OEM Posi/LSD Clutch kit?

Hey everyone. It's been a little over 7 years since I've posted a thread in this section. Normally I've been able to figure things out through my own research, but I'm coming up empty handed here. I notice now a significant decrease in site traffic here compared to what it used to be unfortunately, but the community here has always been very helpful, so i figured it's worth a shot. Here we go: Starting with specs - 1984 Caprice Classic with a 350 transplanted from a 1992 2500 Silverado (EFI, computer, serpentine belt layout and all) 700R4 tranny and a 7.5" 2.73 open rear end. I've recently scored a rear end that I plan to install into my Caprice. It's a 1981 7.5" 2.93 posi rear end. Before doing the swap, I want to go through it (wheel bearings, seals etc.) Currently the limited slip function is in working order, but I figured while I have everything apart, replacing the clutches/friction plates wouldn't be a bad idea. Where I'm coming up empty handed is finding a replacement clutch kit for it. Does anyone here know where I could find a kit for it, or what to look for?

You have a few things going against you. It's not a 3-series carrier, so parts are going to be more scarce. You might check with this place:

http://www.quickperformance.com/GM-75-7625-10-Bolt_c_78.html

However, behind a 350 and in a heavy-ish Caprice, you may want to consider swapping to a later 8½" 10-bolt with a locker. They are more durable, and a lot more plentiful. Something from 93-96 B- or D-body might just fit right in.

Thanks for the response! The link you posted has a great selection! I agree, and have been in the market for an 8.5" 10 bolt for quite some time. For some reason they're hard to come by in western NY setup for a 4-link suspension rather than a leaf spring suspension. On the occasion that I do find one, the seller normally wants $500+ for one in as-is condition. This 7.5 I got for $100, and its in seemingly great shape. (around here older parts like axles are normally severely pitted/rotted as salt is used heavily on the roads in the winter) Here's another (maybe seemingly stupid) question... I see the terms "duragrip" or "gov-loc" a lot... I know GM used the term "positraction" to describe their LSD's. Are the "duragrip" or "gov-loc" terms anything of significance? Also, I thought the carrier series only determined how close/far the ring gear flange was to the center of the axle to accommodate the smaller/larger pinion gear. Shouldn't the clutches theoretically be interchangeable amongst all 3 carrier sizes?

$500 for a used, as-is axle seems a bit steep. Geography may have something to do with that. We get plenty of salt in the upper midwest as well, and lately they have been also using lime chips as traction aid, just to make corrosion protection even more of a challenge. Many of the roads have had their first applications of "hot salt" (liquified) in late October, and that isn't likely to end until April.

Keep in mind that any axle from a '77 to '96 B-body should bolt in. Changing from a 7½ or 7-5/8" 10 bolt to the 8½" 10 bolt will require a shorter driveshaft (by about an inch) so buying the axle and shaft from a donor car may be advisable. Wagon axles will bolt in, but they are wider, so you may want to avoid those for a sedan unless you want to play with different wheel backspacing from front to rear (like my F-body).

If you get an Auburn style unit (cone clutches), the carrier will be important. These were more common in those earlier years, but could be found in F-bodies and B-bodies up to and through the mid-1990s. These will wear out simply from normal street use, so any used Auburn axle will likely need repair or adjustment, or at least a thorough inspection. It will also require a friction modifier additive in the oil or it will be noisy on turns and wear out even faster. The additive must meet the GM10582358 specification. CRC Sta-Lube (p/n SL2411) works for me.

If you get a plate clutch type (commonly called Eaton or Detroit locker), the plates, springs, and spacers may be more universal. A worn clutch pack can be repaired more easily than a cone type. These also wear out from normal use, and also require the friction modifier additive in the gear oil. These are more likely to be found in 12-bolt axles found in light trucks. These will also lock the two axles together at low vehicle speeds, much like the Saginaw gov-lock differential.

If you get a "gov-lock" unit it might not matter. The gov lock is a centrifugal locking pawl which pins the two axles together at a predetermined differential RPM, and they do not engage softly. They don't usually wear out, and instead they just break if hit too hard with torque. The gov-lock also does not require a friction modifier additive in the gear oil, whereas the other two types do. For normal daily driving this type is fairly reliable. They will lock the axles when traction conditions mandate it. They are not suitable for sport-type use since they do not withstand severe torque spikes very well, so if you are going to race or do burnouts in the Cappy this might not last. If you simply want traction in slippery conditions, this is a good alternative. They are commonly found in light trucks and vans, and on many sedans.

A fourth type is the torque sensing (Torson) differential. It uses helical gears to distribute driving force to the axles instead of clutches. These were used on many F-bodies from the mid-1990s onward. They require no friction modifier and essentially have no wear parts.

Great post Blue!!

If you think my post is good, you should see my gate.

Looks there is maybe 5 of us holding down the fort for the GM stuff, not like it was a few years back.

No, it isn't like it was several years ago. However, those quickie answers from robots on some of those Auto-helper and Ask-A-Mechanic sites and Facebook kinds of places leave a lot to be desired. I was approached by a couple of those sites a while back trying to recruit for their sites, for a whopping $5 per answer. The ONLY winners are them. I'll leave that to those "professionals" who are ASE certified in Tire Balance and Exterior Lighting System service.

I would go here http://www.impalassforum.com/vBulletin/34-engine-problems-maintenance

great info on b body GM vehicles many options to do on the drive train. LSD on these are not repairable . many use eaton locker truck diff 3.73 gears .also the 383cu / pcm power upgrade and manual shift etc/ etc...

Thanks for the responses guys!

$500 for a used, as-is axle seems a bit steep.
I agree, that's why I've been hesitant to buy one. I would entertain the option of buying an entire parts car to get one.

Keep in mind that any axle from a '77 to '96 B-body should bolt in. Changing from a 7½ or 7-5/8" 10 bolt to the 8½" 10 bolt will require a shorter driveshaft (by about an inch) so buying the axle and shaft from a donor car may be advisable. Wagon axles will bolt in, but they are wider, so you may want to avoid those for a sedan unless you want to play with different wheel backspacing from front to rear (like my F-body).

Again, I agree. I actually had a parts wagon with an open 8-1/2" 10 bolt but passed on keeping it for this reason exactly, along with the larger bolt pattern wheel hubs (not knowing at the time how to address this issue). In hindsight, saving the driveshaft, and front 5x5 hubs/brakes would have been a good idea for matching a future 8-1/2" swap.

If you think my post is good, you should see my gate.
Hahahaha