My speedometer ignorance is showing

I've been having trouble with my speedometer for a few months, but it has quit on me now. It's a replacement. Been in the jeep for three or four years. About 6K on the odometer.

Last week it quit registering speed. However, the odometer still works. The gear in the xfer case turns the cable when the jeep is in motion. With the cable disconnected I can turn the speedo and the needle bounces.

When it is all connected the needle does not move. Except, that it will occasionally jump to 40 or 50 mph and lock there. The needle will fall to 0 when I disconnect the cable from the head.

Any insight out there?

 

It's easy enough to pull the cable out of the housing and make sure it's in good shape. If it is put some graphite lube on it and put it back in. If your odometer is working and speedometer not, you've probably got a bad speedo. Before you chunk it open it up from the back and squirt some graphite powder in and see if it helps. Make sure you find a hole in the back that get's to the gears.