for those of you who have done this swap i seek advice

i am swapping the open three series carier in my 84z28 for an auburn style 3 series limited slip, so my question is, my plan had been to just swap over the ring gear from the old carrier to the new limited slip and the install the richmond carrier bearings and ring gear bolts. then reinstall the origonal shims to get a basline backlash reading then adjust it form there, my question is should i shim the new posi tighter ( like maybe .010) because the bearings are new? of course i will check my gear pattern as well but hopefully i wont have to reset the pinion.

thanks

steve

 

If all you're changing is the open to a Posi,
You will be OK with the Pinion as it sits now.
Just do just what you are saying.
.009 to .010 is a good backlash, I'd always shot for the .010 on used gears.

Sounds like you are have everything already handled.

 

.010 is about the same in relationship to a 500 mile drive in a car. if you only swap the ring gear you won't touch the pinion or the shims. the carrier shims thickness can't be changed, only the arrangement or placement but not total thickness. i'd go for around .008 BL. check contact after you have BL set.

 

sweet that is what i thought just wanted to make sure should i measeure the shim pack on each side after removal( with like a micrometer or the like) and then reinstall the same thickness on each side using the new shims i got in the install kit. and 0.90 or .010 is the ideal correct......can't wait mmmmmmmmmmm traction is good!!!!!!

 

I have just installed a Auburn limited slip in my 91 RS with 4.10 gears. Your backlash should be around .008, but richmond gears say .008-.012 is fine. I wouldn't go any more than .010 backlash. Your pinion bearings will need to have around 20 to 25 inch pounds of preload. Also you will need to add .010 of preload shims to the carrier shims. Shim your carrier to get your correct backlash. Check the gear pattern. If all ok you will need to add .005 shim to each side of the carrier shim packs to preload the carrier bearings. The rotating preload of the entire assy with new bearings should be around 30 -35 inch pounds. Good luck. Auburn limited slips will give you traction but I just can't seem to let my tires hook up to tell.

 

well now im a little confused should i reuse the two big shims that were orginally in the rear end and then add .050 on each side once i get me back lash set properly... my back lash was about .010 to .012 so should i try and aim for that ??

 

well it is all done

when i resistalled the origonal shims with the new carrier the fit was a little loose and the backlash was at about .012 to .014 so i just added a .040 on the drivers side which effectivly preloaded the bearings and moved the ring gearinto the pinion, so after that i checked backlash and it was .008 to .010 so i thought that was pretty good checked my pattern it was ok slightly heel side on the drive side and slightly toe side on the coast side but perfect depth wise ..... test drove no noise and tons more traction so i drive it home about 10 miles on the highway 60mph checked the cover and it was warm to the touch maybe 100-120 if i had to guess

thanks ede for the help and everyone else to

 

to me hitting the numbers is way more improtant than what the contact pattern looks like. if the numbers are good and the pattern doesn't look totally off i'm happy.

 

those were my thoughts as well since the backlash was ok and the pattern was acceptable i figured i was ok.... i did find out that they are gm gears 3.73. ive got about 100 miles on it still no noise and man am i glad to have ditched the "one tire fire"