Rear End Question

[Already Gone]

I have an opportunity to buy a wrecked 2003 Chev pickup. It has the 4.8 and the rear end is a 3:42 with the G80 Limited Slip option. This is exactly the setup I want for my 72 and I'm wondering if it would be big deal to swap the rear end into my 72 knowing I'd have to get the saddles for the trailing arms welded on. I didn't look to see if it is a 10 or 12 bolt.

[colin_havens]

Shouldnt be an issue. Just be sure the axle width is within tolerances so as to not increase/decrease your track width in the rear too much and cause rubbing if you plan on running the same wheels. You may need to get new axle shafts though, as if Im not mistaken that axle is 6 lug instead of 5. Also make sure that the driveshaft will bolt up to that yoke.

If there is no issue with any of this, just cut off the old mounts with a torch, grind the axle tubes smooth, bolt it up and set your pinion angle and tack on the saddles. Be sure your axle is centered under the frame. DOUBLE CHECK YOUR PINION ANGLES BEFORE FULLY WELDING IT UP. If everything is all good, weld up the saddles, and change the differental fluid in the rear end as the heat from the welding and grinding can cause it to break down.

Swapping different axles into these trucks or any other vehicle has been done for decades. Should not be a hard swap, and could be done on a Saturday afternoon.

[passthebuck]

I _think_ G80 equals a Gov Lock. Googling G80 will save you a Gov lock headache.

[Cid636]

It's definitely not a 12bolt its been a long long time since those have ever been used, I think you will find it's an 8.6" 10bolt, similar housing to the older 8.5"diffs, with a locker(not limited slip). It will be about 4+ inches wider than your existing diff and will be 6 bolt wheels not 5 as already stated. Have you looked at it yet as I am thinking an 03 would be disc brakes also, that could add even more complications. And almost guaranteed to be some u-joint/driveshaft modification as well.

Its doable, its actually pretty much what I am going to do with my current project, but it's far from a bolt in deal.

[eagleuh1]

Don't forget the panhard bar bracket or mount needs to be added on.

[Already Gone]

Originally Posted by Cid636

It's definitely not a 12bolt its been a long long time since those have ever been used, I think you will find it's an 8.6" 10bolt, similar housing to the older 8.5"diffs, with a locker(not limited slip). It will be about 4+ inches wider than your existing diff and will be 6 bolt wheels not 5 as already stated. Have you looked at it yet as I am thinking an 03 would be disc brakes also, that could add even more complications. And almost guaranteed to be some u-joint/driveshaft modification as well.

Its doable, its actually pretty much what I am going to do with my current project, but it's far from a bolt in deal.

Thanks for the heads up. It sounds like its more than I can deal with. I called Currie in California and was quoted 2500.00 for a 12 bolt with 3:42's and a Eaton Tru-Trac. I know that would be a bolt in as well as being bullitt proof.

[cdowns]

go to local shop and check price to rebuild your present rear with posi and ratio of your choice

should b less than half of what a new rear will cost plus there wont b shipping and import fees

pretty sure from currie you'll still need to weld on the saddles and panhard brackt your self

[Already Gone]

Originally Posted by cdowns

go to local shop and check price to rebuild your present rear with posi and ratio of your choice

should b less than half of what a new rear will cost plus there wont b shipping and import fees

pretty sure from currie you'll still need to weld on the saddles and panhard brackt your self

Thanks for the heads up. I assumed ( but would have asked before I made the deal ) if the saddles and panhard bracket would be attached.

[LONGHAIR]

Originally Posted by Cid636

I think you will find it's an 8.6" 10bolt, similar housing to the older 8.5"diffs, with a locker(not limited slip).

Not likely. There has never been a "factory" equipped "locker" in any 10 bolt. They quit using true lockers (No Spin) with the end of the HO-52 type rear ends.

That "lock" word in the discription of the G-80 (Gov-Lock) is a huge mis-nomer. They are not a locking differential. It is a simple "clutch-type" posi unit that has a centrifugal "governor" that applies more pressure to the clutches...rather than the springs of the standard type posi.

[prostreetC-10]

AKA.....time bomb

[Cid636]

Originally Posted by LONGHAIR

Not likely. There has never been a "factory" equipped "locker" in any 10 bolt. They quit using true lockers (No Spin) with the end of the HO-52 type rear ends.

That "lock" word in the discription of the G-80 (Gov-Lock) is a huge mis-nomer. They are not a locking differential. It is a simple "clutch-type" posi unit that has a centrifugal "governor" that applies more pressure to the clutches...rather than the springs of the standard type posi.

Well, GM calls it a locking differential as well as Eaton who manufactures it and it does just that it "locks". Yes it does use clutches to achieve that(as does a manual transmission clutch that still locks together), and it does not work the same way as a 40+ year old locking diff but most modern parts work considerably different than the older stuff. I have a few of them and they definitely "lock" and they are not a simple posi unit, so I would call them a locking differential as does GM.