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Rear diff question from a new guy

4502 Views 11 Replies 6 Participants Last post by  wasp919
I recently pulled off my rear diff cover on my 2000 silverado 4WD Z71 5.3 because of a clunking noise that was happening on take off. Local chevy dealer said it was a faulty transmissoin mount and that it was no big deal. I was not convinced so off came the rear diff. When i pulled it off the spider gears had chunks missing and the carrier pin and retaining pin had wear. The ring and pinion looked good. I have checked a couple forums and found other people with exploded rear ends at 40 - 70000 mine has 113000 so i guess im lucky its made it this far but i was wondering if it would be a good idea to put in a powertrax no slip diff or would i be better off with a locker or posi unit. I do not do much offroading it is mostly a daily driverand every thing is stock except 285-75 wheels and tires. any help would be appreciated thanx.
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Can't go wrong with a locker, they are alot better than GM's gov-lock
Do you have the Gov-lock (RPO code G80) carrier or an open carrier or other? If you decide to put a "lunchbox" locker (like the no-slip), you need to know which carrier you have. I believe that the lunchbox lockers are only made for open carriers, but you'd want to check that with the vendor/locker manufacturer. If you have a G80, your choices might be limted to replacing the spider gears etc. or some form of carrier replacement (at which point I don't know that a lunchbox locker makes sense).

Any chance you have a 14 bolt rear, or can we safely assume you have a 10 bolt?
I have a 10 bolt rear end and im pretty sure it is only an open diff only one tire drives i am not a rear end guy so im going on what i have been told bout my truck i actually called summits tech line and they recomended a eaton posi unit and they said that guys have been having problems with the stock carrier breaking fromm 99 and newer trucks.the eaton is the same price as the powertrax just a little more work.
You dont off road much and you have rear diff issues. I'd say rebuild the rear end and leave it open.
There's an old trick that works well when using an open diff off road, when you get stuck push the parking brake down a little while giving the vehicle gas, this switches the power from the wheel thats spinning to the other wheel that may have some traction. This can be done with the front wheels also by use of the gas and brake pedal at the same time.
im pretty sure it is only an open diff only one tire drives
IMO, that's not proof that you don't have a G80. My G80 used to allow one wheel peals all the time. I got a good feel for when mine would and wouldn't lock up. I've seen some reports from people who can't get their G80 to lock at all. Where there is already damage to the carrier internals, it's possible the locking mechanism is also damaged. Take 30 seconds and check the RPO sticker in your glove box to see if there's a G80 code there.

One of the weak points on the 10 bolt is the carrier, so I wouldn't be too surprised to see people reporting breaking the carrier when using a lunchbox locker.

Which Eaton posi is he suggesting? I would expect he is referring to the eaton clutch type limited slip, which is a decent unit and rebuildable (important with a clutch type LS so you can replace the clutches when they wear out). Just want to be sure, because Eaton makes lockers and other traction aids (including the stock G80 gov-lock). I personally don't like the term "posi" because too many people use it as a generic term for any differential traction aid (LS, locker or spool).

Assuming it's the Eaton LS, then, the part may be the same price as the lunchbox locker, but installation will likely be a lot more. Any time you replace the carrier, you have to set up the gears, which is a tedious task that adds to the cost. Usually you can install a lunchbox locker a lot easier than anything that replaces the carrier.

While we're talking about cost, if you have an open carrier, and the carrier itself is undamaged, it shouldn't be very expensive to replace just the spider gears. In terms of cost, that will be by far the cheapest option. But it all depends on what you really want to get out of this repair.
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Since you do not do much offroading I would suggest the posi unit that summit suggested rather than leave it open or lock it. the posi in the snow and mild offroading is phenomenal and i think a locker is overkill unless your offroading hard or in mud. Also Eaton makes great stuff. just my .02
i think that i am going with an eaton posi unit $469 at summit that way i wont have to mess with my rear end ever again. thanks for the help.however if anyone has a question on the trans mount i am going with an energy suspension trans mount and i will let you know if that solves my clunking on take off or if it is the rear end.
alright man keep us posted... and maybe post a few pics of the install of the posi rear?
Why the hell would you want to lock a DD?????????? Go buy an open carrier for $50.00 pay $200 to install (if you don't know how to set-up gears and call it a day!

DO NOT GET AN EATON /DETROIT/ POWERTRAX LUNCHBOX LOCKER -- If you are hellbent on going with a lunchbox locker, get an Aussie locker, they look the same as the powertrax but they don't break!
I bought an eaton posi unit, U-[joints and a trans mount i will be installing all this weekend and i will keep you all posted i will try to get pictures of the install but if i cant i will give you guys all the info on the install. My friends dad has been doing tranny's and rear ends for bout 30 years says it should be simple cause im not messin with the pinion so it should be a snap. thanks for the help.
The Eaton is in!!!

I got the eaton in with minimal difficulties i had a guy with 30 yrs of doin rear ends help and no problems. Factory put an extra .067 worth of shim i guess with a spreader but i did not use one to set up the eaton it is still tight though got .009 worth of backlash and everything is runnin top notch. The posi cured alot of my problems but still getting that damn clunking. I put in the new tranny mount but it is still there. I checked my shock bushings and they are worn (I can turn the shock in the mounts by hand) im gonna try replaceing them since they are in need of it and cheap i guess replacing worn bushings untill i find it is where im at sorry no pics but if anyone needs any advice i would be glad to help there is really nothing to it as long as your not replacing the pinion.

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