Dean_Fuller

I am trying to put the TC back in the trans after a TT and TC bearing rebuild. The transmission has always dumped fluid after sitting a couple days so I thought I would look for possible leak areas. Before installing the TC I removed the next plate in the trans.

PIC 1......There is a seal that "seals" to the TC that I thought could be my trouble.

PIC 2...After removing the cover plate I see 2 white O rings as well. Are these things I need to replace at this point? Have I gone to far???

PIC 3...When I removed the cover a large drum wants to FALL out and the bearing in this pic is just loose and moves around alot.

I KNOW NOTHING about a tranmission...NOTHING! Have I messed something up taking this front plate off? Could these parts be my problem with leaking fluid after sitting a few days? Anything else I need to skew up before moving on???

Dean_Fuller

BTW...I do not have a PET for this year car (1989) so an exploded drawing I know may help.

Mrmerlin

Dean in the first picture you do want to install a new radial seal.

The 2nd picture you will leave the white teflon seals alone.


In the 3rd picture you want to replace the large O ring thats on the outside of the front pump,
I suggest to use Dow Corning 111 on this O ring so it will stay soft and slide easily.
Also there is a gasket stuck to either of the mating surfaces dont mess with it,
other than wiping it off

Also behind the TC radial seal is a bronze bushing put some vaseline on the bushing before installing the TC.

hb4

Hi Dean,

Not sure why your trans would wait for a couple days to drop fluid; could you see fluid at the TC drain hole, or was it back by the reservoir?

The seal you point to should be replaced; it is part of the Primary Pump assembly which you have removed. Might as well replace the two split seals as well. Here is Bill Ball's famous 'screwed' thread which might help.

Also, this thread shows a problem I had with the Primary Pump main gasket because I did not replace it the first time I had things apart. That should be replaced and the sealing surfaces cleaned well.

There are some seals inside the Primary Pump which require the Pump to be disassembled. We replaced them as well when we had things apart. The lip seal is tricky and we had success only when we used a flexible plastic disc to help it along. We did two ATs last winter, and on both of them we ruined the new seal the first time we tried it without the lip seal tool. On one we re-used the original seal without problems. Someone can correct me, but i believe the internal seals only seal Pump pressure and do not cause leaks to the outside of the AT.

the flyin' scotsman

Dean.......check the reservoir, the collar and vent hose for possible leak sources.

ROG100

Malcolm,
Thanks as that saved me a job. Promised Dean to send him the PET illustration once I returned home from shipping LOTS of packages 8>).

Dean,
If the car is sitting the fluid all drains back into the pan. The level goes higher than the reservoir cap and the seal in the cap leaks allowing some fluid to leak out. A couple of drops on the floor soon spreads into a large diameter puddle. Take of the cap and turn the seal over and see if that makes a difference. Follow Mr. Merlins advice on seals. Let me know what you need and Santa can deliver a couple of days late.
Roger

the flyin' scotsman

no worries Roger.....had PET open

ammonman

Since you are this far in now is the time to correct any delayed engagement of R or slipping when in R. Correcting this requires replacement of the B3 clutch discs and steels which sit behind the drum in pic #2. The drum is the K1 clutch pack. The loose bearing has shims behind it that set the spacing between the K1 clutch, bearing, and nose of the B3 piston (the thing with the long tabs in pic #1.) I had good success getting things back together from this stage by strapping the trans to a moving dolly and standing the whole thing up on the differential. Made getting the primary pump back in a breeze.

Mike

Dean_Fuller

Cool...thanks all for the input.

The only shifting problem I have had was a HARD upshift only sometimes. Also at hard excel its holds the shift too long ( for me) ...I think ALL OF THIS IS due to the THE MODULATOR.?.?

All of this was to try and stop the leak / sitting issue...but that just might be a leaky res cap as Roger says. Will see.

GregBBRD

The pump "0-ring" (#3) is almost always the source of any leaks from the torque convertor area. I usually replace #11 and #12, when I take the front pump apart.

Stan says not to replace the two white teflon rings (#9, which you pointed out in your 2nd picture), but I always replace those and gasket #10....which is a bitch to scrape off.....but is paper and something I just can't leave without replacing.

90% of the time, when there's a leak after these cars have sat for a couple of days, I find that the leak is coming from the o-ring on the kickdown cable tube (999 701 964 40). If I were you, I'd get one of those, also.

Dean_Fuller

Okay...thanks Greg.

Where can I find the PET for my 89 car? The page flagged above by Malcolm ( thanks ) does not show all the part numbers I need.

Speedtoys

I use this:

http://www.autoatlanta.com/porsche-p..._928_parts.php

Mrmerlin

the reason for not recommending to replace the parts that I mentioned is that the teflon seals if they are not fully seated ,
can get pinched and fail , this can happen if they are opened too wide when fitted.

The same for the paper gasket if it is not damaged simply wiping it off will be fine ,
as one side will be securely stuck and you will be pissed after making fresh gouges in the surfaces.
otherwise the cleaning process will usually cause more damage to the mating surfaces

The part thats usually the leaking part is the front pump O ring.

Since Greg rebuilds more of these transmissions I would defer to his experience

hb4

Stan,
On my AT, I should have replaced it the first time I had it apart, but since it was stuck to the Pump and there were horror stories about scraping it off and damaging the pump, and since it looked good from the side we could see, I decided to leave it.

It leaked, and after removing the AT for the second time, taking everything apart again and peeling off the gasket (it came off just fine), we found some old thread sealant under it, which was reflected in an over-compressed section of the gasket.

The old gasket didn't re-seal in that location when we reinstalled the PP and when we put it all back together and did the refill procedure it leaked. Remove AT, remove PP, remove gasket, remove sealant, new gasket, reinstall PP, reinstall AT, and no leak. So...... better to spend time carefully scraping and replacing the gasket the first time - in retrospect. There's some photos in the second link I posted above. 8 hrs AT out and back in vs 1 hr working on the gasket surfaces while it's out the first time.

GregBBRD

No experience on re-using one of those gaskets. Trust me, I much rather not ever remove one of them....it's a real pain in the butt and "sucks up" some serious time. I've just never had the ***** to re-use one. Way too much time to go back and do it over.