal with ATF.
Position, install, and tighten the housing.
Wash the rear flange, lubricate the bearing
and seal surface, and slide it over the splined tailshaft.
Install and tighten the nut. I'm sure there
is a proper procedure and torque.
Install the speedo cable.
Lift the tranny and install the mount bracket
and crossmember. This might be a good time to install a new mount.
Connect the driveshaft. [Editor's Note: 30
[Tip from Randy:] On assembly be sure
to bolt the linkages according to the marks you made before disassembly.
Don't forget to check the transmission fluid
level, particularly if you lost some during this work.
Paul Seminara] Replace the bushing, when you do the rear seal.
Indeed the bushing will wear and sometimes the wear will be from small
bits that wear the tailshaft flange as well. This is especially so on high
milers. This usually will require replacement as well.
Auto Trans Output Bushing Orientation Question. [Query:]
In replacing the auto trans output bushing, which way does the hole in
the bushing go? [Response: Patrick Petrella] I did get the bearing
issue resolved. Ended up talking with a mechanic in Colorado, who seemed
to know what he was talking about. Volvo was essentially no help. Someone
sent me jpegs of two pages out of the Volvo trans shop manual, which clearly
stated that the new bearings come with no hole in the side. I went back
to the parts counter at Volvo and was shown that all their bearings HAD
the side hole. A never-ending spiral of confusion. So this Colorado
mechanic said he had done this repair on many AW71 trans, and that the
orientation of the side hole was not critical, but should NOT be lined
up with either slot in the tailshaft housing. He puts the sleeve bearing
in with the hole at the top. So that's what I did. I would like to know
what the hole is for. Maybe used during manufacture of the bearing, with
nothing to do with operation?
Hard Shifts. [Great Tip from Toni Arte] The AW71
in my '86 740 used to shift very hard from 1st to 2nd gear. This shift
is the first shift and it usually happens at about 20 km/h (depends on
how hard you accelerate). It felt almost like getting rear-ended.
Nothing really helped. I tried to adjust the kick-down cable, change the
fluid etc. Then I heard that this is a common problem on AW70 series transmission.
The real cause for this problem is a worn
valve ball in the transmission valve body. This ball is the "15C" in the
picture. This is a picture of the lower valve body. A replacement valve
ball is available, you can order it from your local Volvo dealer. The part
number is 1377746-1 (small blue valve ball).
In my case the 5.5 mm valve ball was worn
to about 2 mm size. Note that the valve body can be accessed through the
oil pan, so it's not necessary to drop the transmission. A competent
transmission shop should be able to change this ball. In my case the cost
was about $100, this includes two hours of labour, new gaskets and fluid.
[Tip from Gary De Francesco] Rough
1 - 2 shifts are a possible sign of a worn rubber ball in the valve body
that regulates how fast the various clutches and brakes are applied. As
the ball wears, the fluid flow rates in some of these regulating passages
can increase which will cause the various hydraulic actuators to engage
faster. This will feel like a sudden and rough engagement. On the
one hand, with fast engagement, there is little chance for the clutches
and brakes to slip. This means less wear, and hence a longer lasting tranny.
On the other hand, these fast engagements result in a bit of jarring to
the occupants of the car. The solution is to have the valve body serviced.
This can usually be done without removing the tranny. So you have to decide.
Can you live with a little jarring, or do you want to spend some money
and see if it can be smoothed out.
Upshift. [Symptom:] If I accelerate very hard, I lose top gear, and
as I slow down I lose each consecutive gear. I then have to almost redline
the car before the transmission will upshift. [Fix:] The symptoms sound
suspiciously like the transmission downshift cable is binding. It is not
that uncommon on higher mileage AW70/71 transmissions. Oft times the binding
is temperature dependent... The cable allows the valving within the automatic
transmission to "know" the current throttle setting. It runs from the passenger
side of the transmission up to the throttle "bobbin" on the engine (drivers
side). The return spring is internal to the transmission and the cable
is pulled out as the throttle is opened. If the cable binds, it will remain
limp at part throttle... giving an incorrect signal to the transmission
and making for prolonged operation in the lower gears. The cable is not
all that expensive - approximately $75, and the labor charge is likely
to be under 3 hours book time (FWIW, the first time I changed the cable
myself it took 1.75 hours start to finish).
