Front Diff. Cracked Housing

[3500GMC]

I usually never re-use soaked linings, brake fluid, gear oil and stuff like this soaks into the lining. Makes for grabby gummed up brakes. Once the heat builds the soaked up stuff comes out.

It's common for the rear brakes to come on first. It's an OEM thing.

Once you pull the drums, see that the shoes are bottomed on the top pin. The top should not 'float' or come un-seated when you rock the shoes fore and aft at the bottom. If it does, it's either wheel cylinders or stuck e-brakes. Weak spring problems are rare, but some don't believe in replacing them, so they could be original to the truck.

 

[great white]

Pretty much.

Once a brake lining has been soaked in oil, it's ruined.

Replacement is called for and a good hit of brake Kleen on the drum surfaces.

Oil soaking makes them "grabby". Although, I can't say for certain that is your whole problem....

 

[23t]

I believe you both are right on "Replacing the shoes". I know better than to reuse the oil socked shoe. Learned that along time ago working on big trucks. Guess my thinking was that it would wear off, but they were pretty saturated with oil.

I will also check the pin like to said 3500GMC

Thanks guys!

 

[pat elliott]

Hi there new to this site. Great info! I also have a cracked front diff and was wondering if you guys could give me an idea as to how long swapping out the front diff assembly will take. I can still drive the truck the way it is now and cant be down for too long. I was going to go to pick and pull if they have the right gear ratio but wanted to bring the old one since they charge for a core. I am mechanically inclined and have air tools at home but wondering how long it will take me at the junk yard? Any input would be great! Thanks in advance!

 

[ak diesel driver]

I changed the one in my Tahoe in an easy couple of hours

 

[23t]

Hi Pat!! It was easier than I thought it would be. That "fear of the unknown" thing!!! LOL! But yes, a couple hours. Just remove the bolts on the axle shafts, remove the driveshaft, unplug the wiring, and remove the 4 bolts that hold the differential in place. Coming out wasn't bad but you may want a helper putting it back in. I did the job myself and gravity was working against me getting it back up in the frame.

I'll note on my deal here, my truck is a 97, my replacment was out of a 95. When the replacment was delivered, I noticed that the accuator and the plugs on the accuator were totally different from the 97. So to keep the 97 wiring and accuator original, I had to swap axle tubes. Other than that, everything else matched up.

Good luck with your project, other than not having air tools to use at the yard to remove your replacment, things should go pretty smooth with the swap.

 

[NVW]

With a broken housing they may not give anything for the core, you may want to ask them so you don't have to pull yours until you are ready.

 

[great white]

Core?

From a scrapyard?

First time I've heard of that.....

 

[bison]

Stuck e-brake cable.Shoes on one side installed backwards.

Adjuster wheel stuck on non-lockup side. (out of adjustment)

Return springs weak.

Make sure the wheel cylinder will retract/compress fully without sticking.

The second is my bet,sticky cylinder pistons,..cause...dirt/rust and grime in the cyl bore behind the dust cap.

 

[pat elliott]

Thank everyone for the quick response! Pick and pull wants $29 for the core we'll see if they take my junked one. Going there on Monday. Looks real basic, I'll let you guys know how it goes. Thanks Again!