NEED HELP WITH OVERDRIVE!! ROOKIE QUESTION!!

[dakota farmer]

Ok this may be a stupid question. I replaced the throttle position sensor with a potentiometer run in the cab and it worked great. Shifted perfect every time. NOW it won't shift. The speedometer on the truck doesn't work right now ....would that affect the shifting of the tranny into overdrive.Someone else has been driving pickup on farm and I don't know if it quit shifting the same time the speedo quit. I appreciate the help guys. Thanks.

[ellis93]

Yes the speeder meter needs to work for O/D to work.

[winkgnz]

I had the same problem about a year ago, it turned out to be the VSS (vehicle speed sensor) was bad. I wnet through three of them from NAPA and one from CarQuest only to find out that the aftermarket ones are JUNK!
Go to your local dealership and and hopefully you can still get one from them. that is what I had to do. Also if it's a 4x4 make sure that the ratio adapter on the side of the transfer case is still working as that was also bad on mine.

[Fred Average]

Is there a way to bypass the VSS so the trans DOES shift into overdrive?

Have the OEM part number for the VSS?

My 1992 D250 is doing the same thing.

Thanks!

[Fred Average]

Well as per MOPAR,the VSS IS NO LONGER AVAILABLE

Part # 4638763

Anyone know of a source or a quality aftermarket replacement?


Thanks All....

[Diesel]

I had the same problem about a year ago, it turned out to be the VSS (vehicle speed sensor) was bad. I wnet through three of them from NAPA and one from CarQuest only to find out that the aftermarket ones are JUNK!
Go to your local dealership and and hopefully you can still get one from them. that is what I had to do. Also if it's a 4x4 make sure that the ratio adapter on the side of the transfer case is still working as that was also bad on mine.

Now when the VSS went out did you lose speedometer or just the OD hunting issue? My truck speedo works but the OD kicks in and out when cold for a while. Once warm it stays in OD generally.