Differential CASE differences?

[TEGGSRB18C1]

Hey guys, I am looking to build a diff for my SS from scratch. The goal is to drop my OEM diff out, set it to the side and install a completely new built unit in with little to no downtime.

So, I found a BNIB V6 auto 2.92 diff for $100. All I care about is the case, the internals mean nothing to me. I'll be installing a TrueTrac, 3.91's with all new AAM bearings and seals.

I've poked around a little bit and there seems to be some conflicting information. Some posts on here state that the ring gear in the 2.92 is smaller, so, in turn the case is smaller. I have a hard time believing that GM would contract AAM to make an entirely different cast for V6 auto cars but I could be wrong.

Anyone have any first hand experience with this? I've looked at pictures, they look exactly the same as a manual V6/V8 diff. Thanks in advance!!

[CamaroCracka]

I've been on here since 2009 and this is the first time I have seen this one. The carriers are definitely different, so I'm not sure GM would put them in the same case, but it's possible. I would think the internal machining would have to be different. You could jack the car up and compare the rear covers. That might tell you if the cases are the same externally. Hopefully, someone who has rebuilt the V6 auto diff will chime in but the question from V6 auto guys is usually can I put a 3.27 diff in.

[ABM2SS]

The castings may be the same, but there may be differences in the machining. If that is true, there may be stamped part numbers on the housings to differentiate them.

[TEGGSRB18C1]

Thank you gentlemen, after closer examination side by side you can see there are slight differences between the 2 cases. The main difference or easiest to spot is the raised area I circled. Unfortunately, this is not a viable option for a doner.

I want to leave this thread up in case others stumble upon it and hope it helps.

[spyderbuddy]

I do know all the internals are different. The V6 Autos were completly different, Drive Shaft, Half Shafts And even the hub Assemblies are different, now for as the housing, I dont know.

The V6 Stick Shift was the same as the V8 Differential, The Hold rear end could be taken out of a V8 and swap with a V6 or visa Versa

[FasNuf]

I'll research some, but the manual says there are only 3 housings and 1 of those is the cast iron ZL1 so that leaves these 2. I cant read the label on your picture. I'll post what else I see.

[FasNuf]

250mm is ZL1
218mm is SS
218mm is also Z/28 but is always listed separate when it discusses specs
195mm has 3 top bolts on the rear cover like the new one shown, the 218mm only has 2 bolts.

[FasNuf]

These bolts.

[spyderbuddy]

good going fasnuf there is a differance

[TEGGSRB18C1]

Originally Posted by FasNuf

250mm is ZL1
218mm is SS
218mm is also Z/28 but is always listed separate when it discusses specs
195mm has 3 top bolts on the rear cover like the new one shown, the 218mm only has 2 bolts.

Thank you! This is exactly what I needed to see. Love the YT channel btw, been subbed for a while.

I'll narrow my search down to 218mm only. I really need to pick up those service manual books too, I hate chasing down torque specs online and then second guessing them.

[FasNuf]

Thanks guys. I think I've heard some say the factory manuals are on CD at a lower price. The 5 volumes in paper were over $500 if I remember right so not cheap.

I thought it was strange that the manual didn't say that the 195mm was used in the V6 so I can't be positive that's what it's used in, but it would seem so.