The Mobil-1 75w-90 Gear Oil is easy to find and works very well IMO. But for those botique"ers try Amsoil 75w-90. Don't go heaver than 90 on the top number because of the clutch. BT"s can run even heavier weights because of the seperate clutch.

 

If ya cant find the gear oil for some reason check in the boating section of walmart as they have Lubrimatic, Rotella, Mobil etc. at times back there for outboard gear oil. I've been using Rotella since I could not find anything else and it works fine, I've found that they have 75/90 85/90 90/140 if I recall.
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As for Amsoil, I tried it&nbsp\\;\\\\\\; once in the Primary as well as engine and don't believe the hype...&nbsp\\;\\\\\\;its all $$ and no better (actaully thinner) than generic synthetics. Using Castrol blend 20/50 now and still have Rotella in the primary.

 

I got a Lopers, an AutoZone, Sucker Punch Sallys (buddies in the shop), Ramjet Racing, MMI, and countless stealers within half an hour...I should be able to find it somewheres.&nbsp\\;\\\\\\; But thanks for the tip .&nbsp\\;\\\\\\; Gotta remember that on road trips!

EDIT:&nbsp\\; Actually just got an email from a buddy bout using aircraft oil, too.&nbsp\\; No specifics yet, but he runs it in all his bikes.

 

BAD IDEA. Aircraft oils do not contain detergents. [:@]

 

Amsoil 20W50 in the motor.&nbsp\\; Mobil 1 Gear 75w90 in the primary.&nbsp\\; No problems.

 

20/50 engine/primary....75/90 tranny

 

i havent done an oil change on my bike yet, but i'm planning on using synthetic.

 

20W50 lucas w/ 20 oz of the oil additive in the motor, 20/50 primary, mobile 1 75/90 gear in trans

 

Since when does HD not recommend using the same stuff (Syn3) in both holes? Granted Formula+ isn't for engines, but why not? I don't smell any sulfur in it. And that's the concern with gear oils being used in an engine - the moisture will combine with the sulfur to form sulfuric acid.

 

In hotter temps you guys might want to try straight 60w SYN&nbsp\\;in the motor. I've been using it for the last month or so and the bike seems to be running cooler. I've been using a product made by Klotz for american V-twins
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Mobil1 75w-90 in the tranny every time