If I do an oil change with Mobil 1 20w50 Vtwin oil, can the same oil be used in the transmission? The Screamin Eagle synthetic oil I have been using can go in both places.

 

It can but the tranny will like gear oil better. You might want to try the Mobil 1 75/90 or 75/140 gear oil instead.

 

Yes but a lot of folks on here recommend using gear oil in the transmission. I'm going with the 20w50 Vtwin in all three for simplicity sake. Yeah, I'm lazy but if it doesn't work well, it's not that hard to change. BTW, Kragen has the Mobil 1 20w50 vtwin on sale for $7.99 a quart right now (at least in Cali).

There's a whole section on here for oil related topics: https://www.hdforums.com/forum/oil-a...0&daysprune=-1. Check out the polls if you want to see what others are using. Seems like #1 is Amsoil, #2 Mobil 1 vtwin, #3 Syn3. Although just cause it's popular doesn't mean it's right.

 

I saw it here in Ohio for $7.99 at Oreilly's autoparts.

 

Yup. Oreilly's=Kragen=Checkers=Schucks. They're all the same company.

 

That's where it belongs.

 

I use the 75/90 in my trans, world of difference on the shifting. So much better than the engine oil.

 

That's what I did. It does make a great difference.

 

Kinda what I was thinkin.

 

Yes, it can be used in both the engine and trans/primary sumps on your Sportster. Some guys use 75w90 gear oil in the trans/primary and some use the 20w50 in there. But you should always use the 20w50 in the engine.

I just used 20w50 in both on my Sportster.