91 Navajo speedometer revolt

[phantym]

I have a 91 navajo and the speedometer did not work when I bought it. I just changed the speed sensor today and it still does not work. I took the bolt loose to try and diagnose the problem and drove around the block and at about 35 to 40 mph the speedometer would bounce. After I put the bolt back in, it wont move at all. I hooked the cable and sensor to my drill before installation to make sure everything worked and it did. Does anyone have any other suggestions?
Thanks

 

[RedneckRambo]

I have a 91 navajo and the speedometer did not work when I bought it. I just changed the speed sensor today and it still does not work. I took the bolt loose to try and diagnose the problem and drove around the block and at about 35 to 40 mph the speedometer would bounce. After I put the bolt back in, it wont move at all. I hooked the cable and sensor to my drill before installation to make sure everything worked and it did. Does anyone have any other suggestions?
Thanks

does it have a speedometer cable or sensor?

 

[phantym]

It has a cable that connects to a speed sensor on the transfer case.

 

[RedneckRambo]

It has a cable that connects to a speed sensor on the transfer case.

hmm. ok mine was off by about 5 mph when i would get up to 65 and when i let off the gas it would shoot up to 70. after taking the cluster out of the dash about 4 times i discovered the the nut behind the yoke on the transfer case was loose, which was allowing the gear on the output shaft of the t-case to slip. after we tightened it up its worked just fine. maybe you should tighten that nut and see if it helps. if that doesnt work maybe the speedo cable is broken inside the housing somewhere.

 

[Maniak]

The speedometer is cable driven. That speed sensor is for the computer to control the Cruise Control.

Since the speedometer worked when you hooked it to a drill and it "sort of" worked when you had the bolt out, it sounds like the problem is with the "drive gear". The Drive gear is in the transfer case and it spins the driven gear that is on the end of the speedometer cable. I am assuming the driven gear on the end of the speedometer cable isn't worn.

To replace the drive gear, drop the rear drive shaft from the rear of the transfer case. Take off that Big nut off the pinion on the rear of the transfer case. Pull the pinion off. Now you can pull the drive gear.

Its been years since I've done that on our X so I can't be 100% sure but I don't remember there being anything holding it in there.. I think I just put something in the speedo cable hole to push the drive gear towards the back and I just took it out. Our drive gear had worn quite a bit over the 250k or so miles it was in there (I think that is when I changed it).

~Mark