Sportster Primary.....

[Bushshaker]

Hello all,

I've been a lurker for awhile, my first post here. I first would like to say I love this site. Lots of very knowledgeable folks here. I never really put much thought into oils, I was just taught to change them often. All that changed in 2012. I bought a nearly new 500 miles old Forty-Eight. A friend bought it new and quickly became scared of bikes. The bike has always had a slappy/whiney primary. Chain is adjusted correctly, never any shavings on magnetic drain bolt. Now the bike has 5k miles and I've probably tried every oil/gear oil in primary I could to ease the clunky whiney slap sounding primary on a sweet strong running bike.

I'm not trying to push any manufacture or knock another but, Red-line 80w Shockproof has helped quiet things down and I swear the bike seems to have less drag. I have no data to prove this! Bike fast shifts better than ever and finding neutral is a breeze. I've put maybe 200 hundred miles on it, everything still seems to be improving. I still have a very slight whine and clunking. The clunking I've had on several Sportster's. Thinking this is a HD trait.

Now to ask, how can this be? I would think a thicker oil would quiet things more, I live in South Georgia, will this thin oil still perform in 100 degrees with 100% humidity? I'm so confused but in a good way! Any thoughts would be appreciated.

Respectfully, The Bushshaker

 

[dave123]

Many things going on in gear oil not just that it's thick or thin. Redline just happens to be one of the best You can get.

 

[endeavor to persevere]

Red Line does not recommend shock proof oil in the Sportster primary as it may cause the clutch disc to stick. And The 80 shockproof is not as thick as the 50 weight oil recommended by Harley. Gear oil and motor oil viscosity are not measured the same.

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

 

[Bushshaker]

I'm running the 80W gear oil that the Red Line website recommends for Sportster's. For info follow link: http://www.redlineoil.com/product.aspx?pid=112&pcid=13

I was reluctant to try it at first until I read up on it. It does seem logical that it is to thin but, it seems to be performing very well. I've tried a popular 75W90 but, I did not like the way bike was shifting. I have a quart of Red Line 75W90 GL-5 on the way but, I may not change it. The bike is running very well. Feel wise and sound, I'm really impressed with the 80w Shockproof but, I am worried about the summers heat coming. I also ordered 20w60 for the engine. That is how impressed I was with my first taste of a Red Line product.

From looking at Red Lines website, plus as much confusion that is on the Internet about what to run in a Sporty primary. I was even confused what to run. That is how I found this site thankfully. I've been riding them for almost 30 years and changing my own oil. Never really put much thought into it till this bike. If Red Line would put that their GL-5 is yellow metal safe. They would sell tons of it.

Respectfully, Bushshaker

 

[Robenstein]

Gear oils viscosities are not measured the same as engine oil viscositties. So an 80w is in the same ballpark as a straight 50 engine oil.

Somewhere out there on the net there is a conversion table that allows you to compare the two.

 

[benjy]

Redline makes quality products with great Tech + Customer service! you can actually talk to a real person for answers, rare these days

 

[Kory]

I run AMSoil 20W-50 V-twin in both holes. Would be interested to try a redline product.

I doubt I'd notice much difference but it might be worth a try just to say I did it.

The clunk will be in a sporty transmission no matter what oil is in there. You are right it's just the way they are.

 

[SJohnson]

Originally Posted By: Robenstein
Gear oils viscosities are not measured the same as engine oil viscositties. So an 80w is in the same ballpark as a straight 50 engine oil.

Somewhere out there on the net there is a conversion table that allows you to compare the two.


Here's one.

http://www.doolittleoil.com/faq/viscosity-sae-iso-or-agma

 

[Doog]

I always used HD Syn3 20w50 in my Sportster...no issues. Have an experienced Harley mechanic ride the bike and listen to the primary. It could be a worn sprocket/chain/ tensioner or other parts. I have seen a bad rotor stator make that noise as well. A bad trans bearing can do the same.