I am pretty sure my truck(gmc 5500) doesnt have a rear locker, I dont have a switch and got stuck very easily the other day.When I bought the truck I told the salesman i wanted one, but didnt make sure.I have the single 40gal tank,read somwhere that is a problem with the factory locker.Are there any aftermarket lockers for the 5500?

I am pretty sure my truck(gmc 5500) doesnt have a rear locker, I dont have a switch and got stuck very easily the other day.When I bought the truck I told the salesman i wanted one, but didnt make sure.I have the single 40gal tank,read somwhere that is a problem with the factory locker.Are there any aftermarket lockers for the 5500?
Do you have air? You could put an air locker in(uses air to lock the rear end up.

The G80 Limited slip diff. is standard on the C-5500 4x4, but on the 2x4 it is a $340 option.

Go back and talk to the dealer. If it was documenmted anywhere that you wanted the locker (limited slip) then the Sales Manager may be willing to work out something with you. At one time Eaton had a program where they would swap differentials to change to a different ration or to the limited slip for a reasonable price. The kicker is that it had to be done when the truck was brand new (like before it left the dealer).

is the large list i got with the truck the build sheet? I have a g-80 on the sheet.I really would like a true locker.I do have tha factory air.

The list you refer to is probably the broadcast sheet that gives all of the production part numbers and a description of them. If the G80 limited slip is on there then you should have it.

I would recommend against a true Detroit Locker as you have no control over whether it is locked or not and I've seen a lot of them break in tight turns on hard ground. Ideally if you could find a air locker that would fit, it would be the way to go.

What rear ends do the 5500's have?

What rear ends do the 5500's have?

there are 3 available for the 5500 if i remember correct .
they are all dana spicer's the s110 (13,500#), s130 (15,000#) and 19060s (19,000#)
I think those are the correct ones for the 5500 I am going off the top of my head someone correct me if i am wrong.

Nope, you hit it on the head. Those are the 3 they offer. The S110, 13,500# is standard.

what rear is in a '03 6500? would like to look into a locker for this thing. even with good tires the traction sucks from time to time