I've heard great things about this oil, but has anyone used it in a Sportster transmission?

 

I always used HD syn3 because it has no moly in it that could cause your clutch to slip. But it is good oil for the engine. The oils with no moly are:

HD syn3 20w50
Mobil1Vtwin 20w50
Redline MT90 75w90 Manual trans lube.

That said there are probably a million sportsters using oil with moly so who knows. I sold my Sporty but if I still had it I would try the redline MT90. You can find it at www.racerpartswholesale.com

 

So you're saying the Havoline contains moly?

 

Most of the automotive oils contain different anti-wear additives that are not designed for a wet clutch application. Since Havoline is an automotive oil it probably has some of these. Many people use them in thier clutch with no ill side effects but I won't because of that reason alone. Since you are only saving a few bucks over HD syn3 and Syn3 is a better oil than Havoline my thoughts are why take the chance? Plus you can run Syn3 5000 miles and I wouldn't run Havoline over 3000. Do the math and with the cost of the extra oil filter you use changing at 3000it's about the same price. 30,000 miles= 6 syn3 oil changes & 6 filters or 10 Havoline oil changes & 10 filters. Just saying.