JesseShredd

Looking to replace my 3.23 open 10 bolt. Found a 2001 zr2 s10 rear end for sale with low miles, disc brakes, posi, and 3.73 gears. Will it be a direct swap? If so, will I need to get 4th gen wheels to fit properly?

n1ffer

Does it have provisions for the torque arm?

AlkyIROC

The diff itself won't fit since the S10 uses leaf springs and the third gen is a torque arm/coil spring system. It's that torque arm mount that makes swapping over any other diff other than a third or fourth gen very difficult.

You do however have a bit of an advantage. Your 92 and the 2001 S10's diff will both use 28 spline axles but they're not the same length. You can pull the posi and gears out of the S10 and swap them directly into you diff.

As for fitting the disk brakes, they probably bolt to the diff differently so something would need to be modified or changed to swap them over.

Is it worth it? Depends on how cheap the diff is and what kind of condition the posi is in. They don't last forever and it's already 11 years old. If it's cheaper than buying a new posi and gears then pick it up and do the swap.

JesseShredd

Thanks for the confirmation. Think I'll pass on that particular deal. I am looking at costs of ring and pinion sets in my summit catalog, and I don't see any 28 spine pinions for a gm 10 bolt. With 28 spline axles, I need a 28 spline pinion, correct?

sofakingdom

iTrader: (1)

There are no 28 spline pinions.

The pinion in this model of rear has 27 splines.

The pinion does not care what splines the axles and side gears have. 2 totally separate matters.

JesseShredd

Thanks, that was I believed in the back if my head but wanted to make sure.

AlkyIROC

Spline count is only for the axle although some diffs can get larger pinions for more strength. Larger diameter means more splines are required. Things like a GM 12 bolt have 2 different models. Car and truck 12 bolts are not the same. The car version is actually stronger.

For your 7.5/7.625" 10 bolt, you already have 28 spline axles. 82-89 10 bolts only have 26 spline axles but can be upgraded to 28 spline with an axle and posi swap. Only third gen axles will fit into a third gen diff but there are much better aftermarket choices which will be much stronger than the OEM axles.

JesseShredd

I purchased a posi differential with a 41 spline ring. Going to buy a 11 spline pinion to covert to 3.73 gears. Will this be a direct replacement if I don't decide to get new bearings and shims...etc? unaware of which series it is at the moment, but will buy a series 2 to 3 conversion kit of needed.

big gear head

No, you can not do that. You can not use a ring gear from one gear set and a pinion gear from another gear set. Gears are mated at the factory and CAN NOT be mixed after that. You must get a mated set.

JesseShredd

Great to know! Thank you for clarifying that. Now, once I purchase a mated gear set, how does the direct installation process look if I don't decide to replace shims and bearings? Will replace seals if anything.

big gear head

You will be replacing the shims if you plan on installing the gears correctly. If you try using the same shims your pinion depth and backlash will not be set correctly and the gears will either make noise or they will make noise and fail quickly. The best thing to do is get a good installation kit with the gears and you will have all of the bearings, shims and other parts that you will need to install the gears correctly. It's cheaper to buy the kit instead of getting the parts individually. There is a pretty good thread on this sight that goes through the complete installation. Check the 10 bolt sticky and see if there is a link to it there.

JesseShredd

Sure thing, thanks big gear head!