I've been looking for a while now to put either a Detroit truetrac or an ARB full locker on the back of my truck. The issue stopping me to date has been the $$, costs between $650 and $1000. Just yesterday i thought I check out the local wrecking yard and found this. It looks like a factory either limited slip or locker and I found it on a 2004 GMC Sierra 2500HD. Now I've read tons about Dodge and GMC/Chev having the same 11.5 AAM but can anyone tell me what did I just purchase. Is it a limited slip, a locker type like the Detroit truetrac or something else? I paid $75, did I throw my money away?

I don't do any heavy off road wheeling, just occasional trip to the local sand pits and bombing around in the deep Canadian snow.

JR

 

It's called a GovLock or G-lock, i can't remember exactly. Theres a set of weights that are moved centripetally to lock the diff. It's pretty much a true locker in my opinion and is a lot better than the limited slip in our trucks, as long as you don't overpower it.

Pretty good deal if you ask me. Are you planning on installing it yourself? Please post some pics if you do.

Let me know how it works out.

 

I was hoping to throw it in next week-end, depending on the weather. I'll take some pictures of the install for everyone. Pulling it out was actually pretty easy as the toughest part was undoing the 14 cover bolts and getting enough leverage on the main cap bolts to break them loose as I was laying on my side under the truck.
I did my 4.10's two years ago with a help of a buddy who had an extra shim kit so this should be a walk in the park.

So, what's the verdict? Should I throw this thing into my truck or sell it on E-bay and hold out for a Detroit or an ARB?

JR

 

Just out of curiosity how much power does it take to overpower it? I've heard that's the problem with the stock Dodge limited slip, they just get overpowered.

 

I'd have no issue using it. I do a fair amount of wheeling in my truck and have been looking for one of these to replace that poor excuse for a LSD that came in my truck.

They will take a lot of abuse. GM has been using them since the 70's.

 

The problem is when they let go the have tendancy to take out the ring and pinion. I've seen this happen once and it wasn't pretty. But that was in a purpose built mud truck with 44's and a driver that was more interested in putting on a good show than trying to protect his investment!

 

Personally I think the Gov loc's suck ... I would look at a Eaton posi , there a lot stronger and can be rebuilt with new clutches if need be .

 

Thanks for all the comments guys, however keep in mind this unit only cost me $75, and it'll cost me nothing to install. So my question is, should I install it in my truck or sell it hoping to get an extra couple of $$ for it?

Right now my truck has an oper diff, so anything is better.

JR

 

I'd install it and enjoy it. I've got a number of Duramax friends with these units and not one of them has complained of failure.

 

GM has been using the Gov-Loc in their AAM 11.5" rear ends since 2001. That is A LOT of trucks on the road. Normal everyday driving they hold up fine. Bigger tires and off roading could kill it quickly. If it let's go the damage is usually a lot more extensive.

 

I wouldn't put that behind a Cummins. They are weak in my opinion. They are designed so that the governor will prevent lock up at a certain speed, but they rarely function as designed resulting in failure.

If you can get it to lock before you put a lot of power to it you can make it last, knowing if it is locked or not is not always easy.

 

For sand/snow use I prefer the Dodge OE LSD to the Gov-Locks I have used before. They do take a little differnt driving style if your stopped thou..

But if your currently open and need something you got a good deal, but I'd rather have a ARB than a Gov-Lock.

I guess the Gov-Lock's I have used have never impressed me enough to spend any money on them.

 

if one has it use it til it breaks BUT dont replace it with same anything out there is better than that piece of junk.

 

We call them Gov-Bombs in the drivetrain industry. I take those POS's out and put either the Trac-rite for someone on a budget of the Truetrac for a few more $'s.

Unless you drive like an absolute grandpa and have a stock truck, don't install that thing!

 

I've got a limited-slip in my 06 GMC 2500 6.0 that works great. Don't know if that's the same one as you have. One of the better limited-slips I've ever seen if it is. I don't know how that'll hold up behind the Cummins though.