Well the sparkly brown fairy came last night bearing a set of 4.10s . Im gonna take the diff housing and gears to a shop but they don't usually deal with rovers and want me to bring all the parts needed to get everything installed, so that begs the question, what do i need to get for the re-gear? i know that i have to get new diff bearings but how many? i know that there are 4 bearings to one diff, so does that mean i need two kits? shims?

 

Call Justin at Lucky8. I tried pricing crap out individually but it was easier and about the same price to go with Justin.
You need:
-2 Bearing kits(4 bearings/kit/diff)
-1 Shim kit(this along with the shims already in your diffs should be sufficient for two diffs
-2 Pinion bolts(1 per diff) or nuts, depending on your pinion gear
-2 Pinion seals(1 per diff)
-Since you're in there I would replace the crown(ring) bolts. I got mine (20 total I think) from RovahFarm because Justin was actually higher on these.
-I'd go ahead and replace the carrier bearing bolts too, 8 total(4 per diff)

Make sure these guys know what they're doing. Rover diffs use shims not crush sleeves so there's a fair amount of trial and error to get everything dialed in. They should be using setup races and the old pinion bolt to get it setup. Then when they get it dialed in, pull the setup races and install the good races and finish with the new pinion bolt. They'll also need all the torque specs. As Ian found out over-torquing the pinion bolt can make for a bad day.
Most of the important info can be found(not terribly easily though) on Ashcroft's website and in the RAVE.
Towards the bottom of the page they have some torque specs. http://www.ashcroft-transmissions.co...-4-12-r-p.html
Make sure they don't mix up the front with the rear. The new front gears should be reverse cut.

 

Thank you very much for your informative reply. What about gbr? Are they any good to get the rebuild kits from?

 

I'm sure they are. Bill is a good guy and will take time to talk to you and answer any questions. Not that Justin isn't, but Bill's focus is on diffs and driveline where Justin is a little more all encompassing.

 

Actually over torquing the pinion bolt is only bad if you break the bolt off(been there, got the t-shirt). With a solid Spacer once everything is set it can't move. When I had my rear setup the guy who set it up, who is regarded as the best in my area said the best way to torque the pinion bolt with a solid Spacer was "tighten the **** out of it, you don't want it coming apart!"

 

Bill will take lots of time to talk to you! Very nice guy and very chatty.

 

Gonna make me think this early in the morning, huh Ian?
It's been a while but isn't the pinion preloaded set with the small shims and wouldn't over-torquing the pinion bolt/nut adversely effect the preload?
When I was setting pinion preload and playing with shims I used a non-threadlocked bolt and would torque it to spec each time. IMO it's a good idea to always torque the pinion bolt(and other bolts) to spec each time to keep the number of variables down.

 

Well in theory if the shims are the right size they can only compress to X thickness no matter the torque. One of those things I never thought about but I trust the guy that's retired from Richmond Gear and has been doing ring and pinions for 35 years. He was thorough enough to surface grind a shim the thickness he wanted because he couldn't get it out of stacking them...

 

Over torquing puts undue stress somewhere. Whether it's over compression or stretching the threads it's probably better to torque to spec and use LocTite the final time. If under torquing would out not enough preload then over torquing might put too much, IDK.

 

Mine is set up with red loctite and tightened with impact. No loctite until proper preload set. I also use a 12.9 flange head bolt.