1997 F-150 XLT Extended cab. 4.6L VIN 6, 5 speed manual, 4x4. Replaced speed sensor on transfer case, speedometer is not completely dead but bounces around. Seems to be about 10 mph below actual speed. When I come to a stop say at a red light speedometer drops to zero at about 20 mph or so. Cruise also inop. It seems like whenever I let off the gas to stop or shift gears the speedometer drops down but then goes back up but not to the right speed. Any suggestions? It has the mechanical odometer by the way. Everything else seems to be working fine. New speed sensor did not come with the plastic gear so I had to reuse the old one. Not sure if that gear was bad or not, but it was the pink one if that matters. Please help!!!

 

If yours is a mechanical speedo as you said, I'd start with replacing internal cable from the transmission to the speedo. The symptoms you describe could easily be a broken cable where the two ends periodically still mesh enough to register. Shouldn't need the outer housing just the inner cable itself. If it is broken you may have to remove the cable housing at back of the speedo to get both pieces out of the housing.

 

If yours is a mechanical speedo as you said, I'd start with replacing internal cable from the transmission to the speedo. The symptoms you describe could easily be a broken cable where the two ends periodically still mesh enough to register. Shouldn't need the outer housing just the inner cable itself. If it is broken you may have to remove the cable housing at back of the speedo to get both pieces out of the housing.

 

It doesnt have a speedometer cable. It has a speed sensor instead. And I already had the cluster out to change a burned out bulb. I ordered a speedometer driven gear the other day. Maybe that will help?

 

Sorry about that but I misunderstood your situation, thought you were saying it was a mechanical speedo.

 

Well I fixed it. It was the plastic gear that goes on the end of the speed sensor. The teeth on the old one were worn down in the middle.

 

Glad to hear you got it, frustrating at times but a lot of satisfaction when you find the problem.