Differential Question

[engineeradam]

I would like to upgrade my differential and axle. Any tips. I have a 1987 GMC 6.2 4x4 no hanger bearing 1/2 ton with 10 bolt rear end. I don t know the gear ratio but I don't want to screw it up. I like the 12bolt, and what about a 1ton. but is the wheelbase different. I dont know much about diffs I ve only replaced a couple.

[DmaxMaverick]

On my '85, I replaced the OEM 10 bolt with a '78 12 bolt. The axle was a direct-fit bolt on, brake back plates and all. I did replace the diff (Auburn) and axle shafts, but the housing wasn't modified. Got tired of rebuilding/replacing the disposable 10 bolt. Not a whimper out of the 12 bolt, over a couple hundred thousand miles. The only accommodation I made was the U-joint. The pinion yoke was a different size, but an off-the-shelf joint made it simple. $100 for the pinion replacement (and loss of a full day) was no brainer compared to the $10 U-joint. Also, I changed the gear ratio to 4.10, from 3.73 (to accommodate 33"+ tires).

Upgrading to a high capacity axle (like a 1 ton) will require some significant modification.

[engineeradam]

thx, ill look for a twelve bolt then, its on my plow truck so i don't want that weak ten bolt. my buddy snapped three axles in two weeks on a ten bolt diff, before we switched it to a twelve.