mj1pate

Folks;

There's plenty of info within the FWSM and elsewhere about the A/T service (trans fluid evacuation/fill) procedure. Are there gotchas that you can identify that only experience would illustrate? Thanks in advance....

Mike

atb

Make sure you get the updated pan gasket.
While the tranny pan is off, eye ball the contact surface around the mounting bolt openings and make sure they are still flat. (may need to take a ball peen hammer to them)
Make sure to drain the converter. You will need to turn the motor until the converter drain plug exposes itself in the access window at the bottom of the rear bell housing.
Pull the screen in the fill reservoir when refilling, or you will be there for a very long time.

Bill Ball

There is an o-ring in the fitting in the tube connecting the reservoir to the pan. It is not part of the service kit. It is an eventual source of small drip-leaks. A rather expensive o-ring, but worth replacing every 3 changes or so. There is a seal in the reservoir cap that if deteriorated or missing can be responsible for puddles on the garage floor when the car sits for a few weeks. Not a routine service item, but worthwhile to keep in mind if you see a puddle on sitting.

Filling the reservoir is tricky due to its location. Various techniques have been used. If you are doing this on a lift or high jackstands, then a bottle pump works fine. On the ground, there is not enough room. One solution involved threading a hose through the gas tank access hole in the rear hatch area floor to the reservoir. The fluid level must be checked with the car level, although it need not be level while putting in the fluid. You can check the fluid level with the car on the ground by using a mirror and flashlight.

The refill amount from a drain is about 8 qts. Dry fill is 12 qts, which would only be after a tranny rebuild. You can put in 7 qt or so w/o overflowing the reservoir, At that point, very briefly run the motor and move through the gears to suck more into the transmission and lines, stop the motor and continue with the fill. As you approach 8 qts, start the motor and run through the gears again, then put it in park and leave the motor running while you finalize the level. You need to get the tranny warm to use the upper fluid level line. It would be wise to get it close, then drive the car for 10-20 minutes and recheck.

I've used M1 synthetic at $6+/qt and Shell DexIII at $1.89/qt. The synthetics are touted as running cooler. Maybe, but I could not tell any functional difference. If you change your ATF like religion every 30K miles, as I do, there may not be any difference.

mj1pate

Yes...I see that in the manual. I did not see a torque spec for the TC drain plug in the torque rating portion of the WSM. Is that another case of making it "good and snug"?

Mike

Ed Scherer

My '90 through '93 Tech Spec booklet says 14 Nm (10 ft lb)

the flyin' scotsman

There is a spec............14Nm for both drain plugs; pan and TC.

If you have the car on a lift wear a Poncho.............the oil goes everywhere.

marton

Undo the fill plug before you undo the drain plug; it is easier than inverting the car to fill it through the drain plug if you should happen to have a stuck fill plug.


Marton

mj1pate

I understand that the vent hose at the top of the reservoir can be a source of leaks, but I don't detect any sepage from the top area. I did notice that there was virtually no way to feel the hose (or barely see it) from under my 86.5. Do you have to drop the exhaust pipe to reconnect the hose, once your reinstalling the pan/reservoir?

Mike

Imo000

Marton,

This is true for the manual trans but for the auto, the fill point is the reservoir, so they don't have this issue.

the flyin' scotsman

Mike.............yes the hose is a source of leaks and virtually impossible to get to with everything in place.

You can either drop the resonator portion of the exhaust or drain the a/t reservoir, remove it from the pan reach up and re-attach the hose. as Bill points out above the O ring and cap gasket should also be inspected/replaced.

marton

Ah so, must remember not to answer auto questions

Marton

mj1pate

I think these answers pretty well fill the gaps, but for a few:
1) I assume there are washers for the drain plugs on the pan and torque converter. Do these need to be changed out during the service?
2) After the torque converter is emptied and replugged, I assume that it will properly refill during the transmission refill process that Bill decribed. That is, extra steps are not necessary for the torque converter to refill?

Mike

the flyin' scotsman

1) yes, they should be changed; the crush washers are included in the service kit as supplied by 928 Specialists

2) correct; the TC is filled through filling the transmission reservoir

mj1pate

I start the service tomorrow and feel squared away to begin. Before I start, I wanted to pose a couple of last questions:
1) The manual does not recommend using a pan gasket sealant and that probably speaks for itself. If you have done this operation as per the manual and have achieved the expected results and do not suggest using a sealant (like Yamabond) feel free to state. If you had to resort to a sealant, and it worked satisfactorily, please mention the circumstances.
2) The manual suggests first draining the fluid by loosening one of the oil cooler lines. Would this require yet another compression washer replacement? Is draining this way recommended, based on experience?

Thanks;

Mike

the flyin' scotsman

1) No sealant required with a new gasket; ensure the pan bolts are torqued properly.

2) I drained the transmission and TC throught the drain plugs; never touched the cooler lines. One could argue that there is residual oil in the lines and cooler that should be flushed for a complete change..........I didn't and the tranny is fine after the service.