Primary Oil?

[scubaman15]

Can anyone tell me why you should use 20/50weight oil in a primary case ?
I know Harley at one time recommended 20/50 but why a heavy oil when a lighter oil 10w/40 syn would lube the bearings and chain and keep the clutch plates closer together for better engagment and float the clutch "dust" off better? The only thing I could think of was that the heavy oil would not sling off the chain as easy but being it rides through the oil that can't be it? Stumped? And what about a open primary how do the bearings get lubed. Just a thought? I have been using 10/40 amsoil motorcycle syn in my softtail primary for three years and the clutch works perfect and I'm not easy on the bike / burnouts ect . What does BDM recommend?

 

[bdmridgeback]

I was told by numerous dealers to not run any synthetic in the Primary.

So I never have. Synthetic everywhere else though.

 

[CCRainman]

Your not suppose to use syn in the primary Scuba. I would go with HD or Revtec primary oil. You only need a qt so it's not like you will shell a lot of $ or save a lot of $ either way.

 

[BBChopper]

I have been using HD primary & trans oil per da book, what weight is it?????

 

[slowrower]

Like BBChopper, I use HD primary oil and Red Line Heavy Duty Shockproof in the transmissions which makes a wold of difference in shifting, finding neutral and noise. Merry XMAS, hope ya'all go what you wanted!

 

[lee]

Like BBChopper, I use HD primary oil and Red Line Heavy Duty Shockproof in the transmissions which makes a wold of difference in shifting, finding neutral and noise. Merry XMAS, hope ya'all go what you wanted!

same here - from what I can tell the only difference between synthetic oil and dino oil is that synthetic oil has smaller molecules and they are each the same size - more and smaller molecules equals more surface area equals greater cooling - I think (can't quite remember) that I am running synthetic in my primary, but don't quote me on that

 

[scubaman15]

Thanks for input but I don't think the questions are answered and to really confuse this area ....think about this ..how the hell does Harley ship its Screamin Eagle bikes with syn oil from factory if the motors are new and yet to broken in ? [/b]

 

[reloaderbmg]

comes down to ,if you buy a screamin eagle bike you "will" get on the throttle to try it out! i work for a car line that ships their cars with mobil one from the get-go!
brake-in with dino oil is a old wifes tail at this point, if you don,t get the rings seated [and that takes pressure above the rings] you will always burn a little oil , because the rings [glazed] only fix pull pistons & rehone cyl. walls.
its the ruff cyl. walls that hold the oil during brake-in!
[thats my rant for the day!!!!!!!! :bang: :angry: :loony:

 

[Lone Dog]

I myself would go with dino juice in the primary, but I don't think that syn would hurt as long as it was specifically designed for bikes.

 

[Black Dawg]

There is nothing wrong with using a syn oil in the primary as long as it has the proper additive (Harley syn oil does, as does any motorcycle or v-twin type oil). Why 20w50, I believe, is that it's just easier to remember one oil for all the sumps versus different ones (I actually read that somewhere in Harley literature).

I run the Redline MTL in the primary. Works great.

 

[yelladog]

I use Klotz syn oil in the primary I've always used syn oil & never had a problem even in my harley's

 

[stiffy]

Can anyone tell me why you should use 20/50weight oil in a primary case ?
I know Harley at one time recommended 20/50 but why a heavy oil when a lighter oil 10w/40 syn would lube the bearings and chain and keep the clutch plates closer together for better engagment and float the clutch "dust" off better? The only thing I could think of was that the heavy oil would not sling off the chain as easy but being it rides through the oil that can't be it? Stumped? And what about a open primary how do the bearings get lubed. Just a thought? I have been using 10/40 amsoil motorcycle syn in my softtail primary for three years and the clutch works perfect and I'm not easy on the bike / burnouts ect . What does BDM recommend?

Hey Scuba,
I'm new to all this. I just changed my starter and was trying to figure out what to put in the primary. Put Amsoil 20/50 Vtwin in the tank. Can I put the same in the primary? Is that what you're running or is it a specific Amsoil primary oil?

 

[07bigdog]

Fatman from Baker told me to run the same oil in the engine and the primary. Use Redline heavy shockproof in the transmission. Now Baker recommends Spectre oil. He also said that you can run synethic.

 

[stiffy]

Thanks 07! I went to the Amsoil website last nite and their chart said you could use their 20-50 Vtwin synthetic in the motor, primary and tranny. That was a little surprising. I put a quart in my primary and took the dog out for a run today. It shifts so much smoother and quieter. I'm sold!

 

[Ridgeback Boy]

I have'nt been on here in a while but last time I was (on the old site) I thought Synthetic was a no no in the primary because it was to slick for the plates?

 

[LDO]

ahhh,
another oil thread!

 

[ZZ CHOP]

Thanks 07! I went to the Amsoil website last nite and their chart said you could use their 20-50 Vtwin synthetic in the motor, primary and tranny. That was a little surprising. I put a quart in my primary and took the dog out for a run today. It shifts so much smoother and quieter. I'm sold!

Stiffy i have a good friend that has a 1988 fxrp with over 250k miles, he replaced the original engine at 150k miles with a new crate engine and it now has over 100k miles, he has never used anything but Amsoil in engine,trans,primary. he told me he has never had a trans problem, i'm sure others have similar results with other oils but i'm sold on the Amsoil..Dave.

 

[scubaman15]

Older post

ahhh,
another oil thread!

A older thread that will never grow old "12-23-07" everyone has a view hear , the fact remains that your primary is nothing but a wet clutch,chain,and bearings.. nothing new hear . Any oil designed to run in a wet clutch should work fine .. I'm Amsoil fan . enough said! Tim "Fibersnake" had a good idea to run ATF and tried it although I have not run this yet, this spring I might try it ...should work great!!! just like your auto tranny ...WET CLUTCH!!! Happy Thanksgiving All

 

[Viszla]

AMSOIL all.

AMSOIL 20w-50 in all three places. Can't go wrong there. Sold at most auto parts shops - but usually "sold out" - so what does that tell you!!

 

[firedog]

Here also! I run the Amsoil 20w-50 in all three. Quieter and shifts easier. But everyone has their preference.