My 47re is shifting in and out of O.D. I have read enough to know the most probable cause is the TPS and I have the test/adjustment steps. My question is, it is very erratic so when I test the TPS will it test good if it in it “on again” mode? Will it only test bad some of the time? I hope I made that understandable.

Floyd

 

If it´s bad, it tests bad, and the other way around.
But you could try drilling that hole that´s described somewhere, to clean it out with compressed air and then spray some oil in it.
Fails that come and go, gotta just love it, huh..

Slev

 

Seems more likely that it's shifting in and out of lockup. Erratic behavior suggests a bad brake switch. Next time it's doing it, hold your brake peddle up with your foot and see if it stops.

 

oh thats right, these older trucks unlock the tc when the brake is pressed- i used that trick to unlock the converter on slick ice to reduce torque way back in the day and forgot about that trick

 

Thanks for the tips. Not sure about the OD/lock up thing, I know my RPMs increase about 3-500 RPM when it happens then go back to where it should be.

Floyd