Ok i have a 93 4x4.Speedo quit and it was the terminal corroded and broke.Got another one from junk yard.Lasted a month.Pulled the harness and one terminal was real loose.cut harness and made new spade terminals.Worked for a day.Ordered aftermarket ,pulled old noe out.Plastic gear stripped.So i had and extra gear and went ahead with the new sensor.Still doesnt work.Is there suppose to be 12 volts with key on going to sensor?If there is where does it get power from?I do not have any voltage on the three wires.

 

ok i do have voltage afterall.I will change out gear to ols sensor and see if it works.

 

ok pulled new sensor and the teeth on this gear is flattened now.The worm gear looks ok,very little play in out put shaft.It quit when i went into reverse the other day backing about 200 ft or so.Then when i went to go forward it didnt work thats when i assumed the senor was bad.I replaced the output shaft seal and u joints 300 miles ago and the companion nut went about a 1/8 turn past the stake on the shaft w at 90 ft lbs.
Did something happen there?

 

pulled back plate on transfer case.The worm gear for the speedo had smashed places on the gear.The oiler gear behind it hade a little spot.Looks like it rubbed inside case a small place.I am assuming bearing has enough wear for it to rub,also a very small piece of aluminum looks like chipped off where the sensor plastic gear goes toward the inside .
Anyway ordered plastic gear,worm gear,oiler gear,bearing.Anybody run across this?