I've currently got the rear axle removed from my car (it started off as a much smaller job!), and wondered what the allowable amount of movement at the diff is (where it meets the prop shaft) - I can turn the diff about 1/3", with the wheel hubs stationary on the floor, there's no sideways movement or play in the bearing. Is 1/3" ok and normal? As far as I'm aware there was no knocking or nasty noises out on the road. I'd really like to avoid dismantling the diff / half shafts if possible, but if something needs replacing, now is the time to do it!
Sounds passable but I have come across a problem with modern spec ep oil. there is an additive which disolves the thrust washers in the diff! I ahd terrible problems with my GT6 same complaint. Ended up with a rebuild