As I sometimes do, I backed my 85 245 wagon up the incline to my garage the other day. As I released the clutch, the OD seemed to slip a small amount before it engaged. The car has 246K miles....M46 with OD.
It wasn't the clutch slipping.
I understand that the OD unit has a mechanical 1-way clutch that will engage if the clutch/cone (wrong terminology) fails/slips while going forward, but will not assist when going in reverse. Does the problem sound like the friction surface is worn out in the OD unit? What else could it be? Likely to fail suddenly?
Thanks in advance
steve

Start with a fluid change and cleaning of the solenoid.

Slippage in reverse is more prevelant from a fluid restricted solenoid than worn lining. And since yours slipped then caught, kinda reduces a worn lining cause, which would have continued to slip instead of grabbing.

Remove solenoid and remove the plug from the brass barrel to remove an inner piston. A real PITA. DO NOT try to separate the black coil body from the brass barrel. A crimped fit which does not repair!

If you want a set of instructions for the solenoid, e-mail me and I'll attach them to a reply.

Duane

Try changing the fluid and cleaning the selonoid.