Truck is a 97,2500,4x4,auto. Belongs to a buddy. Speedometer would work fine sometimes and then starts jumping around. I replaced the two sensors, the one on the tailshaft housing and the one on the lower left side of the tranny case. Now speedometer wont work at all. Any ideas?

 

The ABS sensor in the rear diff actually drives the speedo. Sounds funny I know. Pull the harness off the ABS sensor and go for a ride and see if anything different happens. My friend with a "99 had a problem with his trans not shifting. Ended up being the trans sensor. You would think that was for the speedometer, but its not.

Keep asking around and you will probably get the same replies.

Ronnie