OD problem with 86 Toyota

I have a 1986 Toyota Mini Motor Home, Automatic transmission with OD and a 22 RE engine. At a steady speed of 55 or 60 MPH, the OD kicks in and out. After doing that 4 or 5 times it kicks out and will not go back in. Does anybody have any suggestions? Thanks in advance from a newbie.

hey suzy, I am kinda new here too. I am sure some of the people here would have a better idea than me of what your OD problem is but I did read about a relay switch that could be a possibility.

Are you saying the OD no longer works at all, or after 5-6 in/outs it won't go back into OD until you drive it again?

At 60 MPH or so the OD should not be used (under most driving conditions), as evidenced by it's in/out behavior. The weight of the truck and that little 4 cyl engine just can't handle it. It's not good for the engine or transmission.

If it's totally non-functional it may be the OD solenoid in the tranny, or possiblly the trannies ECM.
When's the last time the tranny was serviced ? the fluid checked ? is there a tranny cooler ?