How to replace leaking front axle seals?

01GMC4.8 · July 3, 2003

Don't you hate when everything happens after the extended warranty ends! I have about 53K on my 01 Sierra 4x4, and I noticed the front axle seals are leaking.

I don't know if this has been covered in previous topics, so please forgive if I am beating a dead horse.

Can these seals be replaced by someone in their driveway? Is it true that you just need to remove the outer drive train components, and push each axle in to the differential? I would like to try doing this myself to avoid the GM or Pep Boys garage prices. I don't have the manual yet, but I am going to start searching ebay for one.

If anybody has this procedure on front axle seal replacement could you please post it.

Thanks!

III · July 4, 2003

My 1998 Z71 has this same problem. I'll get a couple of drops per week on the driveway, but that's about it. My mechanic told me that this is a very common problem with all GM trucks/suvs. Why can't GM solve this problem? Some people have also told me that if I go ahead and replace the seals, that it will probably come back again. I know some people who have replaced their seals at least 2 times. I really don't know if I should fix it or just leave it. Chances are I'll fix it, but I don't like the idea of spending all that money and taking the chance of it leaking again.

Sorry this doesn't answer your original question 01gmc4.8, but I just wanted to write and let you know that you're not the only one with this problem.

01GMC4.8 · July 9, 2003

III,

I understand your concern that it may come back, but I just do not want to damage the front diff. with too little oil.

I had these same front axle seals replaced on my 94 K1500 Blazer twice in 175,000 miles. One of these times they replaced under warranty. I just wanted to try and replace them myself this time and save some money.

bigtruck21 · July 11, 2003

maybe this is why they put synthetic 75w90 in the back but not in the front(80w90)

frdfandc · July 13, 2003

The way you remove the front diff is to unbolt both half-shafts (the axles). Then you must disconnect the 2 or 3 electrical connectors. Then I think 4 bolts hold the diff in place. It is wise to use 2 people to for the removal & install since you have to wiggle the diff to get it in & out. (A 2nd set of hands is wise for the top bolt on the diff). When you go to remove the flanges that the half-shafts bolt to, you WILL need a BFH to pound them out of the diff housing. It takes some time, but its fairly simple. If I remember correctly, it took me approx 1 1/2 with air tools to replace both axle seals in a 97 Z-71.

96suburban1500 · September 12, 2003

Hi,

Wondered if you could provide a little more detail on how the seals themselves get replaced once you have the diff out of the truck. I'm curious about it now that mine is on the floor and I'm going to re-seal it.

Any help appreciated,

Dave

Jailkeeper · September 12, 2003

Whoa guys, why are you pulling the front diff. just to replace axle seals??

Click the link for Autozone's online manual - this is for a 97 K1500, it tells you how to remove the front axles.

http://www.autozone.com/servlet/UiBroker?F...23d80087c5f.jsp

96suburban1500 · September 12, 2003

Hi thanks for the reply and link.

My diff started grinding loudly in 2WD (esp. in turns) and would generally shutup in 4WD. Both sides output shaft seals were apparently leaking and I let the fluid go low for too long. I made my bed. From what I'v gathered so far it looks like it needs a rebuild, hence the removal from the truck.

So I need to gather more info on the details of disassembly of the unit and what to look for and replace inside.

From the link you sent, what I really need to know is where to start with respect to fig. 6 exploded view of the assembly.

Any other links with detailed front differential procedures or tips would help.

Thanks,

Dave

Jailkeeper · September 12, 2003

96Suburban1500 - if you are that involved in rebuilding your front diff let me suggest something without insulting you.

I don't know your mechanical abilities, but replacing bearings and gears in a diff. assembly requires considerable knowledge. You have to have the pinion preload just right and the right amount of backlash in the ring and pinion gears. If you aren't "capable" of doing this by yourself, you are wasting your time and most of all, lots of money. You would be better off taking the diff. to a qualified shop and have them do the work. Since you have already done the hard part (getting it out of the truck), it won't cost you an arm and leg to get it rebuilt. Plus, you'll probably get a warranty with it.

I've rebuilt several rear ends in pickups and semis - believe me when I say if you don't get everything just right you WILL have problems. Whether it's a high pitched whine or growling noises, the ring and pinion will not last very long. Good luck.

03Bluerado · September 12, 2003

96Suburban1500 - if you are that involved in rebuilding your front diff let me suggest something without insulting you.

I don't know your mechanical abilities, but replacing bearings and gears in a diff. assembly requires considerable knowledge. You have to have the pinion preload just right and the right amount of backlash in the ring and pinion gears. If you aren't "capable" of doing this by yourself, you are wasting your time and most of all, lots of money. You would be better off taking the diff. to a qualified shop and have them do the work. Since you have already done the hard part (getting it out of the truck), it won't cost you an arm and leg to get it rebuilt. Plus, you'll probably get a warranty with it.

I've rebuilt several rear ends in pickups and semis - believe me when I say if you don't get everything just right you WILL have problems. Whether it's a high pitched whine or growling noises, the ring and pinion will not last very long. Good luck.

Hey it sounds like you know what your doing and are pretty good with a wrench but like jailkeeper said there may be an easier route, I would look into a good used one on eBay or carpart.com or something, may save you some time and money! Good luck!