Ring & Pinion Pattern Second Opinion

Discussion in 'Engine & Drivetrain' started by Dan Acosta, Dec 2, 2018.

  1. Dan Acosta

    Dan Acosta Full Access Member

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    I am looking for some input on this. I have gotten some mixed suggestions so far. I have done quite a bit of adjustments and so far this is the best pattern I can come up with. It is new gears and all new bearings. 2018-11-29 14.27.35.jpg 2018-11-29 14.27.46.jpg
     
  2. Scottydoggs

    Scottydoggs Full Access Member

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    ive not done this myself, but from what ive seen on tv, you got work to do still. contact area needs to be more centered and riding the edge of the ring gear more.

    you are to close to the inside still.

    you do the pinion side right? from what ive seen you use the old crush sleeve and get it all aligned right, then take it all apart again noting all your shims and put the new pinion seal and parts in.

    found a vid on it real fast, shows the pinion being off some.

     
  3. Dan Acosta

    Dan Acosta Full Access Member

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    I have seen a few videos where they suggest the pinion movement, changes the depth of the pinion in the teeth of the ring (closer to the face or the root), Also that is more important than the toe/heel location. I was under the impression that being a littel closer to the toe allows for the expansion of the contact pattern under load. A little confused.
     
  4. drakon543

    drakon543 Full Access Member

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    bbbbaaaahhhh just bolt that sucker up pack it full of bananas drive around the block and top it off with 120w and call it a day.
    ((so captain obvious doesn't try to strike this is clearly meant as poor humor please never so this))
     
  5. Erickk120

    Erickk120 Full Access Member

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    its been a while since I've touched one but to me it looks like the pattern is too deep, I'm no gear expert either but I don't really like how the drive side looks, its to far down the toe, and the coast is just hugging the root. Whats your backlash set to? whats the pinion depth atm? I would make sure you are within spec backlash first and then adjust the depth after a pattern check, remove a few 2-4 thou at a time that way you can see the gradual shift. Here is what mine ended up looking like at .034 pinion depth can't recall the backlash but it was tight as called by the gear manufacturer. somewhere between 3-6 thou some might ask for 6-10 really depends on the manufacturer.


    deep.PNG 20170412_223056.jpg 20170412_223109.jpg
     
    Last edited: Dec 2, 2018
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  6. Dan Acosta

    Dan Acosta Full Access Member

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    By too deep, do you mean to deep in the housing or too deep into the gear? Backlash is at .007
     
  7. Erickk120

    Erickk120 Full Access Member

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    By deep I meant deep into the root of the coast, it looks like the coast has a moon shape kind of like a C shape, they are supposed to be kind of oval shaped with no hard edges, If you look at the negatives in the non coated tooth you can see it more clearly you can see how it printed C shaped in the tooth. To me it looks like the pattern image I posted above which is too deep or close to the ring gear/housing same thing, need to decrease pinion shim and check what it looks after.
     
    Last edited: Dec 3, 2018
  8. Erickk120

    Erickk120 Full Access Member

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    This is what the opposite will look like when you are too shallow/too far away same thing, you will get a reversed C shape, This was a ford 8.8 but the principle is the same. If you look at the drive you can see it perfectly in the negative teeth that haven't been coated.
    sorry about the tripple post, website is having issues for me
    20180612_204618_1528854293246.jpg 20180612_204627_1528854305011.jpg Contact_Patterns_-_Exploded_views_-_Installation_Specs_-_Break-0001-760x721.jpg
     
    Last edited: Dec 3, 2018
  9. Dan Acosta

    Dan Acosta Full Access Member

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    Current Pinion shim is .033 while the one on the oem gears is .020. The patterns are fairly rounded, and I think the appearance of closeness to the root is a lighting issue. I have been up and down with the pinion shims, and the patterns are fairly even (coast & drive). Once I go either way, the patterns move in opposite directions (towards the toe & heel). I may try taking a few out again before I take it to a pro. I will post pics if I do. It just seems the more I take out, I start to turn the ring by the tit/top of the pinion.
     
  10. Erickk120

    Erickk120 Full Access Member

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    When you removed pinion shim did the drive move up towards the heel side and coast to the toe end? and or have you tried tightening the backlash to 4 and see how it affects the pattern? I'm asking this because I believe you got 2 cut gears and those can be run tighter. I remember having problems getting a proper pattern with my first set until I tightened it between 4-6 thou. As for your current pattern does it shift up if you increase its backlash? I would say its pretty close, I'm just not comfortable with how little contact there is in the drive side. You can probably PM 01ssreda4 and ask his opinion as he knows more than I ever will when it comes to this stuff. What spec does your gear manufacturer recommend and who is it. 029 shim is what I normally start with and it tends to be a little bit shallow most of the times, then I adjust from there, from the few GM10 bolts I've put together it seems like they like it somewhere around the .030's my Tahoe ended with .034 another 10 bolt was just below that I believe. Rebuilding a rear end is frustrating until you get the hang of how things go together, after that its trial and error.
     
    Last edited: Dec 3, 2018

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