I'm in the process of installing new Motive 4.30 R&P in my '01 Sierra 1500 with the 8.6 rear end. I used the same thickness pinion shim as was on the factory pinion. I bought a pinion depth checking tool from Ratech, but's kind of difficult to get a good reading.

I installed the new Detroit TrueTrac using the factory shims. Amazingly, I've got good bearing preload with a backlash of .007". Here's the resulting pattern. I marked three teeth in two different locations. Take a look and let me know how it looks to those of you that have some experience with this. This is the second truck I've setup. But the other one was quite a few years ago. I've got the ability, but not the experience. Once again, please take a look and let me know ASAP. I'm waiting on your response to button this thing up Thanks.

1st drive pattern


1st coast pattern


2nd drive pattern


2nd coast pattern