Over 10 miles for OverDrive to work

eradics · Post by **eradics** » 28 Sep 2006, 06:16

my 91' 740 will not go into overdrive until at least 10 miles go by. then i have to pull over and go through gears. I replaced overdrive relay to no avail. anyone know about this? I hear BMW's have this issue too.

thanks
Ed

Post by **billofdurham** » 29 Sep 2006, 13:02

Other things to check:

Gearbox oil.
Overdrive solenoid and wiring.
Switch in top of gear lever.
Gearbox inhibitor switch.

Bill.

brucepick · Post by **brucepick** » 09 Oct 2006, 06:22

eradics wrote:my 91' 740 will not go into overdrive until at least 10 miles go by. then i have to pull over and go through gears. I replaced overdrive relay to no avail. anyone know about this?...thanks
Ed

I suspect the tranny fluid as suggested by billofdurham. It seems like something has to get thoroughly warmed up for your OD to work.

Don't know if yours is automatic or manual.

Especially if it's an auto tranny, I'd do a good thorough fluid flush, or get one done. There might be some partially blocked passages that restrict the flow till things get thoroughly warmed up. If its a standard tranny then it could be the same issue - but I've only worked on the auto ones.

hertfordnc · Post by **hertfordnc** » 10 Oct 2006, 08:23

I second the tranny flush. My overdrive was taking as much as 50 miles to work rigth. It worse as the weather is cooling. I drained and replaced the trans. Now it engages much quicker. Obviously it's still not right. I need to have a proper flush done but I'm still researching how the OD works and deciding weather I want to open it up and look for something specific to clean or replace.

dave