Function of Kickdown Cable.
[Discussion from Abe Crombie] The kickdown cable is used to regulate a
pressure in the transmission valve body. This is called throttle pressure.
The throttle pressure is effectively a pressure that "tells" shift valves
in transmission how hard you are pushing the throttle and these shift valves
now have a contest to see if governor pressure or throttle pressure is
going to win. This pressure is also used to apply the clutches/brakes that
engage a gear and the higher pressure goes along with higher engine power
at higher throttle. Firmer shifts are a result of higher throttle pressure.
If throttle pressure wins the contest the trans remains in lower gear,
if governor pressure wins the trans upshifts. Governor pressure is
directly related to driveshaft, and thus road speed. If you tighten
cable you increase throttle pressure and the whole shift point/road speed
"map" goes higher. If you loosen cable the shift point map moves
lower. The trans throttle cable (kickdown cable) also depresses
a valve if you (or the throttle spool) pull the cable all the way out past
that hard spot which is a detent to make you aware of the actual kickdown
feature. The kickdown valve increases the throttle pressure drastically
above the linear rate that you get from the rest of the throttle pedal
travel range and makes the gearbox goes to lowest possible gear allowed
at the road speed you are at when you activate it.
Adjustment of Cable. The kickdown
cable has no adjustment at the transmission end, it's fixed. All the adjustment
is under the hood, at the throttle spindle. To adjust, loosen the cable
housing jam nuts until there's plenty of slack in the cable. Pull on the
cable, then let it snap back in. Listen carefully, and you'll hear the
cam that the cable is attached to in the automatic transmission click up
against its stop. Try this a few times, so you'll know the sound. Now adjust
slack out of the cable, keep testing by pulling and letting go of the cable,
always listening for the click inside the transmission. As you take more
and more slack out, there will be a point where you've tightened the cable
just enough so the cam inside the transmission can no longer click up against
the stop, because the tightened cable won't let the cam go back far enough.
When you reach this point where you just stop hearing the cam click against
its stop, the cable is adjusted properly.
Cable Replacement. [Symptom: I just found out the kickdown cable on
my 88 240 [Note: same on 7xx/9xx] won't retract. I'm inclined to fix it
my self but don't know what cause it and how difficult to fix it. [Repair
Procedure:] Parts are about $100 - $75 for the kickdown cable, $25 for
tranny pan gasket and filter. It's about an 1-1/2 hour job, very messy
though as you must drop the tranny pan. You kind of need an assistant to
help with the cable, and a long pair of narrow vise-grip pliers. Basically
[More Tips from Don Foster] Replacing the
cable is straightforward. If you have the pan already off,
swapping in a new cable should take only a few minutes. Look
in where the cable attaches, and you'll see a cam-like or pulley-like gizmo
around which the cable wraps. You can (carefully) turn this with a sharp
tool or screwdriver (it's spring loaded.) You'll be rotating it against
it's return spring, and as I recall it's a little tricky. Once rotated
to the fully extended "full throttle" position, stick a screwdriver in
to wedge it and you should be able to pull the cable end free of its hole.
The old cable will disengage -- it has a round thingy at the end fitting
into a recess.
Drain the transmission of fluid.
Unbolt the dipstick/filler tube from the transmission
sump (may be "very" difficult and require a giant pipe wrench). More fluid
will run out.
Unbolt and remove transmission pan. More fluid
will run out.
Unbolt and remove the transmission filter.
More fluid will run out. You now have access to the cable and tranny innards.
Have somebody fully extend the cable, this
will rotate the internal valving fully. Clamp onto the rotating valve (where
the cable attaches) with the narrow vise grips immobilizing the valving
(it is spring loaded). With a second set of narrow pliers remove the cable
end from its recess in the valve actuator. [Tip from Ian Billerwell]
I recently replaced cable on my 89 745 with AW72L and found a handy tool
to rotate the pulley. A bit of coathanger wire 6 to 8"long with 90 deg.
bend only 1/4". In my pulley there is hole in the side near where the cable
locates, I found it a cinch to rotate pulley.
Remove the cable & sheath - friction fit
in transmission, bolt-on at throttle body.
Re-assembly is reverse of disassembly. Careful
to remove the vise grips until the new cable sheath is seated in the tranny
and the cable end is attached to valving.
