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Pinion Nut Tightening Question

Discussion in 'Differential & Driveline' started by trukman1, Jun 10, 2020.

  1. trukman1

    trukman1 Full Access Member

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    I replaced the seal on my '88 K5 10-Bolt and, like an idiot, forgot to count the threads before removing the pinion nut. How do I get it back on to the right place without screwing up the pinion depth setting? Or am I screwed?

    ETA: Pinion Seal
     
    MrMarty51 likes this.
  2. highdesertrange

    highdesertrange Full Access Member

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    you can do it by feel, but if you are not familiar with doing that you will not have much of a chance of getting it right.

    you can use a dial indicator but on a used ring and pinion without taking readings first you are just guessing.

    what you are shooting for is the yoke just touching the crush sleeve no more no less.

    you could buy a new crush sleeve and redo it. but again on a used ring and pinion with a wear pattern already this doesn't always work.

    highdesertranger
     
  3. trukman1

    trukman1 Full Access Member

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    Wow! I was really hoping for a simple "why didn't I think of that" fix. Guess I'll take it to the local diff shop pro and pay someone who knows what their doing. Thanks for the reply.
     
  4. trukman1

    trukman1 Full Access Member

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    Heck, I might just pull the trigger on a Yukon Posi unit and have it redone.

    Any suggestions on the "go to" for 10 bolt posi units?

    And should I try to find some 30-spline axles or are 28-splines okay for street driving? I'm too old and too crippled to go off road.
     
  5. Blue Ox

    Blue Ox Turning Diesel Fuel Into Fun

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    Pinion depth is set by shims, so it's not going to change. What you're concerned with is pinion bearing preload. That's set by the crush collar between the bearings. It takes a fair amount of torque to uh,... crush.. the crush collar. Maybe somebody here will chime in with a number, but I'd just Loctite the [email protected] out of it and tighten it up. Probably 80 to 100 lb/ft.

    Of course, this all assumes it was correct before and that your leak was only due to a tired seal and not bearing play. YMMV.
     
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  6. dhenderz

    dhenderz Full Access Member

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    Blue Ox has it correct. But standard procedure calls for replacing the crush sleeve, it is not reusable. Yes, people do it all the time. Sometimes it works, for a while. And yes, crushing the sleeve takes an enormous amount of torque. And it only takes a fraction of a rotation too far to get too much preload, which will destroy the pinion bearings. It does take some practice.
     
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  7. MrMarty51

    MrMarty51 Full Access Member

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    And, I have added a shim on top of the crushed crush sleeve then retorqued and adjusted from there.
     
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  8. Blue Ox

    Blue Ox Turning Diesel Fuel Into Fun

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    You guys are right, I should have stipulated that the right way to do it is to measure and reset the preload. But around here that seems like asking for a kidney. And to be fair, it does involve disassembling the whole rear and having the right tools to do it, so I can see why people are looking for a shortcut.
     
  9. Curt

    Curt Junior Member

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    Going forward,before loosing the pinion nut,use a paint marker across the nut and pinion shaft.May also record or at lease get a close estimate how much torque required to loosen.
     
  10. Octane

    Octane Full Access Member

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    I did the preload by feel and my pinion nut torque I was told should be about 200 ft lbs.Torqued that sucker close to that and all is well Been driving it for two months now with no issues.1977 k10
     
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  11. Madhorn

    Madhorn Full Access Member

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    Did the same on my 12 bolt. Torqued at 160. No issues.
     
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  12. trukman1

    trukman1 Full Access Member

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    Thanks guys, I'm going to try torquing it to 160-200 lb ft. (In my condition it'll be however much I can manage). If it eats it I'll throw in a posi unit. :banana-mario:
     
  13. Ricko1966

    Ricko1966 Full Access Member

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    Putting more torque on an already crushed crush sleeve is going to crush it more putting too much preload on the bearings.This isn't 100 percent right but how I have done it cheater style I put a piece of pipe inside the crush sleeve and smack it with a hammer in a few spots to stretch the sleeve back out a little then crush it again by feel until all clearance is gone then baby steps until I can feel turning resistance, like doing a wheel brg by feel, no final torque spec., spec is where preload is right. Better would be use a solid shim from Ratech instead of the crush sleeve.I don't have the web address or I'd put it up for you.The Ratech solid shim kit is pretty cool in that it is infinitely reusable and can be torqued to a given spec.
     
    Last edited: Jun 15, 2020
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