Hey fellas, I've had my primary derby off to inspect the oil level and adjust my clutch before with no major problems. Recently I've noticed the shifting getting a little harder, not much but enough to warrant an inspection. Well, as soon as I took off my lower left bolt (this is a three bolt derby) oil began oozing out. Took off the remaining bolts and cover, freakin' oil just gushed out. I know in my last inspection I topped off the oil level just at the clutch pack with the bike level to the floor. There is obviously a lot more oil in the primary than before. It looks like crank case oil. I'm thinking the main crank seal went **** up and leaked into my primary. I did have to add some crank case oil about a month and a half ago. If it is toast will I have to remove the inner primary to replace it or can it be done with it in place. I think it's a bad crank seal, but I haven't seen this before. Any advice on this subject would be really cool!


Thanks Bobby

 

Its not too big a job and it can be done with the inner primary in place.

 

Inspect the area for a crack as well. The cases are known to crack just outside the bearing area, I think. Do some searches on the forum here. It is rare, but not unheard of, and found by engine oil in the primary.

 

Thanks guys, I'm going to reset my oil levels today and monitor the absence and or presence of said oils after a run, then I'll continue from there. I'll post my findings later today. Thanks alot!!!

 

Alright fellas, I took her out for about an hour and didn't notice any difference in both crank and primary oil levels. The shifting was great like I figured it would be and finding neutral was a breeze. I guess I'll take her for a longer run tomorrow, maybe two to three hours long and then check everylthing out again. I'll update tomorrow.

 

Hey fellas, sorry for the late post, but I haven't been able to ride much lately. I did finally take her out for a good run and just like we thought, the main crank shaft seal is toast. Crank case oil in the primary! Looks like a repair is in order. Thanks for the tips.

 

Are you sure the motor is breathing ok and breather hose is not blocked off? If your getting pressure build up its gotta release somewhere.

 

I haven't checked the breather yet. It would make perfect sense if the hose is clogged. It's located on the lower back side of the case. I'll do that first and get a new filter while I'm at it. I will post my findings as soon as I do. Thanks alot!!!

 

Hey Dr.Hess,

You hit it right on the head!! The seal lip has a small fracture on the bottom side. Besides replacing the case, is there any other fixes for this issue? The original seal didn't have the coating on the outside like my new one so I'm thinking I would help it out with some Hi-temp RTV inside and out? What do you think? I just need this to get me through this riding season and will tear into it in the winter. The leak isn't bad just a pain in the ***.

Thanks Bobby

 

Sorry I was right. I think some people have experimented with different type of sealants and had acceptable results, at least for a while. I think there's one that goes on thin. I think they lay the bike over and let it kinda seep in or something. Do some searching on the sight here. Try a google site specific search, like

bearing crack case site:www.hdforums.com/forum/evo-classic-models

Put that in google and it should just search this forum.