Hi, i need some help figuring this primary leak out. I just bought a used forty eight. It has some rash on the lower primary. They changed the Derby cover to a Harley skull chrome assuming the old one had rash. The problem is I noticed it was a minor oil leak coming from the Derby cover similar to sweating oil. I go to replace the o ring. It look like the previous owner used some gasket sealer on the Derby cover. Anyway I clean everything out the new seal on and tighten it hand tight with a 27 torx screw driver because A lot of people say not to torque to 84-108in lb because you will strip the threads. The Derby cover drips oil within minutes. The Derby cover doesn't look warp. The outer primary cover seem pretty straight the bottom but it is possible the bottom might have a slight curve but extremely hard to tell and without looking at another sportster primary I can't tell if that is normal. Also I would think tighten the cover would cause the gasket to compress a bit and seal a little imperfections. I don't want to replace the outer primary and to find out it still leak or create new one by installing Another primary. What do you guys suggest? I'm not having problems keeping the gasket in the groove. I used some grease to keep it in place. Yet again I cannot verify if the primary has a slight imperfections, it looks normal to my eyes. I'm trying to get this bike ready for Daytona and in NY I'm freezing working on this bike in my garage.

 

What are you running for fluid? ATF?
If so maybe try something a little heaver...BUT I would take a real close look at that sealing surface of your cover.
Thats all I got.

 

When I had my sporty I remember that gasket/o-ring didn't want to stay in place. I put a few dabs of gasket sealer on the o-ring and held it in place until it would stay there and let it sit for a while, hope this helps....

 

Check and see if your oring is still soft,then put it back in the groove and take a straight edge and see if it sticks out far enough to crush together when you tighten it down.
You might need a bigger oring,or if possible try another cover.

 

How are your washers? I had the same problem, until I put in the sealing washers.

 

You might have pinched it. I pinched mine once and left a trail of oil all over the roads.

Go in and clean it all up with degreaser, reset (or replace) the gasket, and then bolt it down in the cross-wise star pattern to ensure an even seal.

the dealer gaskets are great (seriously). Cometic gasket are greatererer.

fun times

 

If it didn't leak before...
a) Damaged Derby cover.
b) Large O-ring.
c) Clutch Cable O-Ring.
d) Torx mounting bolt washer/ seals.
e) Trans fluid incorrect type.

My vote:
Most likely pinched large O-ring...about $2.50 at a dealer.
Less likely, the new Derby cover is faulty...need to exchange.

Good luck.

 

Do they sell bigger washer?. When I went to the dealership they sold me the square o-ring. Then I tried tighten it the star pattern. I don't think I pinched it but I wouldn't know or able to see it. I had Softail and the Derby cover never gave me this many issues. The gasket stick out the groove a bit and looks good. The Derby cover look straight. I used a glass to see if it rocked at all. If I can try to upload photos I will.

 

Here the picture of the Derby cover. I need to upload the primary cover next.

 

Are you sure the leak is from the Derby Cover gasket and not the O-ring for the clutch cable?