I noticed today that under certain situations and circumstances my speedomter did read accurately. Mostly going up hills in third. Well, it would fluctuate a few MPH on either side of the actual speed. (Actual speedo was found using a portable GPS)

What can be contributing to this? What should I replace to ensure this isnt causing other problems with the tranny?

Thanks
Thad

 

You might have the electronic speedo that uses the speed sensor in the rearend for it's signal. If you do, you can check the wiring and the sensor back at rearend.

 

Small amounts of metalic debris in the differential can get caught on the magnetic pickup of the VSS, and will cause irratic readings eventually. You can pull the sensor easily and clean it to see if thats the problem.

 

Got pics or directions so that I can locate it?

 

Its located above of the pinion housing in the differential housing, its the only electrical outlet on the casting, you can't miss it (doubles as the rear ABS signal).

 

Thanks, I'll look when its light out.....its freakin early right now...off to work....

thad

 

The VSS was clean off metal. It did have some oil and gunk on it though....I also, looked at and wiped off the Engine RPM sensor.....

Thad