The tranny end of the cable housing friction-fits
into the tranny housing. I'd clean and blow-dry the outside area before
removing the old cable. As I recall, you can "pop" if out with a screwdriver
-- and "pop" the new one in similarly. I used a touch of synthetic grease
on the O-ring-like seal.
Once installed, you install the upper
end and adjust it so it just slackens when the throttle's at idle. Also,
you should be able to hear the tranny valve "clunk" slightly when it slams
back to idle. Install the small crimp around the cable core about 1/8"
upstream of the orange rubber gasket. This crimp is sorta important
-- it prevents excess cable from entering the tranny and keeps the cable
in the pulley groove.
Not Shifting Out of Park
My transmission will not shift out of park when I step on the brake.
[Response: Bob] Shift lock solenoid not releasing. Possible causes, brake
light switch, micro switch in shifter assembly. Micro switch most
common. Access shifter by removing cover, on passenger side near indicator
is a small black switch with a metal lever. Switch about 1 in. long @1/2
in wide, mounted with a small round metal clip. There are two black
wires. You have to unbolt the shifter and lift up slightly to access switch,
but don't have to disconnect anything under car. Be careful removing switch
retainer as its easy to break the small plastic post the switch mounts
to. To test, short the two wires together with key on and brake pedal pressed.
If it now comes out of park, replace or bypass the switch.
Shift Lock Switch Replacement.
[Tips from Tom Irwin] Lately, my AT has been failing to allow a shift out
of "PARK" about 90% of the time. I have to press the Shiftlock override
to get going. This car was serviced in 1996 under the recall
campaign to replace a defective shiftlock microswitch inside the shifter
console. The "A-hah!" went off in my head because I have been substantially
underwhelmed about the abilities of the dealership where I purchased the
I got out the books and went looking for
trouble. To get at this thing, it is advisible to remove the following
parts, roughly in this order:
Both Right and left knee bolster covers.
Two screws on the left and one on the right cleverly concealed behind a
snap lock cover. Un-buckle and un-snap them the rest of the way. NOTE how
they slide out of a plastic extruded support molded in to the kick panels.
Dum-Dum's at Volvo dealer had jammed them back in, over and under these
supports and tweaked them all to hell. It took awhile to get 'em back in
right. Had to let them bake in the sun for a while to get a little pliable.
Take out the ashtray in the front and
Pull up on your E-Brake. Slip a finger
under the screw concealment panel and wiggle it side to side till it pops
Remove two screws that secure left and
right side of center console to the transmission tunnel.
Remove the two screws holding your armrest/cupholder
to the junk box. NOTE: If you have ever dropped that armrest or otherwise
treated it rough, you will see cracks in the hinge guides that support
your release latch on the armrest/cupholder/junk box cover. Now is an excellent
time to put a small drop of super glue (NOT the gel stuff) right there.
It will wick in to the cracks and reinforce them.
Empty ALL your junk out of the junk box.
Use a small slotted screwdriver to lift out the screw concealment panel
in the bottom of the junk box. It is tough to see, use a flashlight.
Remove two screws from the bottom of the junk box.
Lift up whole center console assembly
from the rear, a few inches. Put two fingers under the wood-look
trim around the rear seat ashtray bezel. Push up on two tabs and
lift ashtray bezel up and away.
NOTE: The little light bulb that is supposed
to light up your rear seat area and the inside of your junk box usually
is dead, now is a great time to replace it.
Lift whole center console up and away
and remove it from the car. NOTE: This too is a good time to scrub
down the plastic mold of the center console, scrape off old food, spilled
drinks, whatever. You will no doubt find a couple of dollars down there
between the seats. Now you can vacuum out the seat tracks where heretofore
you could not get down there with the skinniest of attachments.
Disconnect the wiring harness that goes
to the shifter, (960 Left side, 940 right) Re-route the harness end
around so you have enough slack to raise the shifter a bit.
Remove 4-10mm bolts that secure shifter.
Raise shifter up an inch or two. Lift up the dust flap on left
side of shifter.
There it is, a snap-acting microswitch.
If you are in "PARK", it should be pushed down. It mounts on
two plastic pins extrusions from the shifter body. Two spring type retainers
are supposed to be pushed on to the pins after switch is installed over
them. In my case, one spring lock retainer had fallen off of the
pin and was laying in the soundproofing insulation, the other one was working
loose from the other pin.
