FIYAPOWA said:
As far as autocross goes, I would think the smoothness of the operation would be more critical than brute strength. Where strength would come in is hard launches, shock loading/unloading etc. I have an 8.8 with the factory TracLock - and I finally fried the clutches after 7 years of autocrossing. $104 for the carbon fiber clutch rebuild kit, and I'm back on track. I also have a friend who burnt his up in about a year of autocross/open track events - about the same power level (400 rwhp ish), but he was running wider/stickier tires. I have a buddy with a ratcheting locker rear end in a Ford 9", and it has a tendency to lock up at low power levels - good if you want to rotate the car, but not so much for longer sweepers. I think the housing is less important than the selection of the differential type itself.
Good to hear. I just finished installing an 8.8' factory TracLok rear end in the Monster. With 2.73 gears it should be ready for autocross duty.
Curtis
UltimaDork
4/16/18 10:32 a.m.
Gearheadotaku said:
My understanding is that GM uses the code G80 as a generic RPO for locking or limited slip diff. Different vehicles get different units for different reasons. Trucks use a gov lock unit. This is the low speed crawl-out-of-a-mud-hole type. It won't engage at highway speeds and really isn't meant for performance driving. Camaro, V-Series Caddies, etc use clutch, torsen or active diffs suited for the track.
Please correct me if I'm wrong.
You are correct. G80 is a generic code for basically anything not open diff. Many trucks got the gov-lock, many full size cars got a cone-style LSD, many F-bodies got a clutch style, newer Y-bodies sometimes get a worm/torsen style.
I would say avoid any that are on/off like the gov lock or an aftermarket toothed detroit locker type. Could make for unpredictable things.
My Firebird has a 9 bolt Borg Warner diff with cone clutches. I was able to have the cones machined and the case a bit too. Added some shims and LSD is good to go. This process can only be done so many times before the parts get to weak. Can the 10 bolt cone types be done the same way?
In reply to Gearheadotaku :
Probably, but you can get clutch type diffs for 10-bolts cheap enough that it doesn't make sense to spend the money on repairing the old.
When the Gov-Lock died in Da Boss's truck, we just put an Eaton clutch pack diff in it. We were replacing the R&P anyway since the truck was from that era where GM or their supplier valued toughness over longevity and the gears would wear through the hardening after only 80k or so and all the metal in the oil would eat all the bearings.... and the truck had 150k on it. Basically everything was "done" and it got new everything that wasn't the actual rearend housing. I think we did also re-use the pinion flange after putting a Speedi-Sleeve on it.
In reply to SkinnyG :
I was recently considering the True Trac for my 99 GMC Z71 that has an open rear
