Hi ,I'm going to be changing the oil in my 2 fatboys soon and need your opinion, I'm thinking of using amsoil synthetic 20w50 for the motor, spectro heavy duty primary chaincase oil for the primary and spectro platinum heavy duty synthetic GL-5 6- speed gear oil 75w140 in the transmission. Is it worth the money for the 20 dollar a quart for the transmission or is there something better. I currenty have amsoil 20w50 synthetic in all three holes. Any advice would be great so I can get the fluids changed soon. THANKS

 

I use Amsoil in all 3 holes. 20w-50 in motor and primary and Severe Gear 75w140 in trans since first fluid changes. No problems.

 

You will get tons of opinions on this. I like amsoil 20 x 50 in the motor , redline mtl in the primary, redline heavy shock in the tranny.

 

I thought there would be a lot of opinions, I guess what i'm really wondering is if there is an oil that will work better in the transmission and primary to help shift better/smoother and for the wife to beable to find neutraul better. THANKS

 

Goblish,
For what it's worth, these are my personal preferences.
Mobil 1 20w 50 synthetic in the crankcase $9.00/qt. X 3qts
Redline heavy shock proof in the tranny, $11.50/qt
Redline MTL in the primary $10.50/qt.
I buy the Redline products from Racer Parts Wholesale.
I believe they still are, or used to be an HDforum sponsor.
As of last year, I know if I mentioned HDforums to them I got a 10% discount.
I don't know if this is still in effect.

 

I'm using full synthetic 20W50 in all three holes.

 

I am using the Spectro oil in my transmission. Its not bad but its not the day/night difference that led me to spend the $20 bucks.
I am going to try the Redline next.
MikeM

 

Try Redline shockproof heavy in the tranny and Dexron III ATF in the primary and see if she likes it.

 

I've found that having the Clutch adjusted properly takes care of shifting/finding neutral issues. Then you just use whatever brand of oil that makes you feel good.

 

Wow,$20 for the Spectro tranny fluid.Thought I was going to puke when I saw the Redline Heavy Shockproof (which I use)priced to $15.50!

Last time I bought it, it was $13.50.

You can save some cash by using automotive tranny fluid or regular mc oil like Valvoline 20/50 for the primary.