What oil do you use in your tranny? Mobil1 75w90? Syn3?

 

Syn3 in all 3 holes.

 

Red line V-twin transmission oil
Syn III in the engine
Type F ATF in the primary

 

+1 on Red Line

 

Redline shockproof heavy in da tranny


Nuff Said!

 

Amsoil 75W-110, Belray Transmission or 85W-140, Spectro Platinum 75W-140 Transmission or Redline Shockproof Heavy are some of the best choices on the market for your transmission. 20W-50 motor oil will work, but it's not the "best" fluid for the application.

 

With my 09 and the notorious 5th gear whine, I have found the Amsoil Severe Gear 75-110 keeps it quiet and shifting smoothly.

 

Redline Shockproof. What a difference it made too.

 

I was using Syn 3 in all three holes since 500 mile service, but was never really happy. So for the 15K service I put in Mobil 1 V-Twin 20-50 and Mobil 75-90 in the tranny and didn't notice a big difference. So, I just had the 20K service done and I put Syn 3 back in the engine and HD Formula + in the primary and tranny.
I'm now will always use HD Formula + in the primary and tranny. I really noticed a difference. Not sure what I'll use in the engine next.

 

Many will try several different oils, most will end up with the above.