??? weight oil in trans

Discussion in 'Softail Models' started by nate, Oct 19, 2008.

  1. nate

    nate Member

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    Does anybody know what the stock weight oil in the trans for a 05 Fat Boy is. My manual just gives me part numbers?
     
  2. glider

    glider Veteran Member

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    Don't know if you are asking what to replace it with or what was in there.
    75/90 or 75/140 depending on your riding and the temps. Hot climates, use the 75/140

    Post the part number you have and we'll tell you what it is.
     
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Re: Please Help? Trans

    Check this out:

    Trans Oil Poll - Harley Davidson Community

    In Hawaii, you should probably go with a 75W-140 gear lube since you may experience higher temps on a regular basis. Do you have the 5-spd OEM tranny? If so, use a premium quality synthetic gear lube that is handy there. Mobil 1 is a great option.

    If you have a 6-spd tranny, try Spectro Heavy Duty Platinum 6-speed Transmission Oil. See:

    Spectro Oils of America - Transmission Gear Oils

    TQ
     
  4. nate

    nate Member

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    ??Trans oil help??

    The Harley part number for the stock trans oil is (99892-84 quart or 99891-84 gallon). I want to switch to Mobil 1 syn. Still running the OEM 5 speed trans. The average temp here in Hawaii is around 90 degrees. 75W-140 or 75/90. My ridding style vary from cruzzin to ridding like I stole it.

    Mahalo (Thank You) N8
     
  5. glider

    glider Veteran Member

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    Re: ??Trans oil help??

    75-140 would be your best bet.