Broke my Motive 3.73 gears in my 10 bolt rear-end last fall. I have a buddy who had a used set of Motive 4.10 gears he gave to me. This is my first gear install so I used the original pinion shim to get me in the ballpark and have backlash set @.009 and this is the pattern I am getting...







What is causing the odd pattern on the coast side? How does the drive side look for used gears? Are the gears junk or do I need to start from scratch? Thanks for any advice!

Jeff

 

your shiming is way off, the contact area should be a fairly even footprint, not wearing the compund completley off in one area, the marks should also be fairly deep into the teeth should. Think about it, when you put power to the gear you want the most contact area for that power to transfer to. Also improperly shimmed gearsets will whine and wear incorrectly. Keep shimming and re-shimming till the gears mesh correctly, usually take 5 or 6 shots, patience is key.

here is a link that may help:

http://www.drivetrain.com/parts_cata...tructions.html

 

from the way that pattern looks you need to shim the pinion out

 

Agree.

 

Thanks for the advice guys, I needed it! I will keep track of what shims I use and post up more pictures of the results I receive. Hopefully I can make this thread into a good "cause and effect" to help other members too! Will keep everyone updated in the next week when I change out some shims.

Jeff

 

I measured my stock pinion shim at .030". I installed a new shim of .017" (thinnest pinion shim in motive gear install kit). Backlash is a little on the tight side at around .006". My pattern still looks like crap!!! Any other ideas or should I junk these used gears and start over with a new set? Thanks again for any advice!

Jeff

 

When setting up a used ring and pinion, you want to pay more attention to the coast side pattern. unless they are very low mileage gears. I think you could increase backlash a hair , but personally I would run it like that.

 

they look like there still shimmed the same, the contact area has only moved a little, its still wrong, they need to look like the pictures on the website i posted. Try it again, you need to get it right now, once they are setup wrong and ran the gear will be wrecked.

 

I also tried running a .050" shim on the pinion gear and the pattern still barely changed... I don't get it? I tried no pinion shim at all and the pattern still looked horrible - barely made contact on ring gear for drive side. Any suggestions on what move to do next... pinion in or pinion out, etc.? So far this project has not gone as planned!

Jeff

 

working on cars usually dont, the unexpected always happens, the pinion needs to be shimmed out as stated earlier... keep trying till its right

 

Black 97 SS,

I have completely removed the pinion shim and the bearing is seated fully at the bottom of the pinion gear. With no pinion shim at all that is as far "moving out" as I can move the pinion gear and I still have the same weird looking "V" pattern on the coast side with barely any change in pattern in relationship to heal/toe.

With these gears being "used" I am just wasting my time on a set of possible junk gears??? The odd coast pattern is what really concerns me. Thanks for any guidance!

Jeff

 

Pinion shim is usually dictated more by the case, and less by the gearsets so start off with the stock pinion shim and work from there. Get a decent pattern on the coast side like the other guy said and it should be quiet.

 

yea really the coast side is what matters rhe most like kevin and other already have stated.obviously because thats the side that will make contact while driving forward.