i run 20 -50 ams oil in both holes

 

I run Amsoil 20w-50 in both holes. I found that the whole bike runs smoother this way. 5000 miles between fluid change is also nice.

 

Local shop put amsoil motor oil in mine
didnt know it til the end and i threw a stink
about it.

 

20-50 is what Harley recommends for your bike. I've used 20-50 Amsoil in mine for 10 years with no problems.

 

I've run 20-50 in mine since it was new... got over 30k on it and never had a problem with oil...

I run dino in the motor and the syn in the other hole...



Charlie D.

 

I run amsoil 20/50 with no problems. 15,000 miles and doesnt burn a drop and no more metal on the tranny plug...

 

Same here. The tranny is a LOT more noisey with the 20-50 in it. And, to me, noise in a tranny is not a good thing.

clunk clang

Has anyone tried the Amsoil Gear Lube or Severe Gear lube? They make a 75W-90.

 

Use whatever you want, but I don't run a "motor oil" in the manual transmissions of my 4-wheel vehicles, and I won't use it in the manual transmissions on my Harley's.

Also, don't become 'brainwashed' my marketing hype when it comes to the high dollar Motorcycle Specific Oils. Many lower cost fluids have been shown to work just as well, or better.

In the shared primary/transmission on Sportsters any API GL-5 rated fluid will work fine, just be sure to use something that doesn't contain a high level of moly which 'might' have an impact on the wet clutch pack.

You can run the $10.00+ synthetic fluids in your engine, but once again it's not necessary. UOA's show that Mobil 1 15W50 shows results very close to that of Mobil 1 20W50 V-Twin, but it only cost $4.25 a quart around here when purchased in bulk 5 gallon containers.

Also, it might be worth mentioning that motor oils and gear lube is measured differently when it comes to viscosity.

Many think a 75W90 Gear Lube is much "thicker" than a 20W50 motor oil... This is not true.

Anyway, run whatever you want, spend whatever you want, but your engine and transmission could probably care less as long as the fluids are changed at reasonable intervals.

Below is what myself and many I know run in our Sportsters. A Harley dealership mechanic friend of mine has been running the below combination in his 2004 Sportster for over 90,000 miles now, and he (along with the rest of us) have had ZERO issues or problems.






And just for information purposes, here is a chart that shows the actual viscosity (thickness) of motor oils and gear lubes. As you can see, a 75W90 gear lube has about the same viscosity as a 20W50 motor oil.

 

I use Olive oil.

 

Whichever oil you use in the engine, it should be rated CF-4, CG-4, CI-4 or rated for diesel engines.

This type of oil withstands higher temperature than gasoline engine oils before thermal viscosity breakdown.

See your owners manual.

BTW, the oils marketed as V-TWIN or motorcycle oil are not diesel rated!