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Old 07-03-2012, 01:45 AM   #1
basshawk
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Used rear end gear mesh help.

I replaced my yoke on my 12 bolt truck rear end. I decided to change the crush sleeve to a solid spacer at this time. I did not check the wear pattern on the gears before I took it apart. I did not change any shims and thought that the rear end would function the same if I put everything back where it came from. Now I have it back together and it seems as if the pattern is towards the toe of the gear with it completely coming off the gear on the coast side. This is the first rear end I have taken apart and was wondering if someone with more experience would look at the pictures and give me their opinion. Any help would be greatly appreciated.
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Old 07-03-2012, 07:10 AM   #2
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Re: Used rear end gear mesh help.

Subscribed. Looking to fix my leaky pinion, going with the solid spacer, will be good to learn what to do first.
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Old 07-03-2012, 11:10 AM   #3
chebyshortbox65
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Re: Used rear end gear mesh help.

Put the old crush sleeve back in Anne tighten the pinion nut till you can barley feel a slight drag the solid crush sleeve did not change Tue wear pattern the crush sleeve only sets the preload on the pinion bearings
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Old 07-03-2012, 11:32 AM   #4
basshawk
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Re: Used rear end gear mesh help.

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Originally Posted by chebyshortbox65 View Post
Put the old crush sleeve back in Anne tighten the pinion nut till you can barley feel a slight drag the solid crush sleeve did not change Tue wear pattern the crush sleeve only sets the preload on the pinion bearings
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Why would i put the old crush sleeve back in? It is set up with solid spacers to spec.
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Old 07-03-2012, 11:58 AM   #5
chebyshortbox65
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Re: Used rear end gear mesh help.

Never liked using them with an old set of bearings I only like using them on a fresh rebuild just my
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Old 07-03-2012, 11:26 PM   #6
Dsquared
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Re: Used rear end gear mesh help.

if you have a dial indicator,set it up and shim ring gear to 8-10 thousands back lash. check your mesh again,you generally want it just out of the valley of the ring gear. too far out and it will whine and take out the pinion. too deep and it will take out both.
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Old 07-03-2012, 11:29 PM   #7
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Re: Used rear end gear mesh help.

looks like you need to set the pinion a little further....may have to trim the spacer
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Old 07-04-2012, 12:38 AM   #8
kelsfine69
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Re: Used rear end gear mesh help.

If all the same shims were used then the pattern should not change that much. Changing a crush sleeve and resetting rotating torque should give you the same pattern. I put a set of used gears in with the old shims and new bearings and checked the pattern. It should whine but its quiet?.
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Old 07-04-2012, 01:01 AM   #9
basshawk
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Re: Used rear end gear mesh help.

Quote:
Originally Posted by Dsquared View Post
if you have a dial indicator,set it up and shim ring gear to 8-10 thousands back lash. check your mesh again,you generally want it just out of the valley of the ring gear. too far out and it will whine and take out the pinion. too deep and it will take out both.
I checked the backlash and i am running 9-10 thousanths. Considering these are used gears, does this patters seem acceptable. Thinking bout just trying it and seeing how it sounds? Just dont know if it is possible if something changes if you simple take it apart and put it back together? All of your feedback is greatly appreciated. So if i am understanding correctly i just want to make sure the pattern is between the root and land and not worry too much about the heel/toe?
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Old 07-04-2012, 01:03 AM   #10
basshawk
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Re: Used rear end gear mesh help.

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Originally Posted by kelsfine69 View Post
If all the same shims were used then the pattern should not change that much. Changing a crush sleeve and resetting rotating torque should give you the same pattern. I put a set of used gears in with the old shims and new bearings and checked the pattern. It should whine but its quiet?.
Yeah i agree with this, my pattern just seems like it is really close to the toe side.
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Old 07-04-2012, 01:06 AM   #11
basshawk
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Re: Used rear end gear mesh help.

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Originally Posted by chebyshortbox65 View Post
Never liked using them with an old set of bearings I only like using them on a fresh rebuild just my
.02
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From your experience, whe not on used bearings? The adjustment seems incredibly touchy. Add two thou and too loose, take away 2 thou and seems too tight (pinion rotational force). Is this why you only do it on new gears?
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Old 07-04-2012, 01:09 AM   #12
basshawk
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Re: Used rear end gear mesh help.

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Subscribed. Looking to fix my leaky pinion, going with the solid spacer, will be good to learn what to do first.
Seems like you are attempting the same huh? I want the solid spacer so i never have to deal with a crush sleeve again.
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Old 07-08-2012, 12:06 PM   #13
raceman6135
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Re: Used rear end gear mesh help.

Call me crazy, but spending $5 for a new crush sleeve every once in a while (how often do you plan on tearing into the differential?) saves me so much time over fiddling with a solid spacer that I use crush sleeves in everything except a very high horsepower application.

As for your particular wear pattern, yes, it's going to need an adjustment of one- to two-thousandths to be near perfect. The trouble may be, though, that if you try to adjust it now that the gears have already established their wear pattern with each other, you may experience high and/or accelerated gear wear.
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Old 07-09-2012, 11:58 PM   #14
basshawk
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Re: Used rear end gear mesh help.

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Originally Posted by raceman6135 View Post
Call me crazy, but spending $5 for a new crush sleeve every once in a while (how often do you plan on tearing into the differential?) saves me so much time over fiddling with a solid spacer that I use crush sleeves in everything except a very high horsepower application.

As for your particular wear pattern, yes, it's going to need an adjustment of one- to two-thousandths to be near perfect. The trouble may be, though, that if you try to adjust it now that the gears have already established their wear pattern with each other, you may experience high and/or accelerated gear wear.
I was thinking the same thing, however everybody seems to hype up the "crush sleeves are hard" scenario. My thinking was If I blow up my yoke, I don't have to fiddle with a crush sleeve again. Yes I am also aware that my U joint is more likely to blow up than my yoke. Really I just don't want to open my pumpkin again and worry about my gear mesh if by some chance it doesnt make noise.

As far as the accelerated wear, I agree 100 percent as this was probably where they were originally set up, being wrong or not and you don't want to break it in in two different positions. I will post the results of what fails when I fire this bi*** up. 427 winding to 7000 rpm, stalled at 2800 with 411 locker in the rear.
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