I just purchased my first jeep, an 01 Cherokee, 4.0, ATX, Dana 30 & 35, 3.55 gear ratio. One of first upgrades I’m going to make is the installation of a locker. From what I have been reading many of you have a rather low opinion of the Dana 35.
1. What are the most common failures with this rear axle?
2. Were there any c8.25 axles with ABS, has anyone added ABS to an c8.25
3. What are the best years, models for c8.25 donors, are there any external identifiers to distinguish a 27 spline from a 29 spline axle?

The 35 has weak axle tubes and axle shafts and a small ring gear. I was snapping alloy shafts almost every trip running 33s locked. The 97 and up 8.25 is the 29 spline version and was never had with ABS in a Cherokee. You would need someone to make custom shafts with tone rings to make the ABS work. A few aftermarket companies make 44s that work with ABS for Wranglers so you might be able to come up with something but it won't be cheap.

you have a better ABS system then the old bendix system but i still am against ABS if you see any type of offroading. it is just a thorn in your spine. also you have a low pinion dana 30 up front. if you really dont care about your ABS then go pick up a paired set of axles (dana 30 HP C8.25 29 spline) out of a 97+ 4 cylinder. they came with 4.10 gears.

Thanks for the info, it looks like i made a poor choice getting an 01.

I wouldnt say you made a poor choice, Just run it till it breaks and upgrade to better then stock.

My ring gear snapped.

You should always install new u-bolts with a diff swap, not sure about the DS.

The 35 drive shaft is a little longer than the 8.25 but if you have a lift it often doesn't matter.