Front 10 Bolt Gear Pattern Help

[89WhiteBlaze]

Hi all,

My brother and I are performing our first regear on a 10 bolt front axle. We thought we had the pattern pretty good, and so we pressed on our new pinion bearings in place of the set-up bearings and this is the pattern we got. Looking for some reassurance as to whether or not this pattern is acceptable. Any help is appreciated!

BL is currently 0.008"
This is the drive side which I think looks good.



This is the coast side. I think this also looks pretty good, but maybe favoring towards the root a little?

 

[Blue85]

That sharp edge at the root suggests that it's too deep. What is the measured backlash? You may be able to leave the pinion alone and back the ring up a bit.

 

[89WhiteBlaze]

Backlash is at 0.008"
Here is another pic of the coast side.

 

[obijuank5]

Definitely try and lose that sharp edge in the root. You're very close though.

 

[89WhiteBlaze]

Ok, I was afraid of that, but kind of thinking the same thing as well. Unfortunately he has already put the new crush sleeve and seal in...

So we need to take it back apart and remove maybe 0.002" from the pinion shim stack then right? Thinking this will probably push our backlash over 0.010", so I'm thinking that will probably have to be readjusted as well.

 

[89WhiteBlaze]

Or maybe as blue suggested, we could just pop the carrier out and move it away from the pinion 1 or 2 thou? Don't know if that would be enough or not.

 

[89WhiteBlaze]

Alright, so we tried adjusting the backlash, but didn’t seem to do much for the pattern. We took it back apart and removed 2 thou from the pinion and this is what we got. I think it looks a lot better. First pic is coast side, second is drive side. Backlash is still about 8 thou. Thoughts?

 

[Fastereddie]

You are referring to the drive and coast side backwards. If you had a high pinion front diff you would be correct like a rear axle. I would have left it alone with the first pattern. I think a lot of gears out now are showing that straight edge down by the root. Seems like they are finishing like that.

 

[Fastereddie]

Send it

 

[89WhiteBlaze]

I thought the more vertical/convex side was the drive side? And the slanted/concave side was the coast side? Or is the instruction book using terminology for a rear axle and it’s opposite for the front?

 

[Blue85]

It does look like this ring gear has 2 angles machined on the tooth, which would cause that straight edge. It wasn't clear in the first set of pictures. Hopefully there's some new information out there about this type of gearset. It doesn't make sense to let the pattern run over that edge, so I do like the new pattern better.

 

[Wes Harden]

Yes front diffs that are not high pinions, reverse rotation, are back wards.
Basically a rear upside down.

 

[Blue85]

So what kind of gearset is this? There should be some setup instructions from the manufacturer that cover this cut style.

 

[89WhiteBlaze]

It's a USA Standard gear set. Apparently it's a 5 cut gear tooth. They don't appear to give any kind of special instructions when it comes to 2 cut vs 5 cut other than the pattern on the 5 cut may be more of a "square" shape than a "slanted" shape.

 

[89WhiteBlaze]

So we are now finding about a 0.004" variation in our backlash measurements. We're getting about 0.006" to 0.010"... we've taken it apart 2 or 3 times and reassembled trying to clean it the best we can and make sure there are no burrs. It's tempting just to run it, but I guess our best bet is to find out if it's the carrier or the ring gear. We do have some other axles we could pull carriers from if we have to. Just sucks cause this is one of many things on our to do list before a wheeling trip next month and so far we're not making much progress.

 

[chulisohombre]

It looks decent. I’d run it. Front is not as important to have perfect. Remember it is cut so the rotation forward is reversed. It looks like mine was and it’s been good ten years now. If the carrier is Warped it could give different readings across the ring gear. But you’d be able to see that where it’s bolted on.

 

[Stephen]

USA standards are not a premium gearset but are generally good enough to perform OK. I regeared my burb years ago with an $80 gearset like that and it lived nicely. On a front low pinion, you'll drive on the coast side of the gear. This is why low pinions in front are a little weaker than a high pinion front. As said above, I'd focus on a decent pattern on the side that will be driven for your application and just make sure the coast side isn't terrible. For backlash change, make sure every thing is really clean under the gear and that the gear is really flat when it bolts on the carrier. We've also seen problems if bearing caps got mixed up. If you don't have the "super shims" for the carrier on that 10 bolt, you need some. It's basically a shim cartridge that holds the small shims in a sandwich so you can drive them in easily. It makes the carrier bearing shim work on a GM axle quite a bit easier than a Dana.

 

[89WhiteBlaze]

Yeah, there was a sale which brought the USA's down to essentially 1/2 the price of the Yukons and they seem to have good reviews... He was careful when putting the ring gear on and ran a file over the surfaces to debur anything. We're trying to eliminate any other possibilities before pulling the gear off the carrier as I'm guessing we'd need to get more ring gear bolts if we did since you're supposed to replace them. Might look into the super shims. Fortunately we were able to just flip the single, thick factory shims from one side to the other and that pretty much got our backlash on the money, excluding the variance of course.