I took off the switch, cleaned it adjusted
the lever, and tested it. Then I reinstalled it and pushed the lock retainers
on really tight.
Put everything back in reverse order and
it works every time now.
Shifter is Loose. [Symptom:] The shifter on my 745GLE (automatic) is
really loose. When I put it in park, I heard a metallic clunking. I can
move the shifter about a half inch at the top forward and back (no side
to side movement) when it is in any position. [Another Symptom on an AW:]
Last week I noticed I has having to over shift my '89 700's AW to get the
car to go in gear. In general the shift lever was quite sloppy.
[Diagnosis:] There are bushings that fit
in the ends of the shift linkage rod and when these are shot, the shifter
is pretty much adrift. They have to be among the cheapest parts available
from Volvo, and replacing them makes a world of difference. Be sure not
to lose the clips that hold the linkage together and for heaven's sake,
don't take the whole thing down - do one end at a time and save your self
the grief of not being able to remember which way it went.
[Repair Tip from Don Willson:] Saturday
I put it up on the jack stands and looked at the linkage. There were 4
places where a pin (about 1/4 inch diameter) goes thru a hole (about 1/2
inch dia) and is held on by a snap ring and washer. In every case a rubber
bushing that was supposed to be there was gone. So I replaced all four
and it surely made a difference in the shifting, now when I move the lever
to D it goes into drive.
If this fits you you need 1 #1220141,
and 3 #381704. These look to be a silicone rubber rather than the old black
stuff. It took about an hour. You can remove all 4 starting from the easiest
to get to and working up and forward. Replace them in the opposite order.
The parts are about $2.50 each so it is not a budget breaker.
Shifter Moves. [Query]
I have a 1990 740 Sedan Turbo. When I drive the vehicle and apply the brakes
the automatic transmission shift lever and gear position indicator (P,
R, N D, 2, L) moves! Any ideas on what causes this? [Response:
Bob] The shifter is conected to the transmission by two rods. One
rod actuates the shift lever on the transmission; the other rod is called
a reaction rod and connects the shifter to the transmission case. If you
remove the reaction rod from the case, the shifter and indicator will move
back and forth. With every thing hooked up and adjusted properly, the shifter
will move some when stopping, starting, shifting from R to D, etc.
It is DESIGNED to move with drive train movements. This prevents the need
for occasional linkage adjustments. If it moves a lot, check engine and
transmission mounts. But some movement is normal. [Editor: see above notes
on shifter rod bushings.]
Tranny Refuses to Reverse: Bad Mounting. [Query:] My 87 764 Turbo
has 124K miles and the AW 71 transmission has been serviced every 25-30K
miles. Recently it has started to "refuse" to go into "R" gear after 10-15
miles of operation in "D". The selector seems to operate normally with
all the usual detents, but the transmission is still in pseudo-"D" when
the selector is in "R" as the car will creep forward. Putting the selector
into "P" results in a slight lurch forward and then the transmission is
properly locked in "P". [Response 1: Rick] Sounds like
the linkage is miss-aligned. That is, your gear lever isn't aligned to
the gears positions on the transmission. [Response 2: Michael
Jue ] It could be something more (read: internal) but I'd concur
with Rick on this being the first course of inspection. Something else
you should seriously consider...especially if the shifter is maladjusted
as above: the rear transmission mount. I'd been having a number of small
niggly shifter issues in which the shifter "felt" right but the indicator
never showed in the clear windows at the base of the shifter. Then, finally
the neutral safety switch failed to work. Diagnosis: bad transmission
mount. Sheared the rubber mount from the metal surrounds. Easy fix. (Jack
up, support tranny, unbolt crossmember, remove old/install new mount. Replacement
the opposite of removal.) Who'da believed it? I've never had
a broken trans mount before. All symptoms disappeared.
Transmission Life. [Query:] Any thoughts out there on the life
expectancy of an AW70 tranny. I've got a 745 with 145K and it seems strong.
I flush the fluid every summer. I know some think this is not good, but
it seems to work. Are the AW70's rebuildable or do you just replace them?
