How many use 20W50 vtwin in there primary? Or is the gear oil a better idea 75w90?

 

I'm using it in both holes. Switch from over priced Royal Purple Max Cycle. Seems like my bike runs much cooler now.

 

no gear oil in the primary ! v-twin 20-50 is fine.

 

Gear oil is great. V Twin oil or any other motorcycle oil you get to pay more because it has a picture of a motorcycle on it.

 

I feel like this has been the topic most brought back up.
I like to keep this bookmarked: https://www.hdforums.com/forum/sport...l#post14946336

Personally I use gear oil and just regular non-vtwin synthetic in the motor. As stated, it is cheaper and i cannot possibly imagine how it is different. Motorcycles ran just fine before special v-twin has been around and it rubs me wrong it goes in both holes.

 

Did you think I was being sexual about that. LMFAO!!! That's been said for many years when it comes to Sportster's.

 

I saw my chance and i took it. You cant even blame me.

But in all seriousness I feel there is a reason Harley gives you two places for oil to go rather than the old, everything shares oil strategy. That was before my time but I really only read about it. Is it going to hurt anything, absolutely not. But if its more expensive then why bother. Just my 2 cents.

 

Just thought you were one of those political correctness people. Good to know that you're not.

 

https://www.hdforums.com/forum/sport...-answered.html


Here is Red Lines recommendation.

Thank you for contacting Red Line Oil, in the shared Sportster primary/transmission the 75W90 is recommended, a product that has been used extensively and performs well.

The 75W90 is the product we have have used for a number of years with very good results in Sportster/Buell transmissions, matching the viscosity and type fluid called for.
The 80W Motorcycle Gear Oil is a lower viscosity than called for, the ShockProof gear oils can due to their unique characteristics could cause sticking of the Harley clutches.
The 75W90 would be preferred and recommended over 80W Motorcycle Gear Oil in these applications.

There can be issues with some GL-5 gear oils in certain applications. Some can be corrosive to brass, bronze or copper, not an issue with our GL-5 gear oils, they don’t cause corrosion, pitting or metal removal. In a synchro equipped transmission the friction modifiers contained in many gear oils can make them too slippery, though not the case in a motorcycle transmission with dog rings.


So if you want the right viscosity and dont want to worry about it damaging anything, go with Redline http://www.redlineoil.com/product.aspx?pid=133&pcid=4

 

+1 to Redline in the Primary (as he says do not use the Shockproof one though as it will mess with your clutch plates)