Identifying a M22 while in the car

Discussion in 'Transmission & Driveline Topics' started by Elfmaze, Dec 5, 2017.

  1. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    If he drives it should make a pretty distinctive noise, no?
     
  2. COPO

    COPO Veteran Member Lifetime Gold Member

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    Ontario, Canada
    The M22 will have it's distinctive whine like no other tranny.
     
  3. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    Right! what are the differences in an m22 vs an m21?
     
  4. BigBlock73

    BigBlock73 Veteran Member Lifetime Gold Member

    1,833
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    Jul 10, 2002
    Accord,New York
    Worn out M20 and M21 gears can have the same whine.

    Different angle of the gears
    upload_2017-12-5_15-6-39.jpeg
     
  5. Elfmaze

    Elfmaze Veteran Member

    909
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    May 23, 2002
    Pittsburgh PA
    right, so theoretically a guy selling his car could try passing off a worn M21 for a "rock crusher" to make lemonaid out of lemons
     
  6. Elfmaze

    Elfmaze Veteran Member

    909
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    May 23, 2002
    Pittsburgh PA
    if i did the math theoretically I should be able to tell a m20 from a m21/m22 by speed and rpm match.

    Side note, a Speedo that works intermittently. is that usually a cable, guage, or trans issue?
     
  7. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Oct 3, 1999
    Beavercreek, Ohio, USA
    Yeah. Stick it in first, tach to 2000 rpm (or whatever) and do the math (rear gear, tire size) to determine what the MPH should be with a 2.20 first gear or a 2.56 first gear. You would have to be right on on the tach. It's only a 16% difference in gearing.

    Intermittent speedo could be cable. If it dry or binding, the cable can act like a big long spring. It will wind up and then release and the needle will bounce. The gears in the trans may be botched where a tooth is missing. Or it could be the gauge.
     
  8. COPO

    COPO Veteran Member Lifetime Gold Member

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    Ontario, Canada
    Diff is the angle cut on the gears. The M21/M22 ratio is the same where as the M20 differs in ratio due to the number of teeth.

    M22
    [​IMG]

    M20/M21
    [​IMG]
    [​IMG]

    M22 vs M20/M21
    [​IMG]

    M22
    [​IMG]

    M20
    [​IMG]
     
  9. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    So just gears, no other strength changes such as shafts, etc?
     
  10. COPO

    COPO Veteran Member Lifetime Gold Member

    15,930
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    Sep 15, 1999
    Ontario, Canada
    A worn out M20/M21 will never sound like a M22. Someone
    is smoking some real good chit to think that.

    Put the trans is 2nd gear and remove the side cover and look .
     

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