I know this has been talked about, but searched and still not sure!!!.
I have been using syn 3 all three holes . Engine and tranny has had more noise than normal. I want to try Mobil 1, can it go in all three holes?

 

20/50 in all three if ya want, what I run except for I went to Redline heavy syn in the trans. Like Mobil better than most oils out there but its all still just an opinion

 

I would go with something a little heavier in the tranny.

 

I am new to this too and reading all the info is quite confusing, so if you don't mind I am going to throw a question in too.

I know that some people are using M1 15w50 instead of the M1 V-Twin 20w50, but I am ASSuming that the 15w50 can only go in the motor and not the Primary or Tranny? Or can it be used in all three holes like the M1 V-Twin 20w50?

Phil

 

Engine oil CAN go in all three holes but it is not the best choice even though Harley claims their Syn3 can do the job. You want slippery in the engine but the primary requires an oil that lets the clutch NOT slip. The transmission is a gear box and best for it is a gear oil. Any of the V-twin synthetic engine oils is good in the engine, made to withstand the heat. Harley's own Formula Plus is good in the primary, so is Redline V-twin Primary etc. This forum names many good tranny fluids. I use Redline V-twin Transmission with Shockproof. Great stuff but again there are many good choices. Boils down to personal choice.

 

nuts, wrong thread! I thought it said exchanging fluids.......

 

not sure..I use Syn 3 in all 3..no problems...just wanted to chime in and say nice 100th FLHT..it's rare to see them!

 

thanks, But more important ,{Thank You for your service}

 

when i bought my 2006 flhri a few months ago, it had syn2 in all three holes. my motor had all kinda crazy noises and the trans was real clunky. i switched to harley 20w50 for the engine,formula plus for the primary and bel-ray gear oil for the tranny. noises are gone all together.

head

 

Try a new compensator.