I have been looking for a heavy rear for my truck and especially since mine is singing. I found a brand new 2003 GMC 4500 rear axle assy. Anyone know what kind of rear it is? I go up Monday to look at it, measure it see if it will fit with some mods. The owner said it is larger than a Dana 120.

A new chassis was purchased for an ambulance but the body would not fit as the rear was 4 inches too narrow, so they put the rear from the old truck in the new one. This has been sitting for a while and I can get it for $1250. Almost too good to pass up unless it is 4:88 or something like that. Usually an ambulance is lower geared than that.

I have checked and a Ford F550 rear will bolt to the springs, imagone that. I have no idea if this one will mod to the truck yet. It has the big disk brakes and a speed sensor, 19.5 wheels, but no emergency brake. Now some more figuring...

 

She's gonna be a wierd looking beast with 19.5 rears and 16 fronts there haulin..
Gonna be a Freightgeneraldodge..

 

Just temporary, it will get adaptors for the 19.5 up front. I know the ford rear will work, not sure if the GM will or not.

 

Now I see exactly why your name is Haulin in Dixie! Might as well go for the Rockwell 2 1/2 tons!!! Or do you need the 5 tonners

 

A 5500 level rear will do what I need but I may consider the 22.5 instead of 19.5 depending on the bolt pattern I end up with and the rear spacing. That may offset a poor rear ratio. I am really satisfied with the 2000 rpm at 70 and would not want to go too much higher. I need to build it up to load a little heavier safely. I have the pulling power now.

 

Most of the HD rears in these trucks, Ford and Dodge at least, are Dana axles. That's why they will interchange. Hopefully you will see a name on the axle. You may be able to get some more specs, not necessarily the brand, but other info, if you have the VIN for that chassis, from the GMS web site. I saw lots of inof there, but no brand of the axles.
You have to hope it's a common axle that has calipers with praking brakes made into them available, otherwise, you'll be looking for some kind of tranny mounted parking brake drum.

Chris

 

Probably a Dana 135. 13.5" ring gear and 13,500 lb rating (at least in the Super Dutys). That's about all I know about 'em though...
Chris