Overdrive Problem

[ALC 68A]

My Series 3 is fitted with a later Series V overdrive gearbox. It has been working normally, but when I took the car out on Sunday after not having been driven for six weeks or so, the overdrive would not work properly. It would engage but almost immediately disengage again. Can anybody suggest a reason/fix please? Regards and thanks. Steve G

 

[puff4]

Check the oil level. If that’s good, move on to check the engagement lever position.

 

[ALC 68A]

Check the oil level. If that’s good, move on to check the engagement lever position.

Thanks for your help. My other half has me on home decorating duties at the moment, but I'll get on with the car ASAP. Steve G

 

[Alpine 1789]

I had this exact same problem a couple of years ago. I first suspected the adjustment of the gearshift switch. Too many shims could produce the same effect, which would also happen if the switch loosened and was no longer engaging. I assume a loose connection could do the same thing. However, in my case, it turned out that my latching relay had failed and would no longer latch. A substitute using Tom H's kit solved the problem.

 

[Tom H]

Do you have a lamp on the dashboard that indicates when the OD is ON? If so does the light go off when it disengages? If so, the problem is electrical. If the light stays ON when it disengages, then it might still be an electrical issue. Most likely electrical problems are , in descending order of likelyhood are: Lock out switch on tranny needs shims removed, lockout switch is bad, Relay is bad, solenoid is bad. How do you, Steve, trace electrical problems ? Digital multimeter? Analog multimeter? Test lamp?

Tom

 

[Ashfried]

Check oil is best idea. I had the same problem, checked everything. Was about to pull OD and noticed the wire runing to the OD had worn bear and was shorting out on frame. Took 6 months of cussing and 3 minutes to fix with heat shrink.

 

[ALC 68A]

Thanks guys. I don't have an overdrive on/off light on the dashboard, because the car was originally non O/D. The wiring loom is brand new, fitted at the restoration, although the column switch and relay are original parts. The O/D worked perfectly until the weekend, so the first check has to be the oil level. Steve G

 

[alpine_64]

With the car off turn the igntion on.
Move the gear lever into the 3rd or 4th gear activate the overdrive switch and listen for the solenoid under the car.

If you cant hear it the solenoid might be jambed or the realy may not be working.