20w50syn or Amsoil 75w90 for trans in 06 sportster

I saw where 20w50syn was recommended for my sportsters trans and primary, but have also heard and read that the Amsoil 75w90 (?) works better and quiets things down a little more as well as smoother shifting, which isn't a problem anyway. Onlt 6400 miles on this sportster. "Preciate the opinions and advice. Thanks.

A 75-90 gear oil would be better than engine oil in your tranny/primary.... IMO....but you have to run a gear oil that is also suitable for wet clutches(limited slip additive pak)....HD's formula+ works well...Sporty trannies,clutch and primary share the same oil...

I am using HD's primary oil non synthetic and I love it....

Yea, this sportster is kinda new territory to me...Still like brand new, low miles and far as I know has the original fluid in the primary, tranny. I know about the Formula + but was seeking some opinions on other fluids, since the nearest dealer is down the road a good ride. And I try to avoid the stealership as much as possibel. I'll probably break down and make a trip to the dealer to pick a quart or two up. I've heard a lot of good things about the formula +. "Preciate the help. Bought it for little bar hops and ridin' to places close to the house, and to be honest, since I am only 5'8 and about a buck fifty, I kinda like it. My old shovel can't even think about runnin' and handling as nice as this bike does..This winter I think I'll put the 1250 kit from NHRS on it, and give it a little more power.

I agree, I hate going to the Stealership too, but I get my engine oil and primary oil from HD only.

I run Amsoil in the motor, trans and primary. Very happy with the results.

Here's a link that had some excellent information:

Synthetic Oil

Unfortunately I have not ever got to take a trip that was 5000 miles, thus never needing to change my fluids on a trip; I hope ti change that someday!

If that ever happens though I'd have no issue running HD oil until my next service.

I like amsoil, no issues with it, and I usually order mine direct from amsoil and always order enough for two services so I have it when the need arises.
I use mobil 1 in the motor because easily found and only one that I might need to add to between changes.

What about Redline's 75w90 gear oil with friction modifiers? Heard lots of opinions on that...Seems like quite a few that have sporsters run that brand with good results...After all, someone is making the formula+ for HD..They aren't making it.

I have been meaning to become an AMSOIL dealer but keep puting it off for other things. I think that I need to get that done. I like AMSOIL, it is expensive, but I do not mind spending money on good quality things.

years ago in a hd service manual I read that if one could not find hd oil when on the road to go with a high grade diesel oil so ever since been putting rotella in the bike and 50k later it seems to like it real well

Wow, never heard that one.

Yep,any quality gear oil with the "Limited Slip Differential" additive pack will do fine,just check the bottle and if it says "suitable for wet clutches" you're good to go....

+1

Yup! That's what my manual says cept I can't find diesel oil in 20w/50. It only comes 15w/40 anymore.

I'd rather top it off with a regular straight 50 or 60 oil in a pinch.