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Front differential options (used/rebuilt) and a review.

7K views 0 replies 1 participant last post by  AnthonyJ124 
#1 ·
I thought it'd be worthwhile to post up my experience here. I had a bad front diff that had a real awful whine when on the throttle and sometimes a rattle under deceleration. I bought the truck that way, so it wasn't a massive surprise that the diff had to come out.

Given GM doesn't offer this differential anymore- I shopped used, eBay, and junkyards and found very little in the way of confidence in a used diff. Prices ran $400-800 on used stuff, obviously more for known good units and found a few in need of pinion bearings for a little less. Junkyards regionally weren't interested in giving much of a warranty either.

I run my TBSS every day for work and can't really afford chancing another failure (who can really?), so I searched for rebuilt differentials and found limited supply, typically based on limited availability/demand of the 4.10 gears. There were really no local or regional shops in New England that had parts or were interested in the rebuild work. Provenforce sells the gears and cases, it gets a little pricey, but they have a good reputation and know our differentials. I ended up calling Zumbrota Bearing and Gear, Manual Transmissions, Differentials, Transfer Cases | ZBAG and they stock the 4.10 gears and cases as well, and they'll assemble and ship a rebuilt unit to order in a few days. It ended up at $850+ $150 shipping and carries a $350 core (return shipping included). I ordered on a Friday and had it the following Friday. The rebuilt box came packed excellent and the diff looked new, very clean and with new seals and paint.

The diff is in now and I have a few hundred miles on it with no issues. I had a shop install the diff, since that's really the one job on the truck I didn't want to do on my back in the garage, and I'm sure it would have taken me a good weekend to get it in right. I paid $900 for the install labor/fluids/oil pan gasket and have to say Lee Myles transmission was great to deal with, they were experienced in doing the TB diffs and got it done quick. They didn't even mind that I bought the parts.

Hopefully this post helps someone in the same situation. I searched the forum a lot and got tidbits of information here and there, but never found much in the way of success stories, only threads that started with "I need a diff" or "I have a front end whine" then they trailed off into the archives.

The only disclaimer I'll give is, make sure your diagnosis is the front diff if you're getting a whine. I had a very distinct noise when on the throttle that would go away when off the throttle. This could also be the rear pinion bearing or maybe something transmission related and there are lots of opinions out there. I put the truck up and spun the front wheels a lot and confirmed I was getting noise (metal to metal sounding) from the diff and I drained maybe half a quart of dark black fluid from the diff (there should be a full quart).

Good luck!
 
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