Any ideas on why a newly rebuilt trans...all FoMoCo parts, would stop going into OD and staying there? It will engage into OD, but if I give it the slightest push of the pedal it goes right back to 3rd. It won't stay in OD with a load applied to it. Worked beautifully to this point.
I hate these trannys. I also had mine rebuilt a little while back and have similiar issues. When the car gets hot, won't lock-up. Also like yours, if a fly craps on the gas pedal, it jumps out of OD back to 3rd. It also hops around at certain speeds from 3rd to 2nd or OD to 3rd. Just learned to live with it.
no problems with the trans other than the OD slipping back to 3rd. So smooth you don't even feel the shift.
Are you 100% sure it is shifting from OD to 3? How much does the RPM go up? ANy chance it is just unlocking the TCC?
I was also thinking what Jeff was thinking.
Ok...now i feel really stupid. I think i know....but, what is the TCC? The RPM's only change by about 500-700 rpm. You don't even feel it till its changed. Just slides right into whatever gear or state that its in.
According to one of the symptoms in the service manual, it could be the throttle position sensor needs to be adjusted. The sensor is probably sensing "full-open" throttle when it's not and kicking the tranny down to 3rd. There is an adjustment screw/slot to make the adjustments .... not sure how much to rotate sensor. Mine is doing the same thing .... just haven't had the time to do the adjustment.
I adjusted the TPS to the stock specs with a volt meter. Should I have it adjusted differently?
I, believe, it's a mechanical adjustment, not electrical .... loosen the sensor screws and slightly rotate or slide. I'm not sure which direction.
hmmmmm ok. its worth the shot. I recently found the correct wiring harness for the trans and when I hooked up the wires for the 3-4 4-3 shift and the clutch convertor solenoid, a few days later it stopped staying in OD. W/O the wires hooked up it worked fine. But, now I disconnected them and it still has the problem.