Hello All,

I do not post much but I am a regular reader. I am grateful for all of the information on the site.

I have a 8.5 10 bolt that I put a 30 spline truck truetrac and 12 bolt moser axles. I changed the gears from stock to 4.10 and installed all the above with a great wear pattern. I reused the shim under the large pinion bearing. I never ran the gears because I read this site and am now building an 80mm billet turbo lq4 4l80e combo.

I changed the gears to a more turbo friendly 3.42, and now the wear pattern looks off. It looks to my novice eye that the pinion is too high and needs a bigger shim. In all my lurking here and elsewhere the norm is the stock shim is reused and is usually fine. Can you please look at the pattern and tell me if I should add a shim? If so, how much would be a good guess?



Thank you,
Bill

 

Here's an old thread from about 2 years ago concerning pattern and marking compound.

https://ls1tech.com/forums/gears-axl...ern-check.html

Read posts 3, 4, and 5 of that thread, concerning the application of the marking compound and how it'll show true pattern on un-compounded teeth.

 

Thanks for the response. I finally got around to adjusting the gears. I took the pinion off and the shim was .020. I found the old one from the original gears and it was .030. I added the .030 shim and this is what it looks like.

I didn't have a .025 shim.

I'll take a pic of the ghost pattern in a bit.

 

Ok, so I am waiting on the marking compound. I tried Prussian blue and Desitin with coloring. I don't like the way it looks. The marking compound should be here tomorrow. I'll post an update then.

Thank you,
Bill

 

Is the 'ghost' pattern what I refer to as carryover of the compound to the unmarked gears ? If so, those look good. Compound still looks too thickly applied as compound looks smeared and dragged to cover true pattern. Apply it so thin that you think that ain't gonna work and see what the pattern is. A little tube of marking compound lasts me a very long time.

 

Thanks for the reply. I will apply it thin tomorrow when the compound comes in. That is Desitin and dye.
Bill

 

Here is the new pattern with lightly coated teeth.

 

Coast side ( pics 1-4 ) and drive side (pics 5-7 ) all have a nice wide/long centered pattern.

 

Thanks for the reply. I am going to run this pattern. I'll report back when I get.the car running.

Thanks again Bill

 

Most of the rear ends that I'm involved in with the set-up are setting up 'used' gear sets. When I establish a pattern I like, it's for the purpose of longevity, not quiet/noisy. I would rather have long lasting non-quiet rear than a quiet soon to wear out rear. I'm not saying you can't have both.

You never mentioned what brand gear set it is.

 

FirstYrLS1Z thanks again for the reply,

The gears are new and Richmond Gear EXCel Ring and Pinion Sets GM85342.

Thanks,
Bill