96 2500 Diff cover

Rogue Leader · April 16, 2012

Hey all, I know this question would be easy to answer by just crawling under my truck however the truck is at home and I need to order this part today. My diff cover is leaking BAD and I'd like to get one of those TA performance girdled ones. I would assume they are recommended here? I use the truck for mostly towing my race car and race junk, so over 5000 lbs of stuff. I'm pretty sure its a 14 bolt rear axle, but just wanted to confirm here that it is, and not a 12 bolt.

It is a 96 2500 GMC with the towing package, 8 lug, 4.10 rear gears. Any other recommendations? Need to fix it this weekend I have a long tow to New Hampshire in 3 weeks.

GMstrong · April 16, 2012

yes 14bolt sf.

Rogue Leader · April 20, 2012

Thanks for the help. The diff cover should be arriving today.

Now for my second issue. It says fill till it comes out of the factory fill hole. Problem is short of hiring king kong, that plug is NOT coming out. So how much gear oil should go in there, with the TA cover, anyone know?

00Silverado4x4 · April 20, 2012

As far as the plug, soak it down with PB Blaster or WD-40 for a couple of days. When I did mine it definitely took some effort to get the plug out. Once you do have it out, clean those threads out real good and put some antisieze on the threads (not in the diff) to prevent rusting up so bad.

How much fluid? The 1500s are around ~2 qts so if I were to take a guess...buy 3 quarts to put in it.

Rogue Leader · April 20, 2012

As far as the plug, soak it down with PB Blaster or WD-40 for a couple of days. When I did mine it definitely took some effort to get the plug out. Once you do have it out, clean those threads out real good and put some antisieze on the threads (not in the diff) to prevent rusting up so bad.

How much fluid? The 1500s are around ~2 qts so if I were to take a guess...buy 3 quarts to put in it.

We PB'd it for 2 days and it wasn't moving. I'm gonna try to throw a breaker bar on it but honestly its so rusty I'd imagine the hole will just strip before it comes out.

Hmm... I do have a 3/8's adaptor for my impact gun, maybe that will work.......

00Silverado4x4 · April 20, 2012

Just what I would of suggested next, impact. Just hit it easy at first. Don't hit it with too much torque on it to possibly round out the hole. Also take a wire brush and/or fine pointed scribe/screwdriver to the edge of the plug to help remove the crud. I'll take it the fluid has never been changed. Wouldn't surprise me, these trucks seem to go a long time on diff fluids.

Rogue Leader · April 20, 2012

Just what I would of suggested next, impact. Just hit it easy at first. Don't hit it with too much torque on it to possibly round out the hole. Also take a wire brush and/or fine pointed scribe/screwdriver to the edge of the plug to help remove the crud. I'll take it the fluid has never been changed. Wouldn't surprise me, these trucks seem to go a long time on diff fluids.

I hope its been changed, but at 207k miles that plug sure looks like it never moved....

Rogue Leader · April 22, 2012

So much for wasy.... 13 bolts came out no problem. The 14th bolt is destroyed and not coming out.

I gave up and am bringing it to my friends shop... hanging my head in defeat.

00Silverado4x4 · April 22, 2012

Sorry to hear it. Well you tried, that accounts for something at least. Kudos to you sir.

Rogue Leader · April 23, 2012

Sorry to hear it. Well you tried, that accounts for something at least. Kudos to you sir.

Thanks!

Any idea if this thing need LSD additive? I assumed it was not an LSD, its got the towing package and 4.10 gears.

00Silverado4x4 · April 23, 2012

I could be wrong but you will either have an open differential (not sure of RPO code) or a locking rear differential (RPO code: G80) from the factory so you will not need the additive.

Any Pro's to confirm my assumption?

Rogue Leader · April 23, 2012

I could be wrong but you will either have an open differential (not sure of RPO code) or a locking rear differential (RPO code: G80) from the factory so you will not need the additive.

Any Pro's to confirm my assumption?

Yes my sticker has code G80