Rebuilt A4LD...no OD...

[Weasal]

I have a 91 explorer that had a rebuilt tranny put in last year previous to my purchase of it. When I put the truck into OD, it doesn't lock up. When I move it to D then slowly to OD, it locks up when it feels like & at highway speeds, it will slip out of gear.

This basically has been like this since I got the truck & the guy that put the tranny in will not respond to my calls.

Any ideas?

 

[BrooklynBay]

Welcome to this forum! The PCM (computer) depends upon sensor readings to command the overdrive solenoid to engage. Such parts like the TPS, VSS, or BOO switch may not allow overdrive to engage if there is a problem. Scan your computer for trouble codes first, then check the resistance of the overdrive solenoid. It should be 25-40 ohms. You could also adjust the overdrive band. Other problem areas could be the solenoid, clogged filter (main filter, and solenoid screen), leaking servo, broken or misadjusted band, etc.