so i have the same issue as others..speedometer/odometer not working. I go buy a new sensor from the pep boys($30) and replace the one on the transfer case(takes like 1 minute). Unhook battery for 15 and try it and it still doesnt work. Read up some and find out it might be the OTHER one on the rear diff. I go to the store and get another speed sensor and try taking the old one off but im having no luck(am i missing something in trying to take it off?) The only nut i see is the top one(looks like it hold the cables and a square cover plate and the sensor to the diff.) but when i trty to break it loose its turning the support for the hoses as well and i am afraid im going to tear it up, what am i missing..running dual exhaust right by that is def. not helping in the space catagory either..
thanks for any help..

 

At the top of the forum theres a Factory service Manual PDF on a sticky thread, that should help you point it out

 

for the sensor on the diff: there are two nuts stacked on top of each other. one only holds the support bracker for the brake and ebake cable. the second, deeper nut is what holds the tone ring sensor (speed sensor) on. hold the bottom nut with a wrench to keep the cables from moving, then take the top nut off.

i was actually dealin with this senosr a couple days ago. how much did you pay for the sensor for the diff?

if yours is defective, you speedo/odo will not work, and your ABS light will come on.

 

i paid $29 and some change at pepboys..its 3 blocks from my house so it might be a little more expensive than other places but convience factor played a part for me and its a huge pep boys and they have never NOT had a part that i needed (i hav e a 86 cj7-that im restoring and i have personally financiallyadded a good bit to the pepboys empire..haha)
my speedo/odometer dont work but i do not have the abs light on..im wondering if maybe something else might be the issue..ill change the sensor(its a cheap fix) and then move onto the dash.

 

thanks..the manual really helped me out with the oil pressure but i searched and searched for the rear diff speed sensor and only came across it once in the manual and the pic it showed was attached(not an exploded view) radwebster told me about the double nuts on there(just have no clearance under there to eyeball the assembly)..being a bigun-has its disadvantages..lol

 

Car ramps will help you out with the clearance problems working under the truck. I just went through what you did about two months ago, although the ABS light had come on for me. It was the speed sensor in the rear diff. Once you take off the top nut, lift the brake line assembly and bracket off, you should be able to get to the second nut then. It might take a little wiggling to get the old sensor out, I think it has an O-ring on it that will make it stick.

 

be careful removing the sensor...i was a little too rough with mine, hence why i need a new one. dont pull it by the actual sensor, try to wiggle it back and forth from the actual body of the plug.