GM 2.5 ton axles

[Josh902]

Hey ive came accrost this site and have a question about axles i found these

what i think they are is GM 2.5 ton and im wondering what the strenght of them are? and if its worth it to put them under my mud truck? which is a 76 chev five 1/4 ton i know they are reverse rotation in the front and its workable with a normal transfer case but any info would be great on them generaly

thanks

 

[Oldfart]

The picture looks like a front axle under a GMC M211 series 2.5 ton truck. The differential ratio is 6.17 to 1. I am fairly new to these trucks as I just got mine in July. However, I think they would be tough enough for a rock crawler or mud bog rig (I assume you are starting with a 5/4 ton Chevy). That being said, they have two brake wheel cylinders in each drum. This "might" require more master cylinder stroke than the truck you want to modify has. I would assume you will be lifting your truck to accommodate the larger axles and tires which will cause the need to drop the transfer case or rotate the new axles so as to avoid u-joint bind or poor shaft angles that might fail under heavy power application. It is only my opinion, but the newer axles used on the M35 series deuces would probably work better. They are top loaded so the drive shafts can align better with the transfer case in a lifted application possibly avoiding axle rotation and/or dropping the transfer case. Single wheel cylinders are also cheaper to deal with and the axle parts (lockers etc.) are more current and available.

 

[Josh902]

thanks for the info. ide be going with rockwell toploaders if i could find a set around where i live but there as rare as a 8 legged dog. ive got a deal set on these gms for 300$ with all driveshafts so im going to buy them and see where it gets me lol. ive allready bought a 20inch lift for the ttruck and am buying tractor tires here soon for it also.

 

[4x4e350]

I have one of these GM axles under my 64 International, I had to cut out the center section, flip it 180 degrees, and weld it back on, not easy. The front axle is reverse rotating, so you either have to do what I did (not recommended) or run the front axle upside down. Or get a transfer case that is made to run the reverse rotating front axle.

 

[M543A2]

The GM axles are definitely not as tough as the Rockwells. I have twisted the axle shaft in the GM in normal farm service with a loaded truck in the mud in an M135 6x6. I have never damaged a Rockwell in the same to more severe conditions. We tried a test with a center punch once. We used it on the GM axle shaft and it put the customary center punch mark in it. We tried it on a Rockwell shaft and it flattened the end of the punch. Just a small demonstration of the hardness difference in the shafts. I also had the ball bearings on the GM pinion shaft fail where the Timken bearing Rockwells never have.

Regards Marti