[Response 1:] I had a minor problem with this tranny (worn check valve
in the valve body, which caused it to shift hard between 1st and
2nd gear). When it was fixed, I also asked about the tranny in general,
and I was told that these units usually require a rebuild at about 350
000 kilometers, or more than 200 000 miles. And only the clutch and brake
packs need to be replaced, usually all the bearings are still OK.
[Response 2:] They can go 250 K. They can be rebuilt, that box is shared
with several Toyota rear drive 4 cyl models in the early to late 80's.
Maintenance: Bands?. [Query:] I recently acquired a Volvo with
an AW-70 in good condition from my brother-in-law. I am planning to flush
the ATF and replace the filter in the near future. My friend suggested
adjusting the bands while I have pan off. Is this a reasonable thing to
do? Does the AW70 even have adjustable bands? The Haynes manuals are silent
on the subject. [Response: Abe Crombie] The AW55/70/71/72 and BW55
don't have bands. These gearboxes use friction discs as brakes. Disc
brakes don't require (nor is there any way for) adjustment.
Leakage in AW70L Transmission. [Query:] Oil is leaking from my
AW70L transmission at the shift linkage shaft on the right side of the
tranny housing. Does anybody know how it is to replace the seal(s)l ?
[Response:] That shaft goes through the tranny from one side to the other,
with a seal on each side. On my '83, the seal had simply popped out of
the transmission housing, and only had to be gentle pushed back in. The
bad news is that -- at least in my experience -- access to the seal is
restricted by the exhaust pipe. Dropping the pipe first made it much easier.
One thing I'd advise is to first clean up that area of the transmission,
particularly if it's been leaking for awhile. A lot of dirt and grime will
accumulate -- and you want the area as clean as possible before installing
a new seal. I washed it down with parts cleaner, hit it with compressed
air, and let it dry.
Trans Drain Plug. [Query:] Did a routine fluid change. Detected
a slow leak from the plug area a few days later. Removed plug. Threads
were stripped. Purchased new plug. Unable to get a tight fit since threads
in pan probably also be damaged. No leakage yet, but I fear that plug may
eventually loosen, I'll lose fluid and destroy the tranny. (so much for
preventative maintenance.) Replacing the fluid pan seems to be the
obvious solution. I would appreciate any suggestions on a good source for
a pan, or alternative solutions to the problem. [Response:
Simon Eng] No need to replace the pan. There is available a kit specially
designed for this purpose. My mechanic has several sets and he let me borrowed
one of the sets. First check what size is the plug. Let say it is
12 mm by 1.5 mm. The kit for this size has a drill bit and a tap with 14
mm by 1.5 mm. You drill the drain hole with this drill bit, then thread
the hole with the tap. There is an insert that has 14 mm by 1.5 mm on the
outside and 12 mm by 1.5 on the inside. Screw this insert intp the hole
and use the supplied expander to expand the insert and to position it on
the threaded hole. Now the insert is firmly anchored. If the old drain
plug is still in good shape, reuse it; otherwise get a new plug.
[Response 2: Kane] Naturally, in upsizing the plug, you'll need to
tap new threads for the hole too. Drill the hole smooth, then tap - you
don't want the new threads crossing the old ones. You may also try
"chasing" the existing hole with the exact tap size and thread count as
the current plug. Sometimes this is all that's necessary to clean the remnants
of the old plug and whatever else is stuck in the threads. This assuming
that you do have a tap and die set. Otherwise, plucking a pan from the
junkyard may be the best bet.
Line Crack Prevention. [Tip from Tony P] My lines actually
rubbed together long enough to cause a leak. I removed the clips and installed
a compression fitting to repair the leak. Then I cut some sections of rubber
hose, slicing them lengthwise so that I could slip them over the transmission
line. Then, using a zip tie or tie wraps as they are called, I secured
the rubber hose around the transmission lines to stop chaffing.
Lockup Torque Converter Function. [Query:] My 1989 745T with
AW71 has a lock up torque converter that is locking and unlocking too much.
At some speeds and loads and boost levels, it constantly locks and unlocks
until I either back off or speed up. [Response: Abe Crombie] A US
market spec Volvo rear wheel drive turbo doesn't have a locking converter.
If yours has a locking converter the ID plate on driver's side of gearbox
will read "03-71L" or possibly "03-70L" if someone has changed it.
