Mobil one question
Road Master
Joined: Jan 2013
Posts: 756
Likes: 2
From: Virginia
Sounds like he's saying he wouldn't use it in his trans. At my 1000 mi I put it in all 3. I kept reading on here how happy a lot of users were with Redline oil with shockproof so I thought I would try it at 5000. Told myself I was not going to get caught up in all the hoop la over something I didn't think could make that much difference. Well after almost 500 miles on the change it does seem to make quite a difference. Quieter and smoother so I'll be staying with it for the trans.
Seasoned HDF Member
Joined: May 2008
Posts: 21,026
Likes: 12,548
From: South Carolina
Many transmissions use motor oil, transmissions that deal with a lot more horsepower than most Harleys put out, Japanese bikes in particular have used motor oil in the transmissions since day one.
Ever heard of a Harley transmission gear wearing out prematurely because it used Mobil 1?
Mobil 1 will work fine in a Harley transmission.
Ever heard of a Harley transmission gear wearing out prematurely because it used Mobil 1?
Mobil 1 will work fine in a Harley transmission.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,897
From: Bedford UK
I'm always amused by threads that ask questions like this. Are we all wiser and better informed than the motor manufacturers? Would I put engine oil in my auto transmission? Why do oil manufacturers produce a dedicated oil for each hole? Why are there three holes in the first place? Why do so many questions get asked about the darned stuff? Why is it so difficult to follow a vehicle manufacturer's recommendations? 
Would I put the same stuff in all three holes? Hell no!
Can we move on.......
Would I put the same stuff in all three holes? Hell no!
Can we move on.......
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Road Captain
Joined: Feb 2011
Posts: 670
Likes: 22
From: Umatilla, Fl
Just remember everyone here is an expert. I would suggest doing research on this site and others and in the end make your own decision. What pushed me over the edge is reading off the Mobil website that you can utilize their oil in all 3 holes. Seeing how they would put that in print opens them up to some large liability issues if their oil didn't satisfy all of the minimum requirements. But then that is just me and I'm not an expert.
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Goto your local Harley Davidson dealer, ask them if you get the synthetic HD Screamin' Eagle 20W-50 oil can it be put in the trans too, They will tell you yes... So I went to Auto Zone and got the Mobil Vtwin Synthetic and works fine, But hey I am no Petro Engineer....
Road Warrior
Joined: Apr 2011
Posts: 1,365
Likes: 9
From: Greensboro, NC
Like someone else already said, Just about every other brand of motorcycle uses a shared sump, so the trans if lubed with motor oil, with no ill effects over 200K miles. Just think, all those GW go over 200K with 8K oil changes and a shared sump.