1989 760 Turbo overdrive issues

I have a 1989 760 turbo with 195,000 miles. Automatic transmission.

Overdrive functioning has been sporadic at best, functioning most reliably when outside temperature is in the 80s (F) or so. I've replaced both the solenoid and the relay (with new parts), with no change in overdrive behavior. Now that the weather is turning cool, it doesn't work at all -- even after a long drive.

What's the next thing to check?

Thanks,

--Dale

Reply to
Dale James
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Does the solenoid get power?

Reply to
James Sweet

I assume that it does, because the OD works fine at some times.

Reply to
Dale James

Check it though, intermittant problems are often electrical.

Reply to
James Sweet

Could be the return valve spring thats gone, it lives under the plate that unbolts from the bottom of the O/D unit. check here for a brilliant description of the unit, its the same one.

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Reply to
Stuart Gray

But this is an automatic tranny, the OD is located inside the tranny near the front end of it.

Reply to
James Sweet

Really? Sorry, I assumed it would be bolted on the end like the M46. Apologies for bad info. I must take a closer look at my new aquisition. It's got an auto box with over drive, but I must confess I haven't been over the car yet. H Reg with 75,000 dealer serviced miles on it. Runs like a dream compared to my C Reg with 320,000 abused miles on it. Must take a look at the Haynes manual automatic box section to learn it. Thanks for the heads up James.

Reply to
Stuart Gray

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