The car is an 83 245GL; M46 w/ O/D.

I lost the overdrive and my speedo and odometer right at the same time recently. First I thought they were separate issues and I have changed the cable and swapped out the whole instrument cluster thinking that it could be either. Also then checked both clusters by driving the cable with an electric drill. Speedo and odo in both clusters all work out of the car.

I've also checked the connections to the OD solenoid and swapped out the relay with three others (not know to be good though). The green indicator comes on and I hear it click, but no OD.

I'm no good at electrics, but was willing to try the above. So now that I remember that I lost both at same time I wondered could they be connected by something being wrong with the OD unit or speedo drive?

Right when this happened I got a couple of noisy starts at junctions and it seemed like I had lost the clutch all of a sudden. But now it runs fine otherwise. Anyone had anything like this happen? Any advice? Thanks all.

Check the fluid level in the trans. Low fluid would lead to no OD and if too dry the speedo drive gear would strip out and not drive.

At this point replenishing the fluid would not restore the speedo. I think that will take a new driven gear.

Duane

Hi Duane;
Thanks for your answer. But now what if the trans fluid level was OK? And is the speedo drive gear replacement a driveway job? What's involved with that?

If fluid level OK and OD lost, suddenly, does the solenoid on the OD click when power applied? Does the dash light come on?

The speedo and the OD lost are two separate occurances that just happen to occur at the same time. That is if you can move in gears one through four.

The speedo is driven of a gear jammed on the output bell of the OD. Inside this bell is the driven race of the Sprague clutch for gears one through four and the annulus gear of the planetary set for OD. As long as the car moves in or out of gear, the bell is turning since it is atteched to the driveshaft.

Yes, the speedo gear is changeable without the OD being removed from the vehicle. Just remove the clamp from the OD and the carrier and gear will be removable.

Duane