Huck's daily - 2005 Z71 crewcab

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TotalyHucked

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Then here's the drive side

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Pre-change/teardown on the left, new setup on the right

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TotalyHucked

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So I'm thinking either run it, or maybe put .001 back in the pinion or so.
 

TotalyHucked

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Decided not to make any more changes on the rear just yet. The carrier shims stayed the same, the pinion shim went from .029 down to .026 (OE was .036). Gonna call QP tomorrow morning first thing and get another set of bearings coming (probably order 2 so I have them for the front).

Any thoughts on what you see @legopnuematic ? I don’t think I wanna take any more shim out of the pinion, I think it will pull the pinion too far away. But the runout on the gear is certainly not ideal. That tells me that with the previous setup, I had a section of the ring gear that was too tight as far as backlash. That may have been the sound I heard. Now I have a small section that’s too loose. I feel like that’s better than too tight. If I add a smidge more shim back in, it’ll tighten up the backlash a tad but also sharpen up the contact patch down toward the root again.

Also got the front diff back down today. Had some glitter in the oil, slightly larger than normal glitter but no real chunks.

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Pulled the vent plug and decided to run a pattern. Painted 3 sections, roughly the same distance apart

Drive side

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Coast side
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TotalyHucked

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Drive side #2

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Coast side #2

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Drive side #3

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Coast side #3

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Not real sure what to think of these patterns, not sure if I should also be aiming for an oval or if that’s not how this one works. My book only covers 10/12 bolts. But it spins really nice.

It’s actually quite a bit looser than when I installed it. If you’ll recall, I made mention that after putting the whole assembly back together, it got really tight. Now it’s nice and easy to spin. Haven’t checked pinion drag yet but it’ll free spin a bit now.

Backlash also opened up a good bit. Before I was ~.017-.019 (.0085-.0095) but now I’m at ~.021-.022 (.0105-.011), so that’s a bit loose.
 

legopnuematic

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I say first do some checking to attempt to find out where the runout is coming from. 0.004 variation is fairly significant.

Set your indicator up to check the rear face of the ring gear, the OD of the ring gear, and on the back of the flange where the ring gear bolts are (if possible). If you have access to one, a test indicator or a dial indicator is my preference over a digital travel indicator.

The runout could be from the carrier not being machined perpendicular to the axis of rotation, or possibly not concentric. It seems pretty common for spools to not be perpendicular, certainly possible on an open/limited slip carrier though. The ring gear itself could be introducing it form the milling/hobbing process. Or there are burrs on the ring gear or carrier that is keeping things from sitting flat.

If you check as mentioned above that will provide some clues to where it is coming from. Depending on the cause there are different solutions. If the carrier is the issue, not much can be done outside of having it set up in a lathe and carefully trued up with a skim cut, which if done improperly makes bad go to worse. If the ring and the carrier both have runout, the ring gear can be indexed 180 degrees (or some other amount) and rechecked to see if the errors cancel themselves out. If burrs are present, then simply deburr and reassemble.
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