Fluid Question

Discussion in 'Transmission' started by AndyRK, Jan 29, 2011.

  1. AndyRK

    AndyRK New Member

    for my first diy tranny fluid change since I bought my 05 Road King last year, I bought Lucas 85/140. I did alot of reading since its my first time, many others were mentioned. Other recommendations I came across were Mobil 1 75/90 or 75/140. These were my only choices at the store I was at anyways, so I got the thicker one. I havent done the fluid change yet, and decided to check the lucas website to compare the one I got to anything else they may have. The one I bought is the "Heavy Duty Gear Oil" 85w-140 and it has a picture of a 18wheeler on the front, it doesnt say synthetic. But their website has a synthetic gear oil 75w-140, which would be better?
    Last edited by a moderator: Jan 29, 2011
  2. wilks3

    wilks3 Junior Member

    Of those two, the synthetic 75W-140 would be my choice. That being said, I used RedLine Heavy Shockproof 75W-140, trans shifts great. I'm sure you will get other tips on different oils. Check out the tranny oil section for the many different choices.
  3. AndyRK

    AndyRK New Member

    Thanks for the quick reply... I did hear about RedLine also but I might have to buy that online, and I probably will since I see that I dont even have the correct allen wrench for the trannys dipstick, so the job is cancelled for today.
  4. Jack Klarich

    Jack Klarich Expert Member

    Trans Oil Poll - Harley Davidson Community have a look here, some interesting reading
  5. Iceman24

    Iceman24 Well-Known Member

    I'd return the HD 75/140 & get synth 75/140...better choice for m/c.
  6. AndyRK

    AndyRK New Member

    well, I returned the Lucas oil which had a heavy weight but wasnt synthetic and I bought the Mobil 1 75W90 synthetic only to return it for the 75w140 which is supposed to do better in hot climates (im in south FL). I did all my fluids today with the forementioned oil in the tranny and Mobil 1 20W50 V-twin in my crank and primary. It got late and I have to wait till tomorrow to refill to level after a quick warmup ride, Ill post if I notice any difference in performance later. Although I dont know what my bike had in it before, but since I bought from HD dealer it might have had syn3 in all holes which is was they recommended when I went to them for my new oil filter and o-rings. Thanks for the help.. im new here but it looks like Ill be using these forums often with such gurus at hand :D
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator