Torque Converter Seal suspected, need advice

[Cobra]

Hi, I have an 89 535iA with approx. 156K miles

The car was running superbly until I came back from a 1hr sprint on the highway, when ATF started spilling onto the hot exhaust. Drove for a while confused but then realized what was happening when I felt a slight slip in the tranny on turns. Parked the car and had it towed home.

After reading many archived threads I've narrowed it to a possible TC seal failure. Is this a common thing to go or a symptom of something worse?

Once I pull the tranny what should I be looking for other than the seal? What else should I change or do while I've got it out? I'd rather not dismantle the car again in freezing weather. Thanks.

Take care,
Dan

[aston_jag_tech]

You should fill the trans up again while normal temp. Raise the car or if your only option is to jack it up and crawl unde rit do so. Clean the trans area, run it until normal temp and check for leaks. If no leaks are found, drive a few miles and check again.

You should really look for the root cause before diagnosing a car without looking at it first

good luck.

[shogun]

Before we offer all possible help, find out what it is actually. So lift the car and look for the culprit.
I could imagine it is either the front or the rear shaft seal of the trans.
Front is more difficult, as the trans has to come out.
Rear can be done much easier and that is the one damaged in most cases
http://bmwe32.masscom.net/johan/gearbox_seal/gearbox_seal.html

[Cobra]

Sorry guys, I should have made myself clearer. I have done all the diagnostics and read some archived threads that's why I suspect the TC seal.

ATF oil definitely drips out of the bottom bellhousing hole, my question is once I pull the tranny what should I be looking for other than the seal? What else should I change or do while I've got it out? Thanks.

Take care,
Dan

[shogun]

Yes, ATF oil can drip out of the bell housing hole, but my bet is still the front shaft seal.
Look at the pics I made last year when it happened to my car
http://tridem.han-solo.net/auto/erich/friends/gallery.htm

[winfred]

i find when front seals go in 4hp's it's usually due to the converter bushing walking forward covering the drain behind the seal, i always open up the tranny replace the bushing and do a a-clutch, not sure if you could knock the bushing back into place or with a clever use of tools and skill pull off replacing it inplace, there should be some pics of it under "two zf repairs" or something like in the engine/driveline link from the front page of this site

[billy in slo]

My 89 535iA did the exact same thing with similar mileage. It was not the TC but rather tranny cooler/filter line/hose kinda thing. I am sorry I don't recall exactly, I only know I was quite relieved it was not a tranny failure. Repair was quite reasonable. Did exactly what you described. Leaked out all over the exhaust and smoked like crazy, tranny did act up a little but only due to fluid loss. HTH.

[Cobra]

Thanks guys, so if I understand this correctly there are two possible causes; one being the front seal and another the TC seal? Is this correct?
And, if indeed it's either of these then I have to remove the tranny, right?

Winfred, fantastic write up, thank you very much for sharing.

Take care,
Dan

[winfred]

"Thanks guys, so if I understand this correctly there are two possible causes; one being the front seal and another the TC seal? Is this correct?
And, if indeed it's either of these then I have to remove the tranny, right?"


if it's atf coming out of the bellhousing it's probably the front seal and the tranny needs to come out, if the leak is just near the front of the tranny it could be a cooler line or o-ring on the cooler line which is repairable without removing the tranny

[Cobra]

Thanks again Winfred, it's off to the garage for some serious work.

Take care,
Dan