First time rebuilding a 8.6

[Erickk120]

I'm running 0.034 worth of pinion shims, stock was .030

the most recent 3 photos are my last run are you referring to those?

8.6s seem to like it in the 30-36 area for the most part so you are in the right track, when I said shallow I meant the first set pics in your first post, then when I said they appear a tad deep, I meant that for your last set of pics. Which is why I asked if those are 2 cut or 5 cut, if two cut reduce backlash and re check pattern, if 5 cut leave alone and run with less compound and try to rotate the pinion smoother and with a load in the ring gear so it prints a true clear pattern. That last set is pretty close.

For reference this is what the current set in my truck looks like, Just a smidge deep as it will deflect and try to separate the gears when giving it the lead foot treatment, They looked great last time I serviced it, and installed a girdle for giggles, might upload a pic so that you can see it for the extra good boy points.

 

[Tatejohnson1122]

Yup just put everything together I ran one more test and thinned out the compound, here’s the results I’ll run a few heat runs through the and then check the pattern again.

 

[Erickk120]

Coast looks pretty good the drive looks messy, can you upload the negative side, as in the teeth you didn't coat but got printed by compound from the teeth you coated, Drive side, based on that line I suspect too deep.

 

[Tatejohnson1122]

So I ended up putting the truck all together last night, i noticed my preload was a little loose before assembling my rear end. I Tightened it up and re ran a pattern and the drive is more center (not by much but some), do you think that’s ok to start my wear in?

Sorry i just saw you reply I didn’t get any negatives of the pattern

 

[Erickk120]

If anything you are probably off by .002 in the drive side, but its your call, I would have tried a few more shims but there is that. Its never fun to be back there. Let us know how it turns, I know re setting preload sucks balls with the solid spacer.

 

[Tatejohnson1122]

I ended up giving it a go and everything is dead silent both drive and coast, I’m at 200 miles and slowly stepping up my top speed, i will keep y’all updated.

 

[2006Tahoe2WD]

I'm looking at doing this to see if I can tell where my whine is coming from. Did you clean the gears with brake cleaner? Is that necessary? Good job, I say the pattern doesn't looks pretty good. I'm no expert but I've watched maybe 5 Youtubes on this.