Project_Daily

Hey y'all,
I recently picked up a 3.43 rear end out of a 99 Z28 to swap into my 94 Firebird Formula. It's basically just the diff housing and gear carrier, all the accessories, brackets and axles have been removed. My plan is to swap everything it doesn't have from my current 2.73 Auburn diff into the new one. I already know ABS won't work because this was a 4 channel rear (no reluctor on gear carrier), but is there anything else I would have to pick up to make it fit that wouldn't already be in my car? From p/n s I've surmised that the carrier cross pin and bolt that locks in the axles swaps between the torsen and auburn carrier, can anyone confirm this? And finally, what are some relatively cheap longevity/wear items i can replace in this new rear end that won't require me taking it to a shop to reset the gear lash? Thanks for any help

FirstYrLS1Z

iTrader: (4)

The Auburns' pin is round, the Torsens' is a flat block referred to as a 'paddle'.
What is broken/wore out in the original as the reason you're doing this ?

Project_Daily

The cones in the Aurburn are completely trashed, the car only does one wheel peels. I also want to upgrade the gear ratio and i picked up the 3.43 rear for only $50.

FirstYrLS1Z

iTrader: (4)

3.42s' were issued with 6 speeds and manual transmissions are not 'kind' to the little GM 10 bolts. I would suspect the 99 rear was pulled apart to get the backing plates to use on a larger aftermarket rear. Are the carrier and ring//pinion still in the 99 rear intact OR 'loose parts' ? If intact the setting of the 'gears' should still be okay OR they could've been 'impacted' and be 'noisy'. It's always a 'roll of the dice' to go with a used 6 speed rear. Being that you would be using it in an automatic car, that would not make anything of the 99 rear worse.

Project_Daily

The ring and pinion are still installed, and the teeth on the ring gear look to be in pretty stellar shape actually; rotating the pinion by hand doesn't produce any excess noise. I'm not too concerned about blowing it up myself, im running the stock valvetrain in my car with a lot of bolt ons, and ive picked up a TA cover to install.

01ssreda4

iTrader: (96)

this wont end well..............

Project_Daily

Could you explain what you mean? The stock rear end has held up just fine thus far, 130k miles with no issues other than roasted clutches.

greg campbell

iTrader: (2)

I'm guessing 01ssA4 is implying that 10 bolts are not the toughest things to use. Make sure pinon preload is correct, set backlash correctly. I shoot for the middle, let's say spec is .006-.010" shoot for .008". Then check gear pattern once again shoot for middle of ring gear tooth. Vertical and horizontal. You may need to borrow a dial inch lb wrench if you don't have one but you can buy a dial indicator fairly reasonable with a magnetic stand. Plus you can use it for numerous other things automotive related. Don't run it unless everything does check out or it will not end well. That is my advice from the 6 ring and pinon changes I've done and all have worked flawlessly because these principles were followed to the nth degree.