Gear pattern check

[Jzeus]

I’ve read through a lot of threads here and got a lot of information, just wanted to have my pattern checked.
Chryco 8.25. Revolution 4.10s and Eaton truetrac

This is the best pattern I’ve come up with, if I go .001 deeper the drive side is too deep, .001 thinner the coast side is too shallow.

 

[Jzeus]

This is .001 deeper than the pics in the original post

 

[Jzeus]

Anyone?
I picked up a good set of micrometers, apparently the calipers I was reading wasn’t consistent. I’ve got a shim stack made exactly .001 thinner than the pics in the first post. Gonna try them tonight and see what happens.

 

[Bigfoot-NM]

@hosejockey61

 

[Jzeus]

Right at .001 thinner than the pics in the first post. I tried the .030 what revolution recommends but it was way shallow.

 

[hosejockey61]

That's too shallow. Add 3-5 thou and rerun. Use far less marking compound. Just enough to turn them yellow. What's your backlash at? What's the spec for the 8.25?

 

[Jzeus]

That's too shallow. Add 3-5 thou and rerun. Use far less marking compound. Just enough to turn them yellow. What's your backlash at? What's the spec for the 8.25?

I was looking at the line at the bottom of the drive teeth thought it was too deep. But will run another one tomorrow. Not sure on the 8.25 backlash. Been running at .006 what revo calls for.

 

[hosejockey61]

I was looking at the line at the bottom of the drive teeth thought it was too deep. But will run another one tomorrow. Not sure on the 8.25 backlash. Been running at .006 what revo calls for.

Ok as long as BL is in spec is all I care. The harsh line at the bottom is mostly buildup of excess compound. That's why I tell people to just turn them yellow, but not more than that.

 

[Jzeus]

.003 deeper.

 

[Jzeus]

I can’t really tell. But that one looks just a hair, maybe .001 deep?

 

[hosejockey61]

The drive side looks good, the coast side looks shallow. Since this is a low pinion rear axle, we want to focus on the drive side. I think you may be as good as it gets. When this happens to me, I always find what is definitely too deep and definitely too shallow in order to bracket it. I think you're there though.

 

[Jzeus]

What’s the percentage of this making noise? lol. I’m fine with a minute amount. I’ve got some pretty aggressive tires which will drone you to sleep. Just as long as it doesn’t grenade into a molten ball of metal and leave me stranded. I’ve never done anything like this. Most I’ve done was rebuild my xfer case and install a sye. But there was no setup with that. And I ended up getting a bad chain, sounded like a twin screw supercharger so I ended up putting the old one back in.

 

[hosejockey61]

I couldn't give you a percentage. I think it's fine though. If you're worried, then bracket it to be sure.

 

[Jzeus]

Ok I may run a few more just to see, never hurts to learn stuff, but Just out of curiosity tho, if you ever run into one that a thousandth makes it too deep or too shallow do you run it to the deep or shallow end? I would think deep, so the gear would have more “bite” but I’m totally new to this and still learning.

 

[Jzeus]

I think the 365 is gonna be it also. I got bored tonight and ran a couple more. One at 355 and one at 372. The 355 one put the coast up too high in a smiley face. The 372 I ended up getting a too straight of a line on the drive. And a little hardness on the coast. If it eats them I’ll just get a set of spicer gears coming. Or find one in a junkyard that’s already got 410s in it. But I can guarantee one thing. I’ll never do this again. I’ll rebuild 100 transfer cases before I’ll set gears up again, at least with it still in the vehicle

 

[Jzeus]

Ok, one last question. I’m gonna try to button this thing up tomorrow, the way it was it has a flat washer and a lock nut, the kit came with a flare lock nut, the kind that has the washer made to it. I won’t reuse the flat washer with that style nut correct?

 

[Rickyd]

Ok, one last question. I’m gonna try to button this thing up tomorrow, the way it was it has a flat washer and a lock nut, the kit came with a flare lock nut, the kind that has the washer made to it. I won’t reuse the flat washer with that style nut correct?

The 8.25 has carrier bearing adjusters() but I don't remember if it has a crush sleeve. If so you probably want to start to crush it with the old nut/washer without hitting preload before switching to the flange nut.

 

[hosejockey61]

Ok, one last question. I’m gonna try to button this thing up tomorrow, the way it was it has a flat washer and a lock nut, the kit came with a flare lock nut, the kind that has the washer made to it. I won’t reuse the flat washer with that style nut correct?

Correct. If the new nut is a flange nut, then no washer needed.

The 8.25 has carrier bearing adjusters() but I don't remember if it has a crush sleeve. If so you probably want to start to crush it with the old nut/washer without hitting preload before switching to the flange nut.

I agree with this.

 

[Jzeus]

So I hit a problem. The space for the truetrac won’t slide in, it’s close. If I bumped it with a hammer it would go but I figure it needs a tiny bit of play, should I take a little off the spacer or the ends of the axles? I’m talking about maybe .010-.030.

 

[machoheadgames]

So I hit a problem. The space for the truetrac won’t slide in, it’s close. If I bumped it with a hammer it would go but I figure it needs a tiny bit of play, should I take a little off the spacer or the ends of the axles? I’m talking about maybe .010-.030.

You’re saying that with the c-clips inserted and axle shafts pulled all the way out, the provided axle button spacer that drops in between the shafts won’t fit?

Are you sure the axle shafts are pulled all the way out? I have seen people post before that their c clips wouldn’t sit properly in the groove of a truetrac (on a Dana 35, not C8.25, but still) and so they wouldn’t be able to I’ll the axles all the way out by a bit.

And yes, you want a very small bit of play. It’s kind of funny you’re having this issue because the Dana 35 truetrac has the exact opposite issue. The spacer provided is too small and the axle shafts are able to slide back in forth by about 0.080. It makes a loud clunk constantly and people say that it actually makes you have to countersteer on the road because the rear end walks. I had a Dana 35 TT with the same issue but I had a custom spacer made by a guy near me to fix it, so I never saw how it drove on the provided spacer. I did verify that the axles moved too much for my comfort.

Regardless, hope you can figure something out. I’d probably machine down the spacer.