Front Differential Rebuild

[eric.dally]

Alright guys I have been searching the internet for hours now and can't seem to find what I am looking for. I am currently rebuilding my front diff on my 03 SS, trying to get rid of the famous front end growl and I have the diff removed from the truck but can't get the axle shafts removed from the diff.

 

I know that they don't have C-clips like the rear diff that would be holding the shafts in, but I can't figure out how to get the axles out. For you guys that have done this before how did you get the axle shafts out of the housing?

[eric.dally]

anybody?

[eric.dally]

Alright I did some more research and it seems that I just need to use a big slide hammer and they should pop free. Does anybody know for sure?

 

And where can I get the adjustor locks for the carrier adjustors, I know where I can get the rest of the bearings and seal for teh rebuld but haven't seen these listed anywhere?

[Krambo]

Sorry I can't help however I am suscribed to your post. Please update as you go along! Pics are also helpful...

[eric.dally]

I got it almost all the way torn apart yesterday, it turns out if you use a slide hammer the axles pop out quite easily. Once the axles were out I removed the passenger side axle housing and removed all of the bolts to split the case. Splitting the case proved to be the most difficult step so far as the dowel pins had corroded and it took quite a bit of force and a little help from heating the case with the torch to get them free.

 

Once split the carrier is loose as the two case halves are what actually hold it in place. I removed the diff and started inspecting the bearings and races, I found that the passenger side bearing and race were badly pitted but the driver side was in pretty good shape. I'm assuming the passenger side bearing is under more stress when driving as this is the ring gear side.

 

Next step will be to remove the pinion and inspect those bearings. I didn't have the correct socket so that will have to wait until tonight. Then I will just be waiting on part to show up. The kit I ordered comes with both carrier bearings and races, both pinion bearings and races, the crush sleeve, yoke nut, and stuff to mark the ring gear to see the pattern. If anybody has any input this teardown, can think of anything else I will need please feel free to comment.

 

Here is a link to the pic I have taken so far:

Front diff disassembly

 

Hopefully the link works, and I will continue to update it as the project continues.

[Krambo]

Yep your link works fine. This pic is my favorite. The bearing is shot!

 

 

Now, how did the fluid look when you drained it???

[eric.dally]

Now, how did the fluid look when you drained it???

 

The fluid actually didn't look as bad as I expected, it was a pretty dark but only had a small hint of metalic color to it. There were also some fine shavings on the magnet of the drian plug too. Compared to what other I have read that other people posted I expected much worse especially with how bad the sound was when I would turn. Looking at the ring and pinion gears I think I caught it in time it didn't damage the gear set.

[eric.dally]

Only a little more progress the last couple of days, I found out that it is pretty much impossible to remove carrier bearing with a cheap @$$ two finger bearing puller and managed to break one of the fingers off, oh well. Decided to get out the dremel and cut into the races being very careful not to cut too deep. Then hit it with a chisel and they split right down the side. Now I'm just waiting for the new bearings and I should be ready for reassembly.

 

I haven't really had any responses to the questions I've had in this post but I am mostly doing it because I read a lot about people having different noise issues with the front diff but there isn't much information about actually fixing the diff. I like to think I have pretty good mechanical ability but I had never rebuilt a diff before so this is a learning experience for me and hopefully someday if someone else gets fed up with listening to their front end growl some of this post is usefull for them too.

[BlownFogger540]

Yep your link works fine. This pic is my favorite. The bearing is shot!

 

 

Now, how did the fluid look when you drained it???

 

 

looks like mine did at 35k Lol

[eric.dally]

The parts finally showed up and I had time to work on it but the camera was dead so I didn't get any more pics. Anyways it was pretty easy, I pressed the new beaerings on the carrier and painted a few of the teeth on the ring gear with the paint that came with the rebuild kit.

 

I put the carrier in the case assembled the halves to checked the pattern on the teeth, and that looked good. So I checked the backlash and preload, and found both within spec. So I pulled it back apart cleaned everything again, put some silicone on the mating surfaces, torqued everything up, and put it back in the truck.

 

Got to take it for a short ride but it sounds much quiter than it did before.

 

Now I just need to replace the bearing on the output shaft of the t-case and the truck should be 100% again. I feel like there is always something that needs to be fixed. Oh well, at least its cold and crappy out side so I don't really have anything better to do.

[rojo_143]

Where did you order all of parts through and how much did they run ya if you don't mind me askin?? I might be doing this here pretty soon.

[eric.dally]

Where did you order all of parts through and how much did they run ya if you don't mind me askin?? I might be doing this here pretty soon.

 

 

I ordered them from completeoffroad.com, the entire kit was $130 and it came with everything that is needed for the rebuild. The item number on there site is Y GM8.25IFS-B.

[rojo_143]

As far as difficulty how hard would you say it is to rebuild?? i have never messed wtih differentials but i am very mechanically inclined. the only thing that worries me is if I would have to set the backlash or shim it. But with a decent set of directions i belive it would be something I would be able to do and save my self the 800+ in labor.

[eric.dally]

Personally I did not think it was that difficult and this was the first differential I had ever rebuilt. You can find a little info about this diff on line if you just do a google search for GM8.25 IFS rebuilds, it is the same as the 4x4 unit except on the passenger side we have a solid axle shaft from the carrier to the CV shaft and on the 4x4 they have an unlocking mechnism in the middle of the axle shaft. The carriers are the same

 

Here a couple pointers from my experience and info I found:

If your ring and pinion gear are still in good shape and you are going to reuse them it is unlikely that you will need to adjust the shims for the pinion depth. You still will want to check it though to make sure it has the correct depth by using the paint in the kit and painting a few of the ring gear teeth.

 

To measure the backlash put the case halves together and tighten the bolts then take the measurement on the yoke on the pinion shaft, and then divide this measurement in half and that should be your backlash. From the research that I did this seemed to be the most accepted way of measuring backlash on these units.

 

If your backlash or preload needs to be adjusted there are no shims in these diffs. You can see the adjustors in some of the pictures I attached above. If you screw the drivers side in and the passenger side out it will shift the carrier to the passenger side and vise versa for the other way. If you just tighten one but don't move the other this will increase your preload. If you have the special spanner wrench you may be able to adjust these without taking the case halves back apart but if you don't it will be much easier to move the adjustors if you take the case back apart so they are not loaded. My suggestion is that you check the backlash and preload before adjusting anything because mine was within spec so I didn't have to adjust them at all. If you do have to adjust them I suggest replacing the bendable locking tab as bending it multiple times will likely cause it to fatigue and break.

 

Good luck if you try and rebuild it and let us know how it goes.

[misterp]

Thanks for the posts here and the link to the rebuild kit; I just might rebuild my extra front diff on my own - the one in my truck is *very* noisy when cold and the noise goes away when the gear lube finally warms up after about 15-miles, the truck is starting to sound like an old tractor! So I think it's time for servicing!

 

Mr. P.