Diff. side cover leak
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,056
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From: monroe city mo
Diff. side cover leak
I am going to be replacing the differential side cover that has the axle seal that leaks, i think driver side,tomorrow. I have never done this before,so i am looking for a how-to or tips on doing this. Any help will be appreciated.
Tech Contributor
Joined: May 2008
Posts: 2,843
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From: Howell Michigan
St. Jude Donor '09-'10-'11
Below you will find a write up that I did for one of the other forum members. Hope it helps you out.
No, I did not follow the write-up. They have you remove way more then what is really needed.
I raised the whole car up so the tires were about 10 inches off the floor. Removed the left rear tire, brake caliper, and set aside. I hang the unit forward leaving hose connected and hang from the metal around the fuel tank cover in the wheel well area. Use a punch or drift placed in the brake rotor cooling fin and allowing it to rest against the brake caliper bracket to keep the brake rotor from turning while removing the spindle nut. Next I pulled the tie rod from the knuckle; it takes an allen wrench to hold the stud while removing the retaining nut. Remove the wire clip to the wheel sensor and the cable from the parking brake lever and move out of the way. I stuffed mine like behind the left muffler area.
I then removed the upper control arm from the frame attachments by removing the two bolts that hold it. The upper control arm, knuckle, and brake rotor can be rotated forward and pushing the spindle to allow you to remove the shaft from the hub. I next got under the vehicle to allow me to pry the diff end of the output shaft from the diff case. At this point the shaft can be removed. Pull the drain plug one the bottom of the diff and drain it.
The next hard part for me was removing the trans to left side cover attachment nut and then the stud. I ended up using the double jam nut on the stud, but then I had to heat the cover where the stud is in order to get it out. Once the stud was out I removed the damper assemble that is held in place to the side cover by two bolts. I removed the bolts that retain the side cover and then found a place I could lightly pry to get it started out of the housing. The next challenge came when trying the remove the removed side cover from the vehicle. If it is tipped just right it will fit through the opening where the shaft pass the frame and into the wheel well. It is a very tight fit, but can be done.
I cleaned all the parts and replaced the shaft seal with a new one and put on a new o-ring on the side cover. I applied grease to the new seal, bearing and the shaft where it slides through the seal and rides on the bearing. You need to do this as this is the only lube the shaft, bearing and seal gets until the normal diff lube works it way to this area. I used Loctite 515 gasket eliminator on the diff case flange (not the o-ring area). Wormed the cover back through the shaft opening and reassembled everything using the proper toque values. Hope this helps a little.
One more thing that I thought about last night that might help make your shaft seal and cover seal replacement go a little easier. Once you have the differential side cover loose from the main case, rotate the cover’s top to the bottom by turning clockwise or counter clockwise. Then, pull the cover’s bottom edge out first towards the shaft opening. You want the side cover with the mounting flange pointed down towards the floor as you start it through the shaft opening into the wheel well area. The reason for doing the earlier clock rotation, there is a oil catch area cast into the inside of the side cover that will catch onto the spine shaft not allowing you to pull it free from the diff case unless it is first rotated. This also put the cover in the right orientation to worm it through the shaft opening to the wheel well.
Hope this all makes since. Let me know how you make out with the change.
I would HIGHLY recommend using the GM gasket eliminator or Loctite 515 gasket eliminator only! No RTV or silicone type sealants. This is a very important part of the leak fix. GM has a service bulletin about this. The diff will need about 1.8 qts of 75-90 synthetic oil with LS and GL-5 rating. I used Mobil 1 rear end dope for mine.
Eric D
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,056
Likes: 0
From: monroe city mo
Eric, just want to thank you for the how to. I followed your instructions and got the job done. The only problem i had was the stud,could not get it out. I was replacing the entire cover so i just took a cut off wheel and cut the stud off. Then it was a breeze.
Thanks again.
Thanks again.
