Merak clutch throw out bearing | FerrariChat

Merak clutch throw out bearing

Discussion in 'Maserati' started by Zortrax, May 27, 2017.

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  1. Zortrax

    Zortrax Rookie

    May 27, 2017
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    #1 Zortrax, May 27, 2017
    I have the transmission out of my 1979 Merak SS at the moment to replace the clutch throw out bearing or thrust bearing as some call it. It is the carbon disc style bearing. I purchased the bearing from MIE but no one really knows the correct way to install it into the steel holder. It appears to brittle to press in cold. I have heard that the steel holder should be heated to cherry red and then the carbon bearing inserted. I can do that but the difference between the inside diameter of the holder and out side diameter of the carbon disc is .007 inch.To me that is a significant amount. I am wondering if the bearing will be damaged or break once the steel carrier cools and shrinks back to its original size. Any information will be appreciated.

    Regards
     
  2. Zortrax

    Zortrax Rookie

    May 27, 2017
    5
    #2 Zortrax, May 28, 2017
    I have the transmission out of my 1979 Merak SS at the moment to replace the clutch throw out bearing or thrust bearing as some call it. It is the carbon disc style bearing. I purchased the bearing from MIE but no one really knows the correct way to install it into the steel holder. It appears to brittle to press in cold. I have heard that the steel holder should be heated to cherry red and then the carbon bearing inserted. That is possible but the difference between the inside diameter of the holder and out side diameter of the carbon disc is .007 inch.To me that is a significant amount. I am wondering if the bearing will be damaged or break once the steel carrier cools and shrinks back to its original size. Any information will be appreciated.
    Regards
     
  3. staatsof

    staatsof Nine Time F1 World Champ
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    #3 staatsof, May 28, 2017
    Last edited: May 28, 2017
  4. Zortrax

    Zortrax Rookie

    May 27, 2017
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    #4 Zortrax, May 28, 2017
    That's correct. They have not had the opportunity to do this at there shop. In there literature it states it is a press in affair. I have pressed in bearings before but only in steel. The size difference is usually only .002 - .003 inch. In this case I have a size difference of .007 inch.
     
  5. thecarnut

    thecarnut F1 Rookie
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    #5 thecarnut, May 28, 2017
    Last edited by a moderator: Sep 7, 2017
    Years ago I had to change the throw out bearing on a Merak SS and I recall new bearings were not available. The graphite material is the same size as that used on Jaguar e-types therefore I removed the graphite from a new Jaguar bearing I had laying around.

    Put the graphite in the freezer for a day. Heated Merak's metal bearing carrier and tapped the graphite with a rubber hammer. I do not recall it being too difficult to insert.

    Perhaps the graphite MIE is selling is a bit too large. I measured a Jaguar bearing for comparison.

    Ivan
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  6. Zortrax

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    May 27, 2017
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    #6 Zortrax, May 28, 2017
    Thanks for responding. My bearing is 71.475mm. The bearing carrier is 71.272

    Harry
     
  7. staatsof

    staatsof Nine Time F1 World Champ
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    #7 staatsof, May 29, 2017
    I'm coming up with 8 thousandths. Perhaps the carbon compresses a bit and that's why. I agree that you need to look into this more in order to be comfortable. It's also the first time I realized that the Merak's TO bearing is so different from the rest of the Maseratis of that era. I used one from a Jensen Healey for my Bora. Too bad. Try the Merak group or the Yahoo group I listed. The guy who runs that is an engineer. Someone may have upgraded this to a BB style?

    Bob S.
     
  8. boralogist

    boralogist Formula Junior

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    #8 boralogist, May 29, 2017
    Not sure why MIE bearing is presenting an issue but this is what you need:

    BEARING, RELEASE, STOCK TYPE, CARBON THROW OUT BEARING OE, MGA, MGTC,TD,TF for 1957 MG MGA. #GRB103X

    Regards.
     
  9. staatsof

    staatsof Nine Time F1 World Champ
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    #9 staatsof, May 29, 2017
    Apparently it's not the same as the Bora. :)
     
  10. gcmerak

    gcmerak Formula 3

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    #10 gcmerak, May 30, 2017
    Hi Harry

    M.G. Email was sent to you a few days ago. The throw out bearing has already been installed by one of the Merak Group members, just recently as a matter of fact. It was pressed in with a block of wood sandwiched between the press and carbon insert. No heating required. It is a perfect fit in.

    Harry, nothing to it, just do it. :)

    Ciao,
    George
     
  11. Zortrax

    Zortrax Rookie

    May 27, 2017
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    #11 Zortrax, Jun 5, 2017
    Success. Took the advice of more experienced gearheads than myself. After making sure the bearing holder was perfectly level I pressed in the bearing cold. I have done a lot of machining and have pressed in steel bearings and bronze bushings, but never carbon. The rule of thumb is usually .001" per 1 " in diameter. Obviously the carbon bearing disc has a very different dynamic. As .008 "difference with in a 2&3/4 " diameter was not a problem for it at all.
    Thanks for all the input.
    Regards , Harry.
     

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