Mobile 1 75w90 or 75w140?

Discussion in 'Transmission' started by softail41, Mar 1, 2012.

  1. softail41

    softail41 Active Member

    I have a 1000 mile service coming up this weekend on my 2012 FLSTC. I have read all the oil polls on here as well as a lot of other great info and have decided to go with:

    Mobile 1 V-Twin 20-50 in Engine
    Harley Formula +1 in the Primary

    Before I go any further, I realize that Spectro and Redline are very popular in trannys on this site, however, it is not readily available in my area. So I have decided to go with Mobile 1 gear oil.

    So, the question is - Do I go with 75w90 or the 140 wieght? I live in Southern Alabama and the temperatures here are quite high in the summer (by the way it is 73 outside as I write this!) and I would tend to believe that the 140 would be better but wanted to get the opinion of the great minds on this site.
  2. ironmark

    ironmark Junior Member

    I have used both the 75w90 and the 75w140 and both are good products and served me well. I use to change from the 75w90 to the 75w140 for summer riding but now I just stay with the 75w140 all year around. I get my tranny oil at AutoZone and I get the Mobil 1 75w90 for around $10 a qt and the 75w140 is about $18 a qt. I now use Valvoline 75w140 full synthetic gear lube in my tranny and I also get that at AutoZone and it is around $12 a qt, so you may want to go with the Valvoline because it is just as good as the Mobil 1 75w140 and it cost less.
  3. Breeze3at

    Breeze3at Well-Known Member

    I put Mobil1 75w90 in my '07 transmission at the initial change. I noticed less "clunk" when changing gears. Next, I changed to Spectro 6 speed Platinum (or somethin' like that). It works well also, but I can't say I noticed any difference at all from the Mobile1. I also like HD formula + in the primary.
    Last edited: Mar 1, 2012
  4. Iceman24

    Iceman24 Well-Known Member

    Down there - the heavier grade GO (75W/140) would be best...order your Spectro Oil online...that's what I did.
  5. softail41

    softail41 Active Member

    Tank, thank you for the info. Wow! You have to be the first person on here that recommends engine oil in the tranny! I like the fact that it is cheaper for sure....However, maybe you can explain this: Under the Amsoil link you posted, at the bottom there is a cross reference sheet that says:

    Harley Davidson Part # AMSOIL PRODUCT
    99892-84 Transmission Lube SVT 75W-110 Gear Lube
    SVO 75W-140 Gear Lube
    MCS SAE 60 Engine Oil

    Am I missing something, or is this recommending SVT, SVO, (gear lube), MCS (Engine oil) in this priority?

    Not trying to start an argument here, just trying to understand.

    This was my first choice, but I'm kinda in a bind....the weather is good, I need a service done, and I don't want to wait on shipping or pay for 2 day shipping. I WANT TO RIDE!!!!

    I may switch over in the future. Tank does not recommend Gear Lube in the tranny and he is a dealer, so I am trying to figure out the right way to go.

    Oops! Sorry about the caps in the previous post...I wasn't yelling, promise :s
    Last edited by a moderator: Mar 1, 2012
  6. softail41

    softail41 Active Member

    Thank you for the reply. I think that cleared things up a bit! I also read on this forum that GL-5 was not good for "yellow metals" and I guess there is still some question wheather our trannys have any of this type metal in there?

    Thank you again for your time and info.
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    I live in the Houston Texas area which may have a similar climate to yours in Alabama. I use the following in my engine, tranny and Primary:

    Engine: FULL synthetic 20W50 VTwin engine oil
    Tranny: FULL snythetic 75W140 GL-5 gear lube
    Primary: Fit-for-purpose chaincase/wet clutch lubricant (like HD Formula + or Spectro Primary, Redline Primary, etc.)

    I would not hesitate to recommend those types of products for our bikes.

    In my case, that is Mobil 1 VTwin 20W50 engine oil, Spectro Heavy Duty Platinum 6-speed Transmission Oil, Spectro Heavy Duty Primary Chaincase Oil

  8. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

    I like Bel-Ray 15-50 for the motor.
    Spectro 75-140 GL5 for the trans.
    And I have tried many oils for the primary,but the cheapest 20-50 dino oil works fine for me with the least amount of drag.
  9. itisi

    itisi Member

    Mobil One V Twin in the Crank
    HD + in the primary (Dino oil is fine here)
    Redline in the Tranny.

    I have tried Mobil One, Spectro and Redline in the Tranny. All I am sure provide more than enough protection, But I can say without hesitation that Redline is the only oil in the tranny that I noticed an IMMEDIATE improvement with smoother shifting as well as quietness. I am sold on it for the Tranny. I might go with it in the crank as well. :s
  10. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

    I found that I had too much valve train noise with the Mobil-1
    The Bell-Ray all but eliminated it.