so i have the stock derby cover on my 09 rk and just bought the hd skull and chains derby cover to replace it. when i removed it the other day i noticed that the stock cover has a groove for the orange oring and the new one is all open with no groove. does that new derby cover take the newer flat disc gasket or will the orange orin work on that?

 

The flat disc gasket is the old style which fits aftermarket and old style HD derby covers. The O ring will not work.

 

thanks for the quick response , sounds like i need a flat disc gasket then

 

If the derby cover doesn't have a groove cut into it close to the edge, it takes a flat gasket.

 

Yes you need the flat gasket.

 

HD quit using the orange o ring and came out with the paper ones as oem. Too bad you dont have the grooved one as they will last the life of the bike.

 

Ahhhh Guys(!)....

My S/E Road Glide came with the O Ring gasket and a derby cover with NO O Ring groove. Only my primary cover is grooved.

Op, try it with the O Ring gasket. You have nothing but 5 minutes to lose.

Doesn't work, go buy a flat gasket.

I'm betting it will work just fine.

 

Grooved primary cover. Now that's a new one.

 

If there is no groove in the derby cover OR the primary, then the o-ring will NOT work.

I have not seen/heard of the grooved primary cover.

 

This is correct