528e Tranny won't engage forward

[mmbuster]

My 1986 528e was used to jump start another vehicle, ran it for a minute or so in Park @ 2000 rpm per owner's manual instruction, got other vehicle started, reversed away from other vehicle, put selector into Drive and car would not move forward. Tried all other forward options, no go. Reverse works just fine. Checked fluid and it was low. Topped it up but still no forward gears. Had vehicle towed home. Checked selctor cable and it is OK. HELP! Any ideas? What could this be to go out all of a sudden like this?

[4-Door Flunky]

Sorry, Buster, but I'm completely ignorant when it comes to automatic transmissions.
It is possible that when the other car started, yours received a spike of electricity, which freaked out the computer or god-knows-what in your car's electrical system.
I'd disconnect your battery cable for an hour or so, and pray that this psychotic episode comes to an end when you reconnect.
Good luck!
Flunky

[nokie351]

Dear mmbuster
Hate to say it you've got a bad tranny. I bought a 325i a few years back. All it had was reverse too. Dropping the pan and taking the valve body off to clean it only made things worse. Once I got it back to gether again i lost reverse too. I bought a used trans on ebay and took a chance and put it in. Worked fine for a couple years, sold the car and still see it zooming by on the roads now and then.
Taking it too a shop will cost large bucks. Hey, it says BMW on the car and ZF on the trans, what can you expect? I know where a 528 sits in a yard... Let me know, maybe the guy will sell the tranny out of it.

[kidwired]

its done.
the ZF 4hp 22 tranny in your car CANNOT be run @2k rpm for more than 2 min in N or P. fluid leaks past a seal into the A clutch and pressurizes the forward gears. This burns the clutches out. The leak is 1st noticed by placing the car in N and the car creeps forward or eventually drives when in N, then R goes, then no forward gears at all.
In CA, Smog no longer req's high RPM testing becuz of this.

The cause, turbine shaft seal failure.
there is a ZF correction kit available
To prevent this a .045 hole is drilled in the forward clutch piston to reduce excess pressure.
replace the metal turbine shaft ring w/ teflon ring.
replace the forward clutch orifice or drill out existing one to .093.
cheaper to by a rebuild one, turn your in as a core than to have someone rebuild it.
hope this helps
kid

[D4ve]

why wont my 535i auto drive forward