P11 Leaky Primary

elefantrider said:

Is the big lower plug on the Primary cover an oil level check plug like on Commando or a drain plug?

I always considered it was the latter.

Click to expand...

Yeah, old thread and half you guys probably don't own a P11 anymore. That big lower plug is a level check and fill plug.

I solved all the leaks on the primary side except the leak along the bottom of the cover. No more oil coming out of the 3 screws holding the inner cover around the crank, and no oil coming out of the crank seal. Also stopped hypoid from coming into the clutch on the clutch rod with a home made seal. Clutch works better than it ever has. My primary only leaks after ridden, and it's ATF, none of the other fluids are present in the primary. My bike doesn't wet sump anymore either. Ball valve where I can see it. I'd have to be drunk and color blind to leave it closed before kick starting the motor.

Going to try dry mounting the AN primary cover gasket with the green backside today. If it doesn't work, I'll do as Slick did and make one out of 1/16th inch rubber infused cork. Cork works on old cars, so it should work on old bikes. I have made a gasket for the primary cover before. Time consuming, which is why I didn't do it this time. The gasket I made may have worked, but I had all the other classic P11/G15 leaks on the primary side at the time, so don't really know.

I really have a hard time believing old Nortons could ever be leak free if they are ridden. Mine is flawless after wiped down and parked. Ridden, my P11 gently weeps.

If you are intending to run ATF in the primary, be aware that ATF is harsh on most sealants. Permatex #81180 is the only sealant I have found specifically formulated for use with ATF.

Slick

Good to know. I might try that goo next time.

I put a thin line of Permatex Ultra Grey along the bottom mating surface of the inner cover only. The rest is dry mounted, so I can get it apart easier. It's an experiment. I'll know if what I did worked at all in a few hours. My guess is I might get one leak free ride out of it, if the ride is short enough. Cutting a cork gasket is more than likely in my future. I think the cork will hold up better to all the vibration the solid mounted Norton engine has to offer.

Permatex Right Stuff would probably seal it up, but I'd need 2 Jeeps with wenches to get the outer cover off.

I think I have stopped the weep past the transmission shaft at the sliding disks.

My method:
Separate the sliding disks, and invert the inner disk. This puts the felt washer pocket towards the clutch basket.
Inside that pocket, I JB Welded a shaft grease seal (McMaster Carr #5154T61, or 1 1/8" ID x 1 3/8" OD). The seal lip just barely closes over the transmission shaft, when the inner primary cover is fitted (Atlas anyway).

Adjusting the primary chain requires some care: since the seal is pliable, when the gearbox is adjusted, the transmission shaft will push the seal and sliding disks off center. The primary chain should be adjusted over-tight, about 1/4" up/down play, then the gearbox moved 5 flats on the adjuster nut towards the front (loosening the chain). The 5 flat turn of the adjuster bolt should re-center the disk and seal. Vibration will help perfectly center the disk and seal.

The felt washer is compressed by flipping the inner disk over. This also helps prevent oil migration.

On my first run after making this mod, I found a bit of oil weep at the transmission shaft, but this stopped, possibly because the oil weeping was residual from before the mod. or possibly vibration better centered the seal. So far about a 100 miles and no weep.

Slick

2 Jeeps and 2 winches, not wenches. I didn't get back in time to edit my previous comment. Kinda funny. I'm not sure how useful the wenches would be.

I haven't gotten around to starting the P11 to see if what I did on the primary chain cases worked. Too many of the neighbors leaves to rake up while it isn't raining. Darn big leaf maples.

Your mod on the sliding disc setup is interesting. Be great if that does the trick for you.

The primary chain case on my '67 P11 differs quit a bit from the Atlas. No felt washer pocket in the sliding disc arrangement, among other things. What you did gave me some ideas though. Thanks