Clutch rod seal

I was doing some routine maintenance today to prepare my September trip, and I thought I might share my solution to stop gear oil migrating to the clutch:
First a shortened std rod, then a 6mm bearing ball and then a +/- 3 cm rod with an O-ring.
The idea is the the O-ring stays put, and the rod slides trough it.
I make them from an old 6.8 mm twist drill shaft.
O-ring is from Amal set screws.
Length is cut so that the felt washer just fills the gap between main shaft and clutch adjuster .
Works perfect.

ludwig said:

I was doing some routine maintenance today to prepare my September trip, and I thought I might share my solution to stop gear oil migrating to the clutch:
First a shortened std rod, then a 6mm bearing ball and then a +/- 3 cm rod with an O-ring.
The idea is the the O-ring stays put, and the rod slides trough it.
I make them from an old 6.8 mm twist drill shaft.
O-ring is from Amal set screws.
Length is cut so that the felt washer just fills the gap between main shaft and clutch adjuster .
Works perfect.

Click to expand...

Ludwig, excellent engineering! But I wonder, are there issues with the simpler approach from Dynodave?

Ed

Just curious, never experienced any problem with gearbox oil creeping to the clutch. How to tell if it happens? How common is it? How to know if it's not the oil in the primary that contaminates the clutch?

Looks interesting. Always fun to try something different.

I'm not using a DynoDave clutch rod seal either. My approach for my 5 plate Atlas type clutch is much simpler than DynoDave's setup. Sort of a condom arrangement using a vacuum port cap with the tip punch cut a little smaller than the clutch rod diameter. Clutch rod goes through the hole in the end of the cap, and the vacuum cap fits tight over the end of the main shaft the clutch rod goes through. (It's not a soft rubber vacuum cap. I'm not sure what it is made of, but the oil and heat in the primary don't bother it. I do expect it will get harder and possibly shrink some in that environment after about 10 years.) I didn't take any pics of what I did, and I don't expect it will last forever or stop a little oil from migrating out of the transmission entirely, but I don't put many miles on my Norton, so it's good enough to last until I can't kick it over anymore.

I've been over filling my transmission forever, which I think probably contributes to trans fluid coming out of the main shaft around the clutch rod. Spec in the manual I have, and have not been paying attention to, is considerably less. I'll be trying the spec from now on. .9 of a US Pint. Also trying some 75-140 Lucas synthetic gear oil for grins. ATF in the primary with bottom of the primary chain just skimming on the oil. So far so good.

Don't over fill the gear box and there be no problem, I put the right amount in it that the workshop manual says to use, I also put grease on the clutch rod and in 45 years I have never had gearbox oil find its way into the primary or clutch, I found out years ago that using the level tube in the GB over fills the GB.

Ashley

ludwig said:

I was doing some routine maintenance today to prepare my September trip, and I thought I might share my solution to stop gear oil migrating to the clutch:
First a shortened std rod, then a 6mm bearing ball and then a +/- 3 cm rod with an O-ring.
The idea is the the O-ring stays put, and the rod slides trough it.
I make them from an old 6.8 mm twist drill shaft.
O-ring is from Amal set screws.
Length is cut so that the felt washer just fills the gap between main shaft and clutch adjuster .
Works perfect.

Click to expand...

Probably in the late 60s I used to do that machining mod to the full length pushrod but never used a felt washer. It did work okay but the O rings wore out after a few 1000 miles. Later I fitted a lip seal to the end of the main shaft and never touched it again. Perhaps a Vition O ring would increase the life? Nice job, though you might need to harden the ends.

Mike40M said:

Just curious, never experienced any problem with gearbox oil creeping to the clutch. How to tell if it happens? How common is it? How to know if it's not the oil in the primary that contaminates the clutch?

Click to expand...

if you're using motor oil in the primary it probably doesn't matter. with ATF the gearbox oil will darken it, though it may be hard to tell after some miles. I'm using one of dave's seals and even with that I see oil around the pushrod (very obvious now with a dry primary).

I am curious, what is the purpose of the felt washer?

cash said:

Probably in the late 60s I used to do that machining mod to the full length pushrod but never used a felt washer. It did work okay but the O rings wore out after a few 1000 miles. Later I fitted a lip seal to the end of the main shaft and never touched it again. Perhaps a Vition O ring would increase the life? Nice job, though you might need to harden the ends.

Click to expand...

I believe the bearing ball helps to reduce wear.
O-ring lasts for many years.
Hardness is no problem.
It is not like I made this yesterday, but more like 25 years ago.

Stephen: the felt ring fills the gap between main shaft and adjuster bolt.
It holds some grease to keep the tip lubed.
The adjuster bolt is drilled for the same reason.

Very nice indeed.
Dave

We have Norvins and Tritons, etc. Since there is so much that is custom (in a good way) on Ludwig's Commando, we should cristen it a Norwig...

APRRSV said:

Ludwig, excellent engineering! But I wonder, are there issues with the simpler approach from Dynodave?

Ed

Click to expand...

There is a "special" nut you can buy called the "Dave Comeau" seal. I just put mine on but you must remove the clutch diaphram to install it.

Dynodave IS Dave Comeau. Or is that vice versa?