Imo000

I've tried to refill the auto trans on the '89 but I can't get the filler cap off. The last auto trans 928 I worked on was an '83 4-speed and that one had a totally different reservoir. The exhaust was also not in the way like it is in the S4. I can get my hand on the filler cap but can't get a really good grip as the exhaust and other stuff are in the way. Am I doing something wrong?

Mongo

There's a plastic nut on top of some of the caps I have seen. If you take a 17mm boxed-end or open ended wrench to it, you may be able to apply enough force to break that tight seal. I just went through this last Saturday. I feel your pain except I had a Flowmaster sitting on my face while doing it.

DanielD

That fluid reservoir is the worst I've seen.

Mrmerlin

spray the tank with some break cleaner first to get the dirt off of it before you open the cap.
The box wrench should do the trick

Mongo

Who the hell thought of putting the damned reservoir under the car should have been shot.

69gaugeman

Why?

Shouldn't leak, ergo not much need to fill.

Almost all new cars have no dipstick or fill hole except like a manual transmission. Why should the auto be any different?

cold_beer839

There are several engineers involved with the 928 that should have been shot.

Imo000

Thanks for the info, I’ll clean the cap and try the wrench technique tonight.

Rod,

You should drop by and have a look at this. It really is something else. The early reservoir was just a PITA because you had to lift the car. On this one, it’s damn near impossible to get to. There is a heat shield on the reservoir to protect it form the exhaust and then the resonator and pipe are too close to be able to get a good grip on it. It’s like squeezing your hand in a cookie jar and then try pulling it out when your fist is closed.

Cosmo Kramer

On my 85 auto is is a piece of cake to get off, I can actually do it without jacking the car just reaching in with my long arm. Hopefully you can get it off with the wrench. How hard would it be to remove the reservoir from the trans? Mine was bolted to the pan and it came with the pan when I changed the transmission filter.

Imo000

Ted,

On yours, you have both exhaust pipes running on the driver side. On the 86.5 and up, the passanger pipe always stays on that side of the car and passes only a few inches away from the reservoir.

I'll try the wench first and if that doesn't work, then I'll try removing the reservoir. Looks like the TC seal is leaking
and want to top it off before slapping the temporary plates on it.

the flyin' scotsman

The wrench technique should work to remove the filler cap just be careful you dont move the vent hose or the entire reservoir itself.

Once you have the cap off inspect it and the seal for cracks; they can and will leak.

Imo000

Thanks guys...the wrench worked like a charm. First cleaned the area with brake cleaner........got a nice buzz off it! Then, as suggested, used a 17 mm wrench to crack it open. Once cracked open the cap spun off with very little effort. After adding around half a gallon of ATF, the delay between N and D was gone. I'll keep an eye on the level as it apears that the TQ seal is leaking.

Thanks again guys for all the help!

Cosmo Kramer

Try putting some B&G transmission conditioner in it it may soften the TC seal and stop the leak. I put some in mine when I flushed it and it shifts great and no leaks.

Mrmerlin

great that you got the cap off, if the TC is leaking from the grate, it can also be the front pump O ring seal leaking, in fact more likely, it will drip from the same place whether from the radial seal or O ring so replace both.
Now is also the time to figure out if the cooler lines also need to the rebuilt as you will be dropping the trans to repair the leaks so the lines are easy to remove and get new hose put on