Transmission lube 99 Road King

Discussion in 'Oil' started by 67hat34c, Feb 23, 2009.

  1. 67hat34c

    67hat34c Active Member

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    Changing co workers oil this week. Going with Amsoil 20/50 in the engine but not sure on transmission.

    What weight of transmission oil to you recommend?

    What about Trans + in the primary -V- Spectro primary lube?

    Bike has less than 10k miles on it and believe original owner used HD synthetic in all 3. Co worker has not changed oil since pruchase a few months ago.
     
  2. glider

    glider Veteran Member

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    GEAR oil in the trans, not engine oil. Mobil 1 75/90 or 75/140 will do fine as well as Spectro if you can get it. Formula+ is a good choice in the primary and spectro makes a good oil for the primary also. Your choice there.
     
  3. 67hat34c

    67hat34c Active Member

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    What is benefit of heavier such as 75/140 adverse to 75/90 or 75/110, all being synthetic. Some talk on other threas about the 75/140 being for 6 speeds since they have both strait and diagonal cut gears.
     
  4. glider

    glider Veteran Member

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    Basically where the bike is being used as far as temps. I saw little difference if any between the 75/90 and 75/140