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I re geared my 10 bolt not too long ago with you guy's help, but somehow I managed to not see a chip on the pinion, it was towards the toe end, but none the less I rather not take chances. So I decided to get a new one instead, and it seems to be giving me more problems than my last one.
Here is my current fiasco
OEM shim .28
as you can see it looks too far for me
Depth 31.5 shim
I feel the 31 depth looks pretty decent I'm saying that because when I put a .33 or .35 the drive goes high on the heel and coast goes low and fat in the toe, a little like in the .33 picture but more.
Don't put on such a thick coating of marking compound. Apply very thin as to the point you can almost see thru it. When it's too thick,the wiping/meshing of the gears causes a re-coverup of the true pattern. I've seen seemingly bad patterns become good patterns just by reducing the amount of compound.
Also as you're rotating the 'compounded' ring gear,some of the compound with be applied/transferred on gear and as you rotate to/into an 'un-compounded' area of ring gear teeth,the compound on the pinion gear will transfer to the uncoated teeth of the ring gear and you will see an 'opposite' pattern of yellow on bare tooth instead of clear area on a yellowed tooth. I find that 'opposite' a true picture of pattern.
now that 31 pattern with less marking compound looks totally different than the 31 pattern with too much compound. The meshing areas are wider and not as pointed showing a truer pattern. The mesh area is central in the teeth.
Need 01ssreda4 to post in and give an opinion.
I have been toying with the backlash and got it tight at 7, I previously had it at 8-9 I thought it was 7 sorry about that. to this point I have been testing the pattern almost in the same spot, but today I noticed that my pattern looks different in different spots of the ring gear, I don't know what could be causing that but here is the difference, same .31 depth from previous but tighter backlash by about 1.5 though sands give or take.
To that point the drive side looks great in my opinion, but then here is another spot of the ring gear. same setting just different spot.
and yeah, the coast looks like *** on that particular area, note is just that area.
Its an 04 tahoe z71 suv, its a g80 gov lok, i replaced it with a rebuilt unit, my previous unit had a 2-3 backlash run out, i haven't checked this one, I'm just tempted it to call it and slap it in as is, what do you think?
Last edited by erickk120; May 4, 2017 at 10:21 PM.
Are these gears new? I would try a small backlash change to see if you can get the drive side more centered. I'm not saying it won't run, I'm just afraid you may get some whine from it.
Ive seen and had numerous Pinion and ring gears with chips, as long as they are not on the actual load bearing surface of the gear I've always just used a Dremel or a diamond hone to smooth the edges of the chip off, Its like drilling a hole at the end of the crack in sheet metal to stop the cracking.. Usual cause is because the gears got tapped against each other somewhere in manufacturing and chipped. Real common to get one when your horsing the carrier in to the housing and the ring smacks the end of the pinion...
This are indeed new gears, and my gears were at 6-7 backlash for the most part except for a 5 bl reading in one part of the ring gear probably carrier run out, I tried opening the back lash up a bit to 8-10, and re run the pattern, for some reason it came out shallow. The frustrating part with this gear set is that if I go deeper the pattern changes shape and becomes kind of slanted instead of oval. Thats whats been throwing me off all this time.
Now my question is does backlash affect the pinion depth or am I seeing gear ghosts?
This is the same pinion shim just loosened at around 8-9 backlash.
I Have no clue why but the coast is glued to the toe, only time the coast moves is lowering backlash. or pinion depth slightly.
So, I decided to increase depth by about .004 thousands and here I feel its too deep,
but as you guys can see it the drive changes shape. Here is where I need advice. in the pinion its in the middle and it looks like a slanted rectangle. pay attention at the ring gear negative drive pattern, where the other teeth get painted by the pinion.
I will drop .002 tomorrow see if I can find middle ground.
If I increase backlash not only the drive goes up but also changes shape, while if I keep backlash tight it stays somewhat towards the toe but its nice, long and oval. I will try lowering the depth by .002 and if it doesn't get me anywhere I think I might risk it by running the previous pattern. Yolo right??
Last edited by erickk120; May 17, 2017 at 11:24 PM.
Reason: extra info
What brand gears are these? I've done about a dozen sent of motive, and a half dozen Richmond and I can't recall ever seeing slanted patterns like this one is producing. You are doing right from what I can tell, just seems like something funky is going on with that gearset. Some gear pattern charts will say what you have is ok, which is why I say you can run it. I'm trying to help you avoid noise though, as I prematurely trashed a gearset which I'm actually replacing today, because the whine was unbearable in a daily driver type vehicle. No fun to go back and do this twice.
What brand gears are these? I've done about a dozen sent of motive, and a half dozen Richmond and I can't recall ever seeing slanted patterns like this one is producing. You are doing right from what I can tell, just seems like something funky is going on with that gearset. Some gear pattern charts will say what you have is ok, which is why I say you can run it. I'm trying to help you avoid noise though, as I prematurely trashed a gearset which I'm actually replacing today, because the whine was unbearable in a daily driver type vehicle. No fun to go back and do this twice.
Oh I totally understand, The gears are USA standard. Only reason I bought them over a set of Yukon's is because they had better reviews, but now that I know they are a yukon sub brand, I should have just gone with the yukons I planned. From what I've read this are technically yukon gears that didn't pass the tolerances for them to be sold as yukon gears, and or didn't get the final stage of refining reg yukons gears would get.
Here is an update: Warning massive power point of pics.
didn't get anywhere with the adjustment. I went back to the shim I had last time and tried lose backlash and tight backlash. Tight was 5 at its tightest and 8 at its loosest this is due to the run out. Then I tried loose from 7 at its tightest and 10 its loosest. I measure the ring gear in 4 spots, at 12 o clock 3 6 and 9 o clock. Here is the wedding album.
This is the 5-8 variance BL
Here it varies from 7-10 at its loosest.
sorry about the image spam, but I feel the tighter backlash gives a better looking pattern. All I know is that if I ever have to re gear I will never get USA standard.
Last edited by erickk120; May 18, 2017 at 03:33 PM.
Perfect example, I set up my motive 4.10s yesterday evening. Went with a 32 shim I think. First stab at backlash was 20, adjusted and it went to 3/4, adjusted and got it to 6/7, ran the pattern, it was perfect, centered and focused. That's why I don't get what the issue with these is.
Just an fyi... I just set up my 8.5 with a set of USA Standard Gear ring and pinion. In the book it says for a 7.5/7.6 Backlash for a "new" 2 cut gear should b 3-6. I would tighten it up a Lil and see how it looks.
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Re pattern check 
