i had some problems with them in the 8.8 ford applications.
the customer support is outstanding. this was years ago, but after they looked at the unit i wrecked, they called me(this is a unit just past the warranty period btw)and offered any locker they had. i had a 28 spline, and after hashing it out...and due to the fact i had the gears etc i went with a 31 spline 8.8. wrecked that too. and had various other odd failures.
they were steering me towards a 9 in or 60 after the initial inspection from their engineering guys of the unit i fawked up originally and really pushed it after killing the 31 spline and i regret not doing a 60 as it was the proper choice...i just did not have the loot to do wheels gears etc. and stayed with the easiest choice at the time.
so i fawked myself.
arb is not my first choice for a 60 rear, but likely will be what ends up in the front 60 eventually as they just have top of the line support. the product i was having troubles with surpassed all that was normal for one....i just loaded the axle too much and case/housing deflection was likely the main issue. my fault not arb's.
listen to them and consider you investment dollars carefully if your on a tight budget. sometimes it is better to wait and save some more upgrade then try to make something work that is marginal.
another thanks for arb.