I recently had the same old ABS and Brake light come on, so after research on this website I figured it was the ABS speed sensor on the rear diff. I took my truck to the dealer and they replaced it with a new one. At first lights were out, then when I got about 5 miles down the road thesame lights came back on. I took it back and they pulled the new sensor and there was a cut across the bottom of it (they thought it might be from thereference ring) they went back and cleaned up the old one and it had the same thing. It was a thin groove cut neatlyon the bottom it also had some metal shavings and he said the diff oil was pretty dark.All the dealership recommended would be a teardown and check everything out (about 8 hours of labor) and most likely a rebuild of the rear end. Anyone have any ideas or heard ofanything like this.

Thanks

By the way
My truck is a 2000 1500 extendedcab 5.94wheel drive automatic with approx 103000 miles. Also I recently had another problem with the brakes being spongy and itended up being airthatjust needed bled, and have 1 wheel cylinder that needs replaced. I don't know if any of thatinfo is needed above butI just wanted to be thorough.

 

Bad working brake lights and a sensor shouldn't need a complete rebuild of a rearend. That sounds crazy to me. I'd fix the brake issue first.

 

The lights I am talking about are the indicator lights on the dash board. The brakes seem to be fine. I am mainly wondering what is cutting the speed sensor and what I can do about it??

 

The reason they suggested a rebuild had to be b/c of that line that was being cut into the sensor. I don't know to much about rears, but is it the trac-loc rear? And if it is, do you have a problem with it locking? Or perhaps any noticable differences in the rear? I wouldnt just send it off to be rebuilt, But i would suggest pulling the rear pan and cheking it all out.. Maybe you'll see somthin wrong with it.. and at the least, get some new fluid in there.