Looking for a little help on a project I have underway. I have an '81 CJ with '78 Scout II D44 axles and I'm in the process of installing a Eaton/Detriot TrueTrac carrier. I've never done gear setup before and I'm having trouble interpreting the contact patterns. Hoping someone can provide an opinion on what I need to do to get it right.
Some background - I am using the same ring and pinion as they were in great shape. I used new shims on the pinion of the same size as the old stack (old ones were damaged on the way out). I installed the pinion, set the preload, installed the carrier and shimmed to .005-.006" backlash. I applied the marking compound and turned the pinion applying drag on the ring gear. My challenge is that I don't really get ovals of contact as described in most guidance, but rather lines all the way across the gear tooth. The pattern seems a bit too far towards the flank, so maybe I need to remove pinion shims, but it seems odd that I'd have to change that with the same gear set.
I attached a couple pictures of what I've got now. I appreciate any knowledge you can provide.
Thanks for the references. I appreciate it. I have found these on the internet and reviewed, but I'm just having a hard time interpreting my results. Probably just need to make some adjustments until I start to see it more clearly. I found a couple of other strands suggesting that a thick line across the flank suggests that the pinion is too close. I'll try that tonight.
So... its been a while since I posted, but I've tired a lot of combinations since then. If anyone is looking to do this project, I suggest buying your supplies from Yukon gear and axle. I purchased two shim kits that had nearly no variety between the 5 pinion shims that were provided. Just received my Yukon shim stack tonight and was very pleased with the quantity, variety and quality.
After trying lots of different combinations of pinion and carrier shims, I've found that I cannot get the drive side pattern and the coast side pattern to converge on the center of the ring gear tooth (between the heel and toe) without causing the pinion to be too deep. Since most articles, including the one that John shared suggest that centering the pattern between heel and toe is not critical and often unattainable, I decided to stop chasing that aspect of the pattern. I worked back toward the size of the original shim pack and reached a point where the pattern appears fairly centered from face to flank (see pictures).
Hoping to get some opinions on whether this pattern has any obvious flaws. Looks to me like maybe .005 less on the pinion shim to be fully centered from face to flank. Any common (or uncommon) mistakes that prevent getting a pattern centered between the heel and toe? If this was your rig, would you give this pattern a shot or keep working it?
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