Front bearings, rotors and Wheel speed sensors

[EraserX33]

Hello all,

I tried searching for this information but was unsuccessful. I am not sure if there is a post on it and if so just send me that way if anyone can.

Issue is with my ABS system. I need to change the wheel speed sensors for my front wheels. I am not sure how to do this. From what I can tell it looks like I am going to have to pull the rotor to get to them and it looks like it is more involved than just removing the brake caliper and sliding the rotor off. Is there a post or some instructions for this sitting somewhere? Can someone give me a quick guide on what to do (preferably in 3rd grade English) on what is involved and how? I truly would appreciate it.

Also… while I am in there, truck has 110k miles on it. I have never touched the bearings. Are they sealed, a hub unit that just gets swapped out, or can I clean pack and adjust? I need to get the rotors turned while I am doing this as I had a pad score one of my rotors last spring and I just replaced the pads once I seen that the rotors would be a lot of work to be removed.

Anyway, I sure would appreciate some guidance on this. Thanks ahead for all.

 

[bigdisneydaddy]

You may just need to clean the mounting surface that the ABS sensor sits on in order to get them working properly. The recall on the 99-03 models has the instructions for all the 1/2 and 3/4 ton.
In short... you will have to pull the caliper and its carrier in order to remove the rotor. On the top of the hub you will see a black plastic square with a socket head screw holding it down and a wire running to it. Lightly clean the area off and remove the screw, disconnect the first clip on the wiring harness so you will have a little slack in the cord. Gently twist the sensor in a clockwise/conterclockwise motion in order to free it. DO NOT twist it side to side or you will break the barrel of the sensor. Pull the sensor up and out of the hole and fish it through the hole in the shield so its out of the way, inspect it for cracks on the barrel, if its cracked it MUST be replaced.
Cut a 1"x2" piece of cloth and stuff it into the hole with a pair of needlenose pliers. With a wire wheel of brush, thoroughly clean the mounting surface to bare metal. GM recommends using 2 coats of a zinc rich primer over the surface, I suspect any good primer would work. Allow the area to dry. Make sure the sensor surface is clean and the sealing o-ring is still in place. Cover the mounting surface with a rust preventative grease and reinstall the sensor. You can test the sensor by disconnecting the harness at the upper control arm and checking the voltage of the sensor when the wheel is spun, IIRC it shoudl read 300ohms (doubel check that if you can) assuming the sensor is good you can put everything back together.

Hope that helps

Scott

 

[EraserX33]

Thanks for the reply. My rig is the classic C/K series, not the newer style. It is my understanding, (I certainly could be wrong) that the rotor will not come off without removal of the rest of the componants. Axle nut, spindle... etc

When I looked at it the other day the rotor was not removable without taking the entire assy apart.

Thank you
Darrell

 

[just a number]

you've got the one piece rotor and hub setup? i thought they quit making them before then. unfortunately if you do have the one piece, you'll have to take out the outer bearing and get ready for a heavy POS.

 

[SSduramax]

I would check the wheel bearings while you are down there. they are a sealed unit and come with the wires sticking out of them which i suppose is the sensor you are having issues with anyway.
So, if you have to take it all apart anyway and have a bad bearing.... they are prone to go out, I have replaced both sides on mine and only have about 70000 miles on it.
McRatt did a great write up on how to do it and you can find it
here
http://www.duramaxdiesels.com/forum/showthread.php?t=265&highlight=wheel+bearing
and here on this site too
http://www.dieseltowingresource.com/showthread.php?t=94