[RifRaf]

Installing a new Detroit/Eaton Truetrac with US Gear 373 ring and pinion into my 12 bolt.
I started off with a .042 pinion shim, but the was too much (pinion was too deep into the ring gear)... so I switched to a .037 pinion shim with .009-.010 backlash and I think the pattern looks pretty good.

Turned the ring gear to get pattern. I did not put gear marking compound on all the teeth... some of the teeth shown are "Ghost Patterns". Both the Drive and the Coast patterns were "dead-on" consistent throughout the entire ring gear.

Drive .037 @ .009-.010 Backlash:

Coast .037 @ .009-.010 Backlash:

The ring and pinion gear mesh felt very smooth as I was turning the ring gear.
I just wanted to get some other opinions before I move to final set-up
Thanks in advance!

 

[modern malibu]

Looks perfect to me.I'd be happy with that pattern on any gear set.

 

[RifRaf]

modern malibu, thanks for the feedback!

Below are some photos of the final set-up with preload. I tightened up the backlash slightly with the majority of the readings in the .0085 - .0095 range (figuring that my backlash will probably open up .001). The contact pattern (both marked teeth and "ghost pattern") remained consistent throughout the entire ring gear.

I hope to have the rear end back in my car within a few days for proper gear break-in.

 

[BillyGman]

I've done a couple ring and pinion gear swaps myself, but what do you mean by "ghosted"? I've never heard that term used before.

 

[swampy 6x6]

hi
I would try another .003--.005 reduction in pinion height .Your pattern is close . Generally I like 60 % deep /toe no more . Current mark up is still a very small amount to deep .
The side to side or face / valley needs to be 50/50 it is already .

Always look at the main dark pattern not the fade outs .

Half the overhaul time for rear ends is in the setup time needed to get a good pattern .

 

[RifRaf]

I've done a couple ring and pinion gear swaps myself, but what do you mean by "ghosted"? I've never heard that term used before.

It’s just a term I picked up on the web.
In my situation, it means the gear pattern that was transferred from the pinion onto the ring gear teeth that did not have any marking compound applied to them.

See “Checking the Pattern - Alternative Method” in the link below.

StackPath

www.yukongear.com

 

[RifRaf]

I would try another .003--.005 reduction in pinion height .

The side to side or face / valley needs to be 50/50 it is already .

swampy 6x6, Thank you for the feedback.

It is my understanding that the face/valley (flank) gear pattern adjustments are done by changing the pinion shims... and you mentioned that I am already 50/50 (centered within the teeth).

My backlash is set on the tighter side... but still within the specified tolerance (.008”- .012). I expect the backlash of my new gear set to open up about .001” while driving... and that should put me right in the middle of the listed backlash spec.

I am pretty confident with my current set-up and I am very happy to report that during my first couple “gear break-in” drives, there is absolutely no noise anywhere in the differential during various driving conditions (acceleration,deceleration, light throttle, coast).

 

[swampy 6x6]

hi Yukon do great Pdf doco on how to set up gears ,better than most .

YukonKitInstallManual_Complete.pdf (yukongear.com)
page 18 ,summary, patterns go in opposite directions drive vs coast for 1x pinion adjustment

 

[David Bates]

swampy 6x6, Thank you for the feedback.

It is my understanding that the face/valley (flank) gear pattern adjustments are done by changing the pinion shims... and you mentioned that I am already 50/50 (centered within the teeth). And, you would be correct!

My backlash is set on the tighter side... but still within the specified tolerance (.008”- .012). I expect the backlash of my new gear set to open up about .001” while driving... and that should put me right in the middle of the listed backlash spec.

I am pretty confident with my current set-up and I am very happy to report that during my first couple “gear break-in” drives, there is absolutely no noise anywhere in the differential during various driving conditions (acceleration,deceleration, light throttle, coast).

Pattern looked fine to me.

 

[nitrofox]

hi Yukon do great Pdf doco on how to set up gears ,better than most .

YukonKitInstallManual_Complete.pdf (yukongear.com)
page 18 ,summary, patterns go in opposite directions drive vs coast for 1x pinion adjustment

that pdf is really informative