Rather than rely on old, worn diff backlash, why not set everything to factory specs? If it was worn with excessive backlash why would you want to mimic that?
I was wondering the same, and that makes total sense.
Once I get the dial gauge if the backlash is way out, or the pattern shows alot of wear or if there is damage I haven't been able to see I will just have to bite the bullet and replace the ring and pinion.
Even if I have to pay someone else to do that I'm still no further behind than I am now and I'm learning a huge amount so I don't mind.
So I just got back my 80 8.5" from the guy I've used many times to rebuild my rear ends. I also used a Tru Trac with 30 splines. Yes I had to buy new axles from Moser. The owner of the shop that did the work me always likes to use shims to dial in the pinion pre-load in lieu of a crush sleeve. His opinion is that if you are putting some serious hp to the ground the sleeve could move around increasing clearance.
My .02 on the gears is just get new ones. I like Motive Gear.
Thanks 73z I didn't know shims were an option instead of a crush sleeve, interesting.
My OCD says replace everything but the ring and pinion will be the difference between me doing the work or the shop so I'm treating that as a last resort.
I looked into upgrading to 30 spline but figured the stock axles should be ok to get me going and I can always change them for aftermarket 28's later. I'm not pushing loads of power and don't plan on putting slicks on, will hopefully hold up ok for the occasional smoke show
Your axles are probably worn from many years of use and need to be replaced anyway. 30 spline axles are just a little more than stock replacements and much stronger.
Good for you going for it and doing the work yourself man.
When the guy setup my rear he took it back apart and machined a solid sleeve the same length as the crush sleeve so it cannot change.
He is a professional welder and welded my axle tubes to the pumpkin with the correct nichol content rods and preheated it all to correct temp before welding and after that wrapped center in heat shield blankets so it cooled down slowly.