another auto tranny problem, need help.

[billy in slo]

90 535, tranny gave no sign of a problem but smoke started pouring out at a stoplight, ATF on a hot exhaust, freaked my wife and kids out, she asked if it was going to blow up, luckily it did not ignite. Any way, light turned and I got off the road and parked it. Towed it home(flatbed) and got under this weekend. There is a 2"x5" window in the bottom of the bell housing where the fluid was coming from. Shouldn't there be a cover plate here? I can see the torque converter spinning and unprotected! Is the fluid in the T.C. ATF?
Could it have gotten debris in there that punctured the T.C.? They are a sealed, self-contained unit correct? Tranny seems fine, still works in 1st and "R". When car was up on jacks and running, very little additional fluid was coming out (it was jacked from driver side so car was no where near level) and ATF fluid level was not empty. Is it somewhat pressurized in that if a seal had blown it would be forceing ATF out while running? Just trying to figure out what be wrong before proceeding with repairs.
Thanks

[JD525IA]

It sounds like you have a seal somewhere inside the tranny that let go.

Yes, they do build up pressure while driving/shifting and the weakest link will show first, usually.

I've never heard of one leaking towards the front end though. It is unsettling when you get the fluid on a hot exhaust and the plumes of smoke come up or you see it out the rearview mirror. I think the flashpoint for tranny fluid is pretty high since it is just a high-grade oil with lots of detergents.

Better get it to a shop. Good luck.

JD

[Gene in NC]

Just had what sounds like same problem on my truck. Could have been blown seal, which can happen, or cracked converter which it was. In either case must come out to tell. DON'T drive it. If fluid too low it will slip and need rebuild. My truck, $600. Rebuild a couple grand or more.

[Kalevera]

Probably blew the torque converter seal. The TC is supposed to spin in the bellhousing, nothing out of the ordinary there. The plastic "grate" offers some protection, but there's not much that needs protecting in there, anyway.

Don't start or drive the car until you get it fixed. If the converter isn't building pressure and allowing fluid transfer, it won't be long before you'll be remachining hard parts.

Although I doubt you will need it, I have a BMW/ZF Life 2 remanufactured transmission for that car that I'd like to sell. Still has about a year left on the unlimited mileage parts/labor warranty, serviceable by any BMW dealership in the US.

I also have a separate torque converter for that trans, if it turns out to be something more complex than the seal. Call me -- 440.564.7574.

Best, whit

[billy in slo]

Thanks whit, I may take you up on the tranny. What do you know about performance T.C.'s. Sounds like interesting upgrade. When I drop or swap the tranny I will be installing the 4.27 LSD and maybe a new T.C.
b

[Kalevera]

Frankly, I'm not sure why or how changing the stall speed would be useful on a 535 that's driven on the street. I can see why one would change the stall speed for racing or other applications, but I think it'd be more of an annoyance around town than anything else. I'm also not sure how it would affect shifting, as engine speed as dictated by the DME is a factor in the EGS telling the transmission when and how to shift. Doubt there'd be any problems off the top of my head, but who knows.

By the way, TQ = TC in my earlier post :)

best, whit