Engine/Transmission (1994 - 1998) auto shift problem

[rbshowpig]

my truck is shifting going down the road at 60mph to drive to overdrive. it can't find the gear. is it my tps. #@$%!

 

[Joe G.]

We need a little better description of what it's doing. The shift sequence for the 47RH transmission is 1 - 2 - 3 - OD - TC lockup if OD is not locked out. If OD is locked out the shift sequence is 1 - 2 - 3 - TC lockup. Third gear is considered high gear because there is no gear reduction. 1st, 2nd, and 3rd are in the main transmission. OD is in the OD unit in the tail shaft. TC lockup is in the torque convertor. A bad TPS can cause problems with OD and/of TC lockup.



What do you mean by "it can't find the gear"? Is it failing to shift? Or is something else happening?

 

[BigPapa]

Welcome piggy!



I've read lots of fixes for the "Lockup Hunt". The only one that ever worked for me was to replace the TPS. I went through three of 'em before going to the NV4500. Fixed the hunt every time. I thought I'd give the brake pedal switch a try once and it didn't fix it, but don't forget about it. Mine did go out once and I had to replace it. Good luck.



Scott

 

[rbshowpig]

It Shift From Drive To Overdrive And Back To Drive And Back. it Can Not Find What Geat Drive Or Od.

 

[Joe G.]

That certainly sounds like a TPS problem if you mean 3rd when you say drive. Drive is a position on the shift lever not a gear. Cleaning the TPS might work. Some have got by with spraying the where the rod comes out of the TPS and working the linkage back and forth. If that doesn't help you will need to open it up to clean it. That might not work either. There are other solutions. Take a look at this thread:

https://www.turbodieselregister.com...mission-1994-1998/156901-tps-myth-buster.html