speed_demon24

iTrader: (6)

First time doing a gear install from scratch. They are motive performance 4.10's. Backlash is .006 which is what is etched on the ring gear, and the pinion shim is .035". Old set had .028 shims in it and the pinion depth on the new pinion was .007" shallower so I figured .035" would be a good starting point.

Drive



Coast

99ws6ls1

looks like coast side could go a little deeper. this is just how mine looked when i did my motive 3.90 install. i left it that way becuase it was already the fourth time i had it out. it whines a little during very light throttle coast and decel but not bad at all. up to you. could try a few thousands thicker pinion shim and see where it puts you.

bww3588

iTrader: (49)

i like it, i would go with about .004 on the backlash to move the pattern in just a little bit, but otherwise looks good.

01ssreda4

iTrader: (96)

Looks pretty good to me. I usually set my Motive's up to .007 with a mock-up bearing, and when I do a final install with a new bearing it tightens it up by .001.

96lt4c4

iTrader: (5)

Looks pretty good to me, pinion could go in maybe .001-.002 but I think its fine.

speed_demon24

iTrader: (6)

Finished it up and took it for a drive yesterday. Gears are pretty much silent with a very faint hint of whine off the gas at 70mph indicated speed (speedo is still calibrated for 3.73's). The drive stayed pretty much in the same place but the coasted centered up a bit after I put on new bearings and set the pre-load with the solid pinion spacer. I also had to move the carrier .002" away from the pinion to keep the .006" backlash. Overall I'm happy with it.

One more thing worth mentioning is how much thinner the metal thickness of the napa crush sleeve I had in there was compared to the ratech one in the install kit. I still used a solid spacer, but it ended up .010" thicker than the crush sleeve I took out.

96lt4c4

iTrader: (5)

Good deal. Its funny because the Motive instructions call for .008 to .012 back lash, yet the gears you have .006 etched on them.

speed_demon24

iTrader: (6)

The instructions that mine came with said .007-.009. Maybe they changed how they cut them? My old gears were motive too and the pinion depth on my new ones read .007 deeper than my old ones too. I think the old ones were the blue box motives though.

96lt4c4

iTrader: (5)

http://www.currieenterprises.com/ins...MotiveGear.pdf

I just Googled and found these instructions, that say .008 to .012. It does seem like the last set I installed said .007 -.009. Maybe the instructions I found are older. Either way I knew they didnt say .006. Maybe it was when they switched manufacturing. I have wondered if running them tighter like the AAM gears would help noise. But, I have been afraid to try it. The 3.90 Motives I just installed are very quiet but have a slight whine on decel. Not very noticeable at all.

I have also had some sets that have the pinoin depth on the pinion and no back lash on the ring gear. Should always go by pattern but its still nice to have as a starting point.