Hod hard is it, i have a dissassembled s4 LSD diff. that i need to install a brand new set of bearings. Thus, needing to set the backlash on the LSD and pinion. what tools are needed, how hard is it. If its out of my hands how much would a shop charge?

 

still need info on this, the FSM wasnt clear enough.

 

oy, you opened yourself a can of worms. You need shims, feeler gauges, paint and knowhow to do those right. If it's a little off, say goodbye to your hypoid gears. Not that it's impossible, but i'd rather rebuild my transmission with one arm than to try to tackle the diff.

*edit* and the FSM is probably your best bet when it comes to the specs and how to do it.

 

to mazda it goes LOL!

 

Find yourself a local performance tranny/diff guy. A guy around my area recommended by mazdatrix will rebuild my diff for 175 or 275 I think if I suppliy all the parts.

 

it really does take a touch of experience to work on diffs. almost every shop i worked at almost none of the techs would work on diffs and were always looking over my shoulder when i was building one, i had to shoo em off like flies. maybe cause the damn things stink like ***...

never touched a mazda 3rd member diff however but i probably wouldn't advise doing it if you don't feel comfortable with the measurements you are taking/getting from the diff. it can be pretty costly if you don't get the gears setup properly and it eats the ring and pinion or if you need to re-shim the pinion and keep destroying pinion bearings removing and shimming it.

there is no universal special tools for building a diff aside from a select few, to properly setup a diff you need all the tools specially made for that differential. after building so many you just get a feel for when things are loose/tight/just right so with enough experience you don't need many of the special tools.