The lockup control in either case is a function of it being in 4th gear
and governor pressure reaching approx 50 psi. A lock/unlock at threshold
of locking speed can be caused by a worn bushing in tailhousing allowing
the gov. pressure to fluctuate. This can be checked by attaching a trans
press. gauge and reading the gov. pressure at speeds around 45-55 mph to
see if the pressure is stable as speed is brought that range gradually.
Damage in Park. [Query] I have a 1986 740 GLE. I took the vehicle
for emissions testing in March. Part of the test is to rev the car for
several minutes while they check the high idle (2500 rpm). My transmission
started slipping badly when I left, and lost all forward gears the
next day. I replaced it with a junkyard tranny (I know its a risk, couldn't
afford a rebuild) and the car has run great for about 3,000 miles. My tags
have expired, so I went back for another emissions test (it failed the
first time). Unfortunately, it failed again, but this time, it would
hardly move. I made it about 1 mile, then had to be towed. I was told by
a transmission shop that the ZF 4HP22 transmission cannot be revved in
park without causing damage and that a bulletin
went out to all emissions testing facilities. A dejanews search found several
old posts saying smog tests would kill this transmission, something about
after being in forward gears then put in park, some pressure is still on
the clutches and will wear out clutch pack A. This seems to apply to Volvos,
BMWs and Jags with the ZF 4HP22 transmissions. The emissions testing
people have called me 5 times since yesterday, they seem concerned and
are having my car towed to have the transmission checked. They will not
admit to any bulletin, but obviously seem concerned about liability.
My question: does anyone have any info on these transmissions? I have heard
of a Volvo bulletin on this, and
an EPA bulletin (may be just California EPA, not sure). Bulletin numbers
or a copy of the bulletins would be great. I'd like some facts to present
them with since they are listening, but so far just have a little info
from old newsgroup posts, and from a conversation with a transmission
[Response 1: Mark Aarabi] What you have
heard and read is absolutely true. Yes, there is a TSB out.(Volvo
TSB 2525, 9/91, for all ZF-equipped 1985-88 740 non-turbos).. and Yes,
there was a memo from EPD to all emission testing facilities about this
concern (at least here in Georgia). What state are you in and do
you have any idea what type of equipment they use for testing? The
software on most BAR97 equipment will automatically bypass the 2500 RPM
section of the test on these particular vehicles. [Response 2: Bruce]
Most all emissions center should be aware of this problem. Other
cars have the same problem that use the ZF tranny. As the one post stated
the test machines will by-pass the rpm test with a ZF tranny. The emission
shop should replace your tranny. But getting them to admit fault and do
it could be a problem. For others reading this, 1985, 86 and 87 only
740's used the ZF tranny. (Editor's Note: ZF-22 cars have "P-R-N-D-3-2-1"
on the shift quadrant and NO overdrive button on the shifter.) Turbo models
use the AW-71. For the above model years, if the gear shift lever does
NOT have an OD button you have a ZF tranny. With an OD button you have
the AW-71 tranny. One way to test the emission on a ZF tranny is
to raise the back wheels off the ground, put the car in drive and rev it
up to 2500 rpm for testing. In gear it will not do harm. In neutral or
park and revving, the tranny pump does not pump oil. I was told this
by a transmission repair center.
[Editor's Note: Summary
of Volvo TSB 2525, 9/91:] Before beginning the "High Idle Emission
Test Sequence" make sure the car is at operating temperature. Place
transmission into "park" and switch the ignition off for 30 seconds.
Restart, but DO NOT move the selector through the forward or reverse gears
before or during the test and DO NOT EXCEED 2000 RPM. The first stage
of the test is at 1850 rpm for 30 seconds, the second stage is at normal
idle for 30 seconds. If you fail the test and have to do it again,
then DO NOT proceed with the programmed catalyst preconditioning test sequence.
Abort the test, place the transmission into "park", precondition the catalyst
at 1850 rpm for 4 minutes, then allow the engine to revert to normal idle
and check the tailpipe emissions. Under no circumstances must you
exceed 2000 rpm during any part of the test.
