trying to be postive in Maintaince and the need to stay on top of it, I still have questions on oils after reading all the information??? After reading a lot of posts in several forums, I think Amsoil per say is among the leaders overall, But after reading several Indy post on oils I believe (in my opinion) that Mobil 1 V-Twin is also and more easily found. It seems that the SYN3 falls just a little behind both of them in some areas.
ALSO I am not sure in the new 96in B motor is better off putting gear oil (75-90) Mobil 1 syn (etc) in the transmission over20-50 syn oils??, Maybe the 88in and older Harleys needed it more than the new 96in,? as my owners manual does'nt say much...
Up till now I have run only Harley SYN-3 in all three,with 9.4k on it as Per Dealership recomended it on the 1K and 5K checkups.!
Spring 08 and ready for the 10k checkup and thinking about different oils in the holes...
New idea is:::::
Mobil 1 V Twin, (20-50) in the motor...
Keeping the Syn 3, (20 -50) in the primary because the last 9.4 k has had it (only 1st K had factory dyno oil in it)...
Mobil1 syn75-90 in the tranmission
Thanks to all who help make the best!!!!! BETTER.....

 

Any good synthetic in the engine, to include Mobil 1, Amsoil, Redline, Syn 3, Royal Purple, Spectro, et.al.
At the end of the day none is really "better" than the others and all will lubricate the engine more than adequately.

You can use M1 V-Twin in the primary, but it's a tremendous waste of money. It's a low-tech, low stress environment and is more than adequately lubricated with 10W-40 or 20W-50 dino engine oil, a 15W-40 HDEO like Rotella, ATF, or H-D Formula+. The key to a healthy primary is more keyed to frequent changes vice oil selection due to the fact that it's not filtered. I change the primary oil every time I change the engine oil, i.e. every 4k-5k miles.

Transmission- any dino or synthetic gear oil. You can use 20W-50 engine oil, but a quart of good gear oil is only about half the cost of a quart of M1 V-Twin or Syn 3 and will more than adequately lube the transmission.

 

I tried syn gear oil in the trans of my '03 ultra and had 2 issues. 1) when the bike got hot and when stopped at a light you could smell it. at first I thought the bike was on fire, but it was just hot gear oil.2) my speed sensor in the trans grew a big fuzzy ball of schmutz on it and the speedo quit working, until I pulled it out and cleaned it. went back to amsoil 20/50 . shifts smooth and is a gl1 rated oil and thats all you need. anything more is overkill and just makes you feel better. don't think the trans cares.,,

 

Did you try amsoil gear oil?

 

This would be a good combination as Syn3 has no moly in it (<5ppm) to possibly cause clutch slippage. You will like the gear oil better and it will go the 15-20,000 miles.

 

no I used castrol synthetic 75/90 wt gear oil. wasn't impressed and didn't notice any change in shifting. not that any was needed. and for what they sell it and mobil 1 for I cant justify the expence. amsoil 20/50 works fine for me. the trans shifts fine and is quiet no issues.

Did you try amsoil gear oil?
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Well that is a new one for me. The amsoil 75w110 is supposed to be great stuff. I don't know about the smell though. Maybe the sulphur smell from the gear lube coming out of your trans vent?