gm truck rear end

[desbird]

did gm make a 12 bolt truck rear end if so do the gears inter change

 

[SSedan64]

Yes GM made one 64-82 but, they don't swap into the 65-72 Car 12-Bolt.
Used to be possible but, I don't know if the specialty Bearings are still made.
Truck Pinion gear Diameter is 1.438", Car Pinion Dia. is 1.625"

 

[desbird]

do you known who made the bearing and is that 1/2 ton trucks and what spline and now wide

 

[prairiehotrodder]

The gm truck 12 bolt is a tough rearend. I've beat the heck out of them and they still survive. Just don't use the gov-loc carrier. The axles are 30 spline and i think the side bearings interchange with the car 12 but not much else. One thing i like about the truck 12 is that lots of good gear ratio's are easy to find in junk yards. 3.73 is really common as well as 3.40 and 3.07 . I've cut up truck 12's and built them to fit camaro's but because of the cast center it would be tough to adapt them into a g-body unless you were converting to ladder bars.
brian

 

[SSedan64]

do you known who made the bearing and is that 1/2 ton trucks and what spline and now wide

I'm not sure who made the Bearings, probably Timken etc.. Takes some setup/shimming skills to do that kind of swap.
Tom's should know, Tom's Differentials - Home of MADE IN THE U.S.A.

Yes, 1/2 Ton Trucks/Vans.

They were much wider than car housings.
Axle lengths here, add Cross Shaft thickness for WMS to WMS width.

http://www.tomsdifferentials.com/2011catalog/Pages8-10.pdf

WMS = Wheel/Drum Mounting Surface.