Throw out bearing to finger clearance

Discussion in 'PSI Superchargers Tech Questions' started by aafa760, Jul 30, 2018.

  1. aafa760

    aafa760 Member

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    Pedal clutch guys with the throwout all the way back against the Collar how much distance do you
    like to see between fingers and TB? 1/2 " 3/4"

    Bryan
     
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  2. rb0804

    rb0804 Active Member

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    .100” would be the minimum that I would run. If you call a manufacturer, they will probably tell you .250”. The biggest thing is to have some sort of spring getup to aide in a clean release of the fingers. Some like external ones off the linkage or bell crank but you could also use the AFT throw out bearing that has the spring built into it. Make sure your linkage is good and sturdy, I have fixed many a clutch issues that were caused by weak, flexing, binding linkage. Make sure to take your measurements with the thickest clutch pack you will be running, nothing worse than being at the track and hossin’ in a new pack and the can won’t fit on cause when you took the measurements all the discs and floaters were wore out at .280” each. Good luck.
     
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  3. jay70cuda

    jay70cuda Well-Known Member

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    The problem with having .500 or more is the pedal travels so far that in a launch when you release the clutch the pedal will move another 3-4 of swing. More than likely if you have that much you will need to put a stop on the pedal as well. Nothing worse than reaching for a clutch pedal and it not being where you think it is
     
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  4. aafa760

    aafa760 Member

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    Jay I put in new collar for clutch shaft sensor it is .013 longer in TB area it did not allow the bearing to move back far enough let weight to move arms ran on static only 8 k rpm max. It realeased clutch ok just no centrifical help
     
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  5. aafa760

    aafa760 Member

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    Yea Jay understand that one. It is .dragster so the pedal can return to far without my stop in it. The new collar is .013 longer in the TB area than old one. It released clutch but did not allow centrifical apply. Drag racing game of thousands not inches.
     
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  6. Bob Meyer

    Bob Meyer Comp Eliminator

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    A dragster with floating motor mounts (half caps w/ T-bolt clamps) should run .300 clearance, finger tip to bearing face. Being the clutch grunt for over 15 years, gives you ideas for simplicity.....
    I used an old 5/16" Hex wrench (not made by Allen), rolled 24" of silver tape on the end into a sort of tube, (in case you dropped it in the can), then checked clearance using that as a go/ no go gauge. Same type of tool as your 3/16" hex spring adjuster, without sawing off the long end.
     
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    Mark Leigh likes this.
  7. aafa760

    aafa760 Member

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    Hey Bob once again great Idea
    Simple to make.
    Thanks again.
     
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