Ok. I've never set up a 14 bolt so that makes me understand better.
In that case, did you reinstall any existing shims, baffles, or slingers?
In that case, did you reinstall any existing shims, baffles, or slingers?
Ring and Pinion Gear Pattern Help
- Thread starter NashvilleTJ
- Start date
Depends on the differential. Deeper just means moving the pinion closer to the ring gear.
Yep 9 inch Ford, 14 bolt GM, most Eaton and Rockwell (Meritor) diffs use removable pinion carriers and the shim will move pinion away from the pinion.
So looking at all the pics again, your pattern in #9 looks best to me. That would drive me nuts not having any shims less than 10 thou.
OP
Thanks. I’m still not crazy happy with it.
It’s the kit from Yukon, and I thought it must be a mistake. But I checked and sure enough what I received is what comes with the kit.
I gave some thought to pulling the pinion bearing and placing a shim between gear and the inner bearing, but I don’t have a shim that size handy.
Anyone know of a 14 bolt shim kit with shims smaller than 10?
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OP
Here is the pinion carrier with the pinion gear installed. The gear rides on an inner and outer bearing, both of which are pressed onto the pinion gear shaft.
This thing is a press fit into the housing, and requires a large dead blow hammer to install it, and a large drift on the pinion gear straddle bearing shaft smacked hard with the BFH 5 or 6 times to remove it. As I understand It uses no gasket (except for the shims) or RTV to seal it.
It's a bit tricky to get the bolt holes lined up when installed - because once it's in it will not rotate. I found the best way for me was to lay it in place, thread some longer bolts in all six holes, and then pound it in with the dead blow. Then replace the bolts and torque it down. Took me three or four frustrating attempts to figure that one out.
Here is the case mount into which the carrier gently slides...
And finally, here are the shims. A 10, 11, 13, 16, and 2 19s came with the install kit. The one in the middle is the original 18.. Doesn't seem like they ever expect to need less that 10 for the setup. There are no slingers or anything else between the pinion gear and the inner bearing. At least I hope not...
There is a more detailed write up of the pinion setup over on my build thread.
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Try a G.M. Dealer for other size shims. I really would like to see a .005-.006 shim and .010-.012 backlash.
you can go to any GM dealers and order individual shims. GM doesn't offer shim kits for their bigger axles, you need to order individually.
- 0.15 mm (0.006 in)
- 0.18 mm (0.007 in)
- 0.20 mm (0.008 in)
- 0.23 mm (0.009 in)
GM spec for backlash with new gears is:
- The backlash between the ring gear and the drive pinion should be between 0.08–0.25 mm (0.003–0.010 in) with a preferred backlash of 0.13–0.18 mm (0.005–0.007 in).
OP
OP
Thanks William.
The ring gear was shaved because I shaved the 14 bolt housing with a kit from Ballistic fab. You can see the detail over in my build thread, but here is the cut:
And the result:
OP
Well, not wanting to leave well enough alone (I've got a problem that way...), I pulled the pinion gear apart and found a shim that would fit. It was thicker than I wanted at 49 thou, but it will work. It would certainly have been much easier just to get the thinner shims from GM next week, but I'm on a roll.
On the first shot I used a 56 thou shim stack on the pinion carrier to offset for the 49 thou added to the pinion gear - effectively making the pinion 3 thou deeper than my last setup. I did a pattern and it was going the right direction, so I pulled another 3 thou with a shim pack of 53. Backlash is 9.
And here is that pattern. I'm feeling better about it. It's nearly centered from the root to the face, and I don't think it's too deep.
What do you think?
On the first shot I used a 56 thou shim stack on the pinion carrier to offset for the 49 thou added to the pinion gear - effectively making the pinion 3 thou deeper than my last setup. I did a pattern and it was going the right direction, so I pulled another 3 thou with a shim pack of 53. Backlash is 9.
And here is that pattern. I'm feeling better about it. It's nearly centered from the root to the face, and I don't think it's too deep.
What do you think?
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now I get it. I had assumed you were talking about the mounting surface of the ring gear. My bad.
I would run that! Again, I would like a bit more backlash, but it’s not a deal breaker for me. Imagining the rest of the gear was there, the pattern looks nice. The only thing I worry about, is it looks like the pattern runs off the tooth, which will likely make a bit of noise. I will admit I have never set up a gearset that has been shaved.
That should get you going right there. Definitely no deeper you are on the verge of having a hard contact line near the root.
OP
In the documentation from Yukon, they show an acceptable pattern for the 14 bolt can run off both sides of the tooth. it says not to worry about that, but rather the key element is centering the pattern from the root to the face.
Does that sound correct?
Yes for any gear set you are wanting to be centered from root to crown and less worried about heel to toe. For comp use some will run on the deeper side but the gears will be noisy and run warmer.
OP
Hard to tell on these photos because the sight drops the resolution, but in person there seems to be a good bit of clearance to the root - about a 16th between the bottom of the pattern and where the root starts to curve away from the gear. And about a 16th from the face.
I was told by Richmond gears years ago that the shape of the pattern, and the placement of the pattern had little to do with the noise or longevity of the gearset. They just did not want the pattern to run off the tooth. Now, I don’t necessarily agree with the first part, but I do agree with the second part. I usually do a set up a few times to maximize the pattern. When you get the best pattern available, you are golden. Even if the pattern is less than perfect. Very few times have I been thrilled with a pattern. There is always a compromise somewhere. I still think your pattern is pretty good. If the pattern does not run off the gear, you are home!