I rebuild my 9.25 rear end about 2 months ago after my posi clips broke loose. I replaced the carrier with Auburn and put all new bearings in. I used my old ring and pinion.
Set carriers at 75 lbs. Pinion at at around 200lbs untill the preload was at 12inch pounds..
Back lash at .06. Used the same pinion shim it had stock.
But my problem is it makes a humming noise at all speeds. Works fine no vibration and feels good.. I have had it like this for about 3000 miles. I removed the cover this weekend and checked back lash which was still at .06 and ran a pattern check.
This is what I got…

2004 quadcab 1500
Hemi 120,000 miles

..

 

Hard to see the pattern with that blue...(I know...I used it too). Looks like the contact is deep into the root of the gear tooth?? If so, you need to take them out of mesh some....reduce the pinion shim. ??? But doesnt make alot of sense if you reused same. Are you sure you got the pinion bearing races fully seated in the housing?

 

Yes I am sure the races are in good, I even sanded the seat were race goes into incase I smashed the edges which wouldn’t allow the race to seat good.. I’m sure they are in good..
I think your right, they do look a bit deep. Just wanted a second opinion..
Its so hard to tell because the teeth make almost complete contact.

 

I agree with truedogman drive side looks deep.

Did you set the BL to 0.06" or 0.006"?

 

I meant .006 on back lash

 

Check all specs..If I remember pinion shaft 25 inch pounds of drag on preload.
back lash seems tight .012 backlash seems to be the number .Remember smaller the backlash when that rear end heats everything expands.To large of backlash you get that slam in the diff .Make sure all bearing races are seated and timken is the only bearings I use..Go to your local rear end shop and mark your shims left and right give them your current specs and then give them the specs your trying to achieve and they will hook you up with new shims.

 

Preload is pinion shaft only nothing else..Just wanted to clarify that drag spec.

 

I tried backlash from .004 to ..018 and the noise seemed uninfected. . The carrier bearings dont use shims they are adjustable.
The friking pinion preload was hard cuz it took a metal pipe on the end of my breaker bar to crush the crush sleeve. I was sure something was gunna break but nothing did expect for my Craftsman ¼ breaker bar I broke 3 of them trying to crush the crush sleeve..

 

I know it sucks that you have to pull the pinion out and use less shims to move the drive side gear pattern more towards the top, but, hey, we've all been there, grab a 6 pack and take your time. You might want to go w/ a solid spacer.