philvo is correct in that you should be ussing ATF Type F instead of gear oil.

If you added not too much, under 1/4 qt, I would not worry for a while about problems from the ger oil.

Getting on to the no OD problem. Did the dash light stay on when you had no OD?? If it stayed on, check the wiring on the solenoid. Including the ground.

If the wiring is OK, the heat of the extnded use thinned out the fluid enough to blow past the seals on the OD actuating pistons. The extra thickness of the gear oil was the final blow and damaged the seals to the point of no recovery.

It may be time to remove the OD and change the piston seals.

Contact me off board for more info if needed.

Duane