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Discussion Starter · #1 ·
These last two gear swaps have been the one of the most frustrating things I have done in a very long time. And all from trying the crush the collar.

Here's the latest problem, buggered up pinion threads.
It's a new pinion and I was using the old OEM nut that I've had on and off it several times during the initial gear set up. Plan was to use the old nut till the collar began to crush and then switch to a new one.
Never hit the threads, or did anything with the nut.

Is it possible that the torque multiplier is causing this. Don't know how, but I can't think of anything that I did.
I have a crush sleeve eliminator and will be switch to that once I get the threads cleaned out.

I went to do the final install with the crush sleeve, using a torque multiplier and everything got jammed up after some tightening.

Luckily, it looks like just the top 2 or 3 threads are damaged.
What's my best bet here?

Thanks again.
 

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High Performance Rear Ends
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Wow, that looks bad. Most of the time the nut will get damaged and the pinion will be fine. The pinion is hard enough that it usually doesn't get damaged. I've had to grind the first few threads off before. It's very hard to fix the threads on the pinion because it's hard.
 

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Discussion Starter · #4 ·
I went with Yukon because I thought they were one of the best around. I think I was wrong.
The front axle pinion nut was also showing signs of damage during my many attempts to crush the collar.

Should I take it to a machine shop and see if they can clean it ?
I can't find info on the pitch and thread count, or I'd just get a dye and try that also.
I can still run the nut all the way down, so the starting, top thread is still there enough to start the nut.
 

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High Performance Rear Ends
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I'm a toolmaker, and I don't know of a good way to repair that. I've put them in my lathe and tried using a thread file and other methods and it usually doesn't work. If you found a die that size it would likely just damage the die.
 

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Discussion Starter · #6 ·
I'm a toolmaker, and I don't know of a good way to repair that. I've put them in my lathe and tried using a thread file and other methods and it usually doesn't work. If you found a die that size it would likely just damage the die.
Then as Chasracer said, I'll try a file and if that doesn't work, it's grinder time.
But if the file does work, that's not a good sign for the quality of the gear.

Thanks again.
 

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Race it, Don't rice it!
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Looks like the locking part of the nut tore it up. I don't think there is a way to get that cleaned up or repaired without costing more than replacing it with a different set.
I'd grind it off and live with it. Lock tight will work in it's place.
 

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Dremel hast an ultra thin cutoff wheel available. I would use one of those. Start with clearing the boogers that are rolled up in the root of the thread. Go slow, once you get them out, I would go to a thread file to polish up the faces of the thread. There is nothing you can do about the removed material.
Grind off the locking part of an old nut, so that it will spin freely for test fitting. You can use a press to "pre-crush the crush sleeve to get close, that way you won't have to use the nut as severely.
If you have some moly cam pre-lube, use that to coat the threads during mock-up and fitting.
 

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Discussion Starter · #9 · (Edited)
Looks like the locking part of the nut tore it up. I don't think there is a way to get that cleaned up or repaired without costing more than replacing it with a different set.
I'd grind it off and live with it. Lock tight will work in it's place.
Thing is I was already using an old nut that has been on and off many times. It's rounded enough so the crush of the nut isn't really there anymore. And I just used the same nut to run it on and off by hand.
I really think the heat treatment process on both these gears is bad, but there's nothing I can do about it now.

Dremel hast an ultra thin cutoff wheel available. I would use one of those. Start with clearing the boogers that are rolled up in the root of the thread. Go slow, once you get them out, I would go to a thread file to polish up the faces of the thread. There is nothing you can do about the removed material.
Grind off the locking part of an old nut, so that it will spin freely for test fitting. You can use a press to "pre-crush the crush sleeve to get close, that way you won't have to use the nut as severely.
If you have some moly cam pre-lube, use that to coat the threads during mock-up and fitting.
I went through many attempts to pre-crush the collar on the front axle and could not get it right. I have a harbor freight press and everything on it was flexing during the crush, so I couldn't really tell what was going on just with the collar.

I was just able to clean the threads with a file so I can run the old nut on, off easy. I have a new nut coming in the mail and will use that for the final install.

I already have a crush sleeve eliminator for the axle (bough it when I was having the same issues with the front).
I just de-burred it and I'm soaking the shims in gas right now. I'll work on that tomorrow.

The fact that I can use a file on the threads and clearly see the removed material tells me something isn't right. I don't think Yukon is going to give a crap about any of this if I call and tell them what's going on.

