Setting up gm 10 bolt HELP!!!

[Wiseco"3]

I've got a GM 8.5 10 bolt in my 84 short bed. I bought a Detroit tru tru trac diff. And a summit racing ring and pinion, I've got a tool to check pinion depth but it's a pain in the ARSE!! With that being said I've read on some other forums that guys who set rears up put factory shim back on and check gear pattern. If the gear pattern is good and pinion pre load is set as well as back lash it should be fine right ? Thanks in advance for the help

[GRADYS Performance]

If you want to do it right set the proper pinion depth on the new gear set. Proper pinion depth, proper pinion bearing preload and proper backlash is the only way to have good gear life with out any noise. I would suggest using an adjustable preload spacer with shims instead of a crush sleeve. You can PM me for info on the preload spacer. There are also adjustable carrier shims for setting carrier bearing preload and backlash.

[kalbert]

The factory pinion shim will get you in the ball park, definitely use it as your starting point. You may luck out and it will fall within the range that you can use. If not, you have a real good idea which way you need to go.

Setting up a rear end is a process for sure, but it sounds like you've got the right tools and know what needs to be done. Just don't take any shortcuts and you'll be fine. If it takes 10 tries to get the pattern right, so be it. You'll never forgive yourself if you cut corners and end up with a growler or worse. Once gears wear in with a howl, they howl forever and no amount of trying to redo the setup will fix them.

[Wiseco"3]

Thanks for the replys guys...well I got the rear end all set up, pattern looks good backlash was good. The only thing I didn't do by the book was pinion bearing preload because I couldn't find a torque wrench in inch lbs as low as I needed....ANYWHERE. So I guessed which I know you should never do. Well the reared has a slight howl under acceleration and decel. But when I'm cruising down the road at any speed and throw it in neutral it completely goes away ? Any ideas?

[GRADYS Performance]

You have to set the pinion depth by measurement not by pattern to make sure you do not have any noise.

[Wiseco"3]

I did use a pinion depth tool and got it as close as I could to the number etched on the face of the pinion. What is an acceptable tolerance because I couldn't get it exactly on the number

[GRADYS Performance]

I would suggest being within .001 of the pinion depth setting.

[Wiseco"3]

Ok thanks

[Wiseco"3]

One last question, I think lol when I put the new pinion in with no shims it was still 0.095 above the number on the pinion, but with no shims it couldn't be moved in the right direction. Meaning it needed to go 0.095 away from the ring gear but it already had no shims on it. How is this possible. I was using a ring depth tool with a dial caliper