Royal Purple gear oil for me. Shifts a lot smoother now.'06 five speed.

 

Thoughts about using a 15w-50 synthetic oil in a 2009 6 speed transmission? Kinda like a jungle with scattered info. Some say GL-5 rated oils (75w-90/140)are not neccessary and maybe too much. Amsoil is the only company I see that rates their 20w-50 m/c oil as GL-1. Mobile says the 20w-50 m/c M1 syn is better than their 75w-90 gear lube, as does Amsoil. Lastly, the viscosity chart would show a 15w-50 oil actually closer in spec to a 75w-90 gear oil than a 20w-50 oil. Reason is I can get a qt of M1 15w-50 for $5 from a buddy. Heck, I'm sure it would be just fine but just throwing out for opinions...
http://www.teamrip.com/viscosity_chart.html

 

I switched to Amsoil 20w50 at 3200 miles. 5000 mile is coming due so Ill do 20w50 in two holes and try Amsoil 75w90 in tranny. I believe in the porduct an dwill do just fine. A lot of mix reviews and I respect everyones opinions. Its all a matter of choice an dwhat works for you and the bike. Ride on and hard.

 

15w-50/tranny answer here:
https://www.mobiloil.com/USA-English...Davidsons.aspx

 

Just switched to Redline with shockproof, had HD synthetic in before. Redline is heads and shoulders better, smoother shifting, better performance.

 

Hey all, new to the site and to harleys,

Going to do my first service on my 08 rocker c,bought it used and it is due for the 10,000 mile service.

Was going to run 20/50 amsoil in all three holes but after reading on here it looks like most people are using gear oil in the tranny.

Does anyone know if this is recommended by the factory or will it void a extended warranty?

Thanks,Daniel

 

Use in confidence. It exceeds OEM requirements. FWIW, the Moco will only recommend their own products such as Syn3 in all holes (Amsoil a much better product) or Formula+ in the primary/transmission.

 

Anytime you are dealing with warranties, anything other than what the factory recommends can cause you issues if you have a claim.

It seems you have a decision to make.

 

Thanks for the replies,called the dealer and they said amsoil is ok,they were going to check out using gear oil in the trans,still waiting lol. Going to give them a call again tomorrow.

 

Has anyone here used the ultima synthetic trans fluid?