hi there im new to this board and just recently have gotten my 1997 f150.im really into old style hotrods and customs and finally got a truck that can help me build them and be very happy driving it too.anyway i saw the door ajar wd40 fix and am gonna go right out and fix that once i get off here.but im haveing the jumpy and now dead speedometer.this is very frustrating.i paid out cash to thew guy i got it and have no warranty.i looked in my books to see the speedos whereabouts and cant find any thing out.is this gonna be a dealer fix only and how much $$ am i gonna be dishing out?any help would be great.thanks dusty

 

On 97 & 98's there is a plastic gear in the Variable Speed Sensor on the Tailshaft Housing of Tranny if 2WD and Transfer Case if 4x4. Just one bolt to take off, pull straight out and look at teeth, if stripped replace. Cost appox 12 bucks at dealer. They go by color. Hope it is a cheap fix.

 

well i checked it out didnt look like it was striped.maybe the one on the inside .gonna pull off my driveshaft and check.its really not cool that its doning this.the odometer.speedometer none of the speed miles equipment is working.any other ideas.i took it to a dealer and of coarse they were saying its the speedometer head mostlikely and it was gonna be 500 bucks to fix and they wanted to hook it up to the diagnostic......oh boy.thanks though

 

Remove the wiring harness near the Sensor. Check for voltage to the sensor with the key on (engine not running). you should read 5 volts. If no voltage have the PCM checked. Another test is with the VSS on the bench. Backprobe the harness connector using two pins and while slowly spinning the gear, observe that the voltage signal pulses from 0 to .5 volts. Use the AC scale on the volt meter. I got this out of a Haynes Repair Manual.