Fails; Swap for AW? [Query:] The ZF4HP22 tranny in my '86 740
just started spewing fluid from inside the bellhousing (1 pint/mile). Given
the reputation this tranny has, I'm undecided as to whether I should rebuild
it or replace it with an AW71. Has anyone done this swap? [Response:]
Do the swap. Any AW70 or 71 will work from 82-on. The basic gearbox is
the same, but some are better or stronger than others. If you're going
to buy one from a junkyard, get one from the latest years possible. (89-93
non turbo, since they have a lock-up converter.) If you use an earlier
gearbox, you will need to plug the speedo drive hole in the output shaft
housing. I don't remember if the flex plate is the same or not, you
may need that. The driveshaft is different. If you order it from the boneyard,
tell them you're doing the conversion. Remember that the car didn't
know what transmission it was going to get, so the interchange is ''bolt
in.'' I think if you get the necessary parts (with relatively low
mileage) for under $1000.00 you did all right.
[Response 2: Dick Riess] Actually
quite easy to do. Best bet is contact someone like Strandbergs in
WI 800 448 5121 and they literally send you a good used unit plus all parts.
I did an 86 740 couple of years ago and works great. BTW, be sure to put
a new rear main seal in at the same time. Here are the parts
you will need: transmission, cross member, motor mount rear, drive shaft
front half, gear selector unit, relay for overdrive on AW unit, some wiring.
Get good wiring diagrams to help you out.
With AW-30/40 Has Busy Shift: Electrical Glitches. [Query:]
I have a '92 960. The car has 95,000 miles. I have noticed that the car
seems to shift frequently. The best way to describe it is that it is "busy".
It is more pronounced in traffic when there is a lot of stop and go. It
seems as if it slipping in and out of gear. I have had it at the dealer
twice and they agree it is "busy", but can not give me a reason. Any ideas?
[Response: Abe Crombie] The mileage
on that car and the symptoms make it a candidate for a failing throttle
position sensor. This can be monitored by their Volvo scan tool on
a drive while it is overshifting. The transmission computer uses this signal
read directly from TPS by Fuel computer which passes it on to trans computer.
You could unplug the TPS (this will set code/turn on check eng light) and
drive the car and see if it shifts less and holds gears better. There will
be a default signal from ECM to TCM when the signal is missing.
[Query: Similar Problem] '93 960 ran smooth and quiet before I brought
it in for tranny service, and it still does. But since the servicing, the
tranny searches around a bit at times. The tach indicator will jump forward
and back, then forward again, and ther car lurches. [Response: John
O] Changing ATF will not make the trans act up unless someone put in the
wrong fluid (like Ford Type F, not likely). What I've seen a couple
of times with early 960s (especially '92s) was a corrosion (oxidation)
problem affecting the large electrical harness connectors on the left,
upper area of the transmission, seen from under the car and near the dipstick
area. Remove the plugs from the bracket, unplug them and spray inside with
electrical contact cleaner, let it dry then re-install with silicone dielectric
grease smeared insided the wire connectors. I've seen this help a couple
of our customers who previously experienced unusual trans problems and
worth trying before condeming the trans itself. [Tip from Tom Irwin]
Those connectors can be hard to separate: use caution, they crack easily.
Diagnostic Codes for AW-30-40 Series Automatic Transmissions.
[Tips from Tom Irwin]
These electronically-controlled transmissions
also contain a diagnostic code series that you can access easily from the
engine DLC module (the same one as used for the ignition and fuel injection
codes.) Note that this procedure for code retrieval works only for
OBD-I (pre-1996) 960 cars.
1. Open DLC, (Diagnostic Link
Connector) insert Test lead into hole #1.
There is also a self-test mode you can enter
which is a two man job. One enters the code through the DLC and the other
guy is under the car feeling for each solenoid and other device to activate
in sequence. Then, you can run through all the gear positions and modes
and the DLC will respond with a code that shows the input was good or not.
Good for isolating bad components.
2. KEY IN position 2, engine NOT running.
3. Push and hold DLC button for >1second,
but, <3 seconds and release. (have your pen and paper ready)
4. Codes are three digits, separated by
pauses, so a "314" would look like: " -*-*-*- (pause) -*- (pause) -*-*-*-*-"
5. After a longer pause, additional codes
will be given, when you see the first code again...you have returned to
the starting point.
6. Code "1-1-1" means all Clear, no codes
7. To erase codes, al codes must have
been read off at least once, then press and hold the button for >5sec.
release, wait for LED to light, then hold button for >5 sec again. And
you are cleared.
Maintenance FAQ for 7xx/9xx/90 Cars
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