I'm working on a 1999 fatboy. It has a slow to moderate oil leak clearly coming from between the inner primary and the drive sprocket. I had it to a local shop twice. $400 and it's still leaking although slower... They replaced the inner primary seal, housing o-ring, primary cover gasket, main shaft oil seal. Still leaked without even having any miles on it. Back in the shop. Per the shop, main shaft was fine (mic'd and tested runout) so they installed a 'james' inner primary seal instead of the Harley seal. Well, still leaking, not much, but.....


SO, my question is what else can it be? The machine is squeaky clean under it and it's clear where I see oil from. The inner primary case looked fine to the shop, no cracks, etc. The inner bearing looked good too.


Thoughts?
Cracked case?
Bad seal?
Bad install?
Other seals?
Needs to be driven some? I have about 10 miles on it.
Should I hold the shop responsible? Only 2 mechanics there. Small shop, one is owner and grad of motorcycle mechanic school. I know they did the work....


Thanks,

 

Figure out if it is leaking primary lube or gear lube, drain the primary and re fill with automatic transmission fluid (any type is fine) this will make it obvious. Don`t worry about running the atf, it will not hurt a thing.

If it is leaking primary lube:
Inspect the inner primary cover for damage and cracks. If the cover is ok, replace the inner primary oil seal, the inner primary bearing inner race and the starter jackshaft oil seal.

If it is leaking transmission lube:
Check the primary inner bearing race, it may have walked on the shaft and come in contact with the main drive gear/mainshaft oil seal.

Replace all the seals on the left side of the transmission: the big oil seal, pulley spacer, quad seal, main drive gear to mainshaft oil seal, shifter shaft oil seal.

 

Thanks Dan. I'm pretty sure it's not transmission fluid. The transmission side of the drive sprocket (gear? that drives the final belt) is totally dry. Looking from under side, I can see the leak clearly between the inner primary and the drive sprocket.


The shop that worked on it replaced the seals. I'm not sure if they replaced the inner race again or not. I understand this in not an easy job and a specially puller is needed along with some experience. I do have the manual and tools. I don't buy the typical answer (they all leak) so I expect it to be dry if well maintained. I also don't think the 'just drive it for a while and see what happens' approach will work.


Should I attempt it myself, find another shop or hold the shop I paid accountable?


Thanks for the input.

 

In my opinion you didn`t pay to have them try to fix it, you paid them to fix it. But that`s between you and the shop.

The inner race should always be replaced if the primary is leaking from that seal.

The leak is not going to go away, and any leak is unacceptable.

Removing the race is no big deal, it can be cut off with a dremel tool and cutting wheel (carefully), or pulled off using the proper puller.

Sometimes the race walks up against the main drive gear, and the race must be cut off because there is no room for the puller jaw.

To remove the inner primary cover you must first remove the compensator, the clutch and the primary chain (they will all come off together). You will also remove the starter mount bolts and once the clutch is removed you will remove the starter jackshaft.

You need a locking device to immobilize the compensator and clutch hub while untorquing and torquing their respective retaining nuts, I like using a locking bar. This is all in the service manual.

The compensator nut takes a 1-1/2" socket (short socket is better), and a big breaker bar.

The clutch hub retaining nut takes a 1-3/16" socket. Note: the clutch hub retaining nut is left hand thread.

 

Thanks so much Dan. I believe you are right. The shop owner will go after this again next week. They did replace the inner race when they did the work last time. They did not replace the inner primary main shaft bearing. Would it be possible for the transmission to be leaking while showing bone dry on the transmission side of the drive sprocket? Anyway, they will go after it again since I've already paid for it. I will compensate them for any additional parts and make things fair just because that's how I operate.


I'll follow up when we find something.

 

If the main drive gear/mainshaft seal is leaking, it will leak at the outboard side of the front belt drive sprocket.

The seal is item 4 in the illustration.

http://www.granitestateharleystore.c...55-99A\T18A\BJ

 

Dan and others,
Just thought I would follow up on this. Turns out it was the inner primary seal. The shop replaced all the seals (as Dan suggested above) and zero leaks. It's been a few weeks now and still dry as a bone (although I haven't put many miles on it.) The last two times, it would leak like crazy just sitting there even if it was not used.


Anyway, thanks to all for the help and have a great new year.