I have a 1984 f 250 4x4 and my speedometer does not work I pulled the cable out of the transfercase and the gear on the cable looks good and I put a drill to it and the speedometer worked! But I don't u derstand why when I put the cable in the transfer case it will kinda work but not correct then it will go away... Is the gear in the transfer case stripped ? Or am I not installing it right and if anyone has a diagram how the transfercase comes apart so I can replace that gear please help me out

 

Most likely the drive gear in the t-case is stripped. I believe you only have to remove the tailshaft housing to get to it though.

 

thats what i was thinking too ill try that and see if it fixes it thanks !

 

If you can shine a small flashlight in the hole, you may be able to see if the gear is chewed up.