9" gear pattern

[lt1nova]

I'm in the middle of my first gear swap and would like opinions on this marking compound pattern for someone who's done it before. It's a used set of 4.11's, currently at .012" of backlash. Currently have a .017" Shim installed.
coast1.jpg
coast2.jpg
drive1.jpg

[BIG CAT]

Pinion is to deep. The drive side(pic3) needs to be marking in center.

[z28cam70]

x2 on the pinion being too close. try a .015" shim on the pinion and if those are new bearings i would tighten up the backlash to .008"-.009". although .012" is within spec(.008"-.012") when the new bearings break in your backlash will increase and go out of spec.

[lt1nova]

I will pull the pinion out a bit and re check. The carrier bearings are used, only the pinions were replaced. I was shooting for .010 for backlash.

Thanks guys!

[lt1nova]

I've finally getting back to the gear swap. I pulled out some shim, I got .006" in there now and .006" of backlash as well. Randy's Ring & Pinion said on another message board to shoot for 6-8 BL.

a.jpg
b.jpg
c.jpg

[BIG CAT]

i think you went the wrong way with it. put a .020 or .022 in it and recheck it.

[lt1nova]

I'll give it a shot tonight. Thanks Big Cat.

[z28cam70]

if you put a bigger pinion shim in there it will push the pinion gear closer to the carrier. try increasing the backlash that will help bring the pinion back some. also make sure the inner pinion bearing is seated on the race. what do you have the pinion preload set to? should be at 20-25 in.lbs.
do you still have the original pinion shim and gear and what markings were on the old and new pinion gears? did either have any + or - numbers marked on them?

[lt1nova]

Z28cam70 Are you thinking this is like a GM rear? Adding shim thickness to a 9" pulls the pinion away from the carrier.

[lt1nova]

There were no numbers on the either gear set that I noticed indicating pinion depth. The pinion preload is 25 in lbs.

I reset up with a .012 shim and .008 backlash. More shim pulls the pinion away from the carrier on a 9".

012-008a.jpg
012-008d.jpg
012-008e.jpg