Clutch Pushrod Commando

whassa Barnet clutch please? kind regards

The original Commando clutch push rod is 6mm not 1/4" before you go off on one to RGM.

There are several soloutions to preventing clutch oiling. you can get a seal to go on the end of the sleeve gear, you can grind a small groove in the push rod and fit a small O ring. (amal carb air screw or throttle stop screw o ring comes to mind) pack the hole through the main shaft with grease or dare I say it, silicon bath sealant.

I guess that 6mm gives a satisfactory clearance through what was probably a 1/4" hole. The NOC service notes suggested cutting the rod in two, hardening the two new ends and fitting a 1/4" ball bearing between the two halves to remove the issue of the rod bowing under pressure. I did this mod about 35years ago but to be honest, the chance of the rod bowing under the pressure of a cable operated lever is probably nil. Also, any oil has to find its way up into the RH end of the main shaft then migrate through the hole and end up in the centre of the clutch. I recently did the groove and rubber ring thing in one end of each of my two bits of push rod. The clutch action is now notchy. So me being a smart arse has not payed off. Probably only needed one rubber o ring. If you have 1/4" silver steel make one and see if it works. (harden and temper the ends) the hole through the main shaft is rough.

Previously john_hall1 wrote:

Hi,

Bought a Clutch push Rod from a known supplier consisting of three letters and up in the Northern wastelands, only to find that it has a diameter, having been checked by Micrometer, is Metric and six mm rather than the 1/4 inch Imperial measurement originally fitted in the glorious earlier days of the Empire!

SNIP

The commando, featherbed twins and garden gate twins back to 1949 used 6mm push rods.

Around 1988 I saw an article where someone in England made a clutch rod seal. I could not buy one anywhere and only heard someone in australia made some. I could never find them...

I designed and made my own, based on 6mm rods and had some guys that wanted one also...

Well to date I have sold just under 6000 for commando. Norvil sell my seals, while RGM refused to talk to me about them??? I got the same nonresponse from NOC parts scheme?

Singles by mail to england is stupid expensive. I just sent 5 @ club/shop price to a private sale to England the other day.

IMO the cut shaft and ball bearing or o-ring groove is pathetic.

You can read about them on my website atlanticgreen.com, but in reality if I never sell another one of my seals it's not a big deal to me.

Hi David, I bought one of your clutch rod seals many years ago, maybe around 2000. It's still fitted and works fine, here in the UK. You might or might not recall that to begin with I had an issue, in that the clutch end of my mainshaft is countersunk into the pushrod hole, meaning that the o-ring couldn't make a seal â at the time we decided this was an oddity, and I got around it by making a shim out of a beer can to go between the end of the mainshaft and the o-ring, obviously with a hole for the pushrod to pass through, thereby holding the o-ring, perhaps even compressing it somewhat, into its seat in the cap that screws onto the end of the shaft. Anyway, the thing is it works, and I'm happy to vouch for your seal. My clutch used to get very sticky and slippy from time to time, but it hasn't since I fitted this seal, although I've replaced the o-ring once or twice â o-ring 04.0079 for the gearbox ratchet spindle does the job for me.

Why no-one other than N*rv*l wants to stock it in the UK is beyond me. I'd previously tried the o-ring-on-the-pushrod idea, but, while the inside of my mainshaft doesn't seem rough â the o-ring's still there undamaged, when I last looked this summer â it didn't stop gear oil getting onto my clutch. I know it's gear oil, because I run Norman White's dry belt drive.

Hi Colin

The story of the extra deep chamfer on the main shaft does ring a bell. This seems to be quite rare, but I've only had maybe 3 like that in all these years.

The imperial sized oring...dash 010 (-010) oring is correct as you state for the gearbox shaft seal 04-0079 and my Commando CRS and Atlas CRS though the final design is for the 6mm rod.

I have not previously heard of a seal on the end of the sleeve gear (per David Evans) that would do any thing for the clutch plate oiling since it is outside of the clutch on the back side of the drum? Maybe he can explain.

Gearbox venting/ pressure?A persistent rumor I felt need investigating.Read my report below.Attachments
gearboxpressure-rtf

My mistake, the clutch seal was fitted on the clutch end of the main shaft not the sleeve gear. I bought one from Norvil years ago and when I went to check it after about 10,000 miles it had been eaten by the inner face of the diaphram center.

Previously john_hall1 wrote:

Interesting stuff!

Pre-49 was it a quarter inch bar fabrication then?

Many Thanks

John H

I own 2 garden gate twins, so I have first hand experience back to the model 7 era, continuing with several featherbeds and many commandos. I can't speak to pre model 7 1949 push rods. After you find out what size rod is in early bikes let us know...though I will not be designing seals for them.

Previously David Comeau wrote:

Hi Colin

The story of the extra deep chamfer on the main shaft does ring a bell. This seems to be quite rare, but I've only had maybe 3 like that in all these years.

I wonder how this chamfer/countersink arose then, as it seems to be so rare â another bit of Norton trivia to ponder!

I have four of Dave Comeau's clutch push rod seals that are surplus to requirements, and I'll sell them on for a lot less than Norvil wants.

Tel: 01963 240010

Mob: 0790 353 2620

Email: peter_hatfield at yahoo.co.uk

I have sold two already! Therefore, I have only two left - price is £20 + £1 P&P.

Only one left now.

Attachments
ClutchRodSeal.JPG