Edit:
This Jeep hates me!
Just went and tried out the crush sleeve eliminator. After narrowing it down to using only the large sleeve and non of the shims, the preload is at about 12. Specs are 22 to 35.
Guess I'll be doing some sanding on the sleeve tomorrow.
Using moly on the threads is the way to go.
 

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High Performance Rear Ends
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Just be sure that you get all of that molly off of it before the final assembly. Use red Loktite on it. When you sand the spacer be sure to measure it in several places to be sure that you are removing material evenly all the way around.
 

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Discussion Starter · #11 ·
Just be sure that you get all of that molly off of it before the final assembly. Use red Loktite on it. When you sand the spacer be sure to measure it in several places to be sure that you are removing material evenly all the way around.
I think I got it. I put a socket in a vice, one that just fits the ID of the spacer. I had the spacer stick up just a hair, while the bottom of the spacer rested on the vice and was able to file it pretty evenly this way.

I measured all around many times and got to within .002'ish of being even. Is that OK, or do I need to do better?

I torqued it down and got 28 in/lb of preload, spec is 22-35.
I've already sprayed down the threads, but will do it again before installing the new nut with loctite.

Thanks again for everyone's help!
 

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I try to kep them within .0005 all the way around. If it's higher in spots then it's going to load the bearing unevenly. If you have shims that are around .001 or .002 thick then I woudl work on it some more and try to get it more even all the way around and then use shims to make up the thickness to get the preload right.
 

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Discussion Starter · #14 ·
Tried to clean it up , but could not get it without getting too much preload. Had to start over on the spacer, filed it down a bunch first then got it to .0005 true on sandpaper and used the thinnest shim to get the preload to 29, still within spec, but on the tight end. I'll need to wait till next week to get the new nut before I can wrap it up. All the setup is done, just need to do final checks and assemble.

I had a thought on maybe why the threads got messed up. I think when I was installing the yoke, I hammered it down (using a dead blow) so only a couple of threads were showing and then I used the impact to draw the pinion through the outer bearing and the yoke. I think this may have been too much force for the first couple threads and they let go.

I think this will be my last time messing with crush collars, unless no choice.

Thank you all again.
 

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Well " Infinite Monkeys " sure hope you ain't going to shot the messenger for suggesting using a multiplier LOL. Think you are right about the yoke theory. They say life is a learning curve, hope that this is not a expensive learn for you and all goes well.
 

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Discussion Starter · #16 · (Edited)
Well " Infinite Monkeys " sure hope you ain't going to shot the messenger for suggesting using a multiplier LOL. Think you are right about the yoke theory. They say life is a learning curve, hope that this is not a expensive learn for you and all goes well.
No, I don't think it's the multiplier now. It's just the first thing that came to mind because I couldn't see what I had done wrong. The multiplier allowed me to crush the front sleeve and I'm still gonna use it to do the final tighten on this nut as well.

Also, I think I had so many problems with the front nut because of the same reason as this.
I remember removing the front nut after snapping a breaker bar when tightening and realizing the nut was seized in place and not even touching the yoke. Damage while drawing the yoke with just a thread or two makes most sense to me, now more than ever.

Now I used a floor jack and a piece of wood to hold the pinion up while I hammer the yoke down till I had 4 or 5 threads showing. I'll make this my standard practice.

I am still concerned about the final torque with the new nut because of the crush and the narrowed area when it will contact the damaged thread section, hope it wont bind.

What do you all think about just removing the damaged threads, just to prevent bind? They no longer serve a purpose and may only cause a problem.
I did buy 2 new nuts, so I could just try it and see what happens with the first one.


Thanks again.
 

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Unless you can find a split die that you clamp on further down the thread and wind back off the thread you will have to just remove the damaged thread. Do not think using an ordinary die from the end will be very successful and may do more damage. Next problem is will the new nut still retain on the shaft okay.
 

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Discussion Starter · #18 ·
Unless you can find a split die that you clamp on further down the thread and wind back off the thread you will have to just remove the damaged thread. Do not think using an ordinary die from the end will be very successful and may do more damage. Next problem is will the new nut still retain on the shaft okay.
I'd say there are 1 and a half to two threads on top of the old nut showing now that it tightened down all the way. Which means the nut is using all but one of the very top threads. That should be good enough, I think, plus loctite.
 
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