A gearHead is born

So....My gearbox outer cover was leaking, I ordered some Allen bolts. Then while my buddy was riding with me (I was on my '67 TR6C, he was on my '74 Commando) he pulled over & had the bike stuck in 4th gear. I figure, get it open, find busted pawl spring, replace & finish with those handy dandy stainless allens. Only thing I noticed while limping it home was that the gear lever seemed to do nothing but the indicator was way forward of the gear position numbers on the case. I wasn't riding it, so I didn't know what the circumstances were at the time it stuck there. While getting it apart in the order indicated in the manual, it felt like it shifted or changed a position when I applied counterClockwise pressure on the bolt holding the gear indicator.. Well dang.. Too late, I'm takin' it apart anyway. Spring is good. All is pretty. Can't find a problem. Back together, seems to shift into all gears while sitting there not running. I'm not going to run it 'til I get some new gear oil in there.

Does this sound familiar?

Also, what's up with the drain plug? If that's the level you fill it to, how is it a drain plug. I opened my drain & nothing came out. When I took the cover off, it all spilled out.

Also, I noticed my kick start shaft has "play", in & out movement. Maybe 1/16 to 1/8 travel. Is that normal?

I did discover someone before me had installed the MK3 breather vent as well as drilling the tiny hole in the inspection cover.

Gearbox drain plug is just to fool the innocent just like the primary case level plug.
If you fill to those levels you will have a mess as it seeks its natural level. I look down the inspection hole and fill so oil or ATF just covers the cog top seen deep down in the inside cover. Buy two pawl springs and remember where it is.

ATF, automatic transmission fluid?

Yes, old news to put ATF in forks or primary or gearbox. No real reason but to see color of leaks or it running redline rpms in low gears a low time. Personally I now like power steering fluid in my Roadholders, boy I love writing that as sounds so looney tooney but works a treat for me.

platinumsmith said:

Also, what's up with the drain plug? If that's the level you fill it to, how is it a drain plug. I opened my drain & nothing came out. When I took the cover off, it all spilled out.

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There's two plugs on the gearbox, sounds like you removed just the level plug. The drain plug will drain all the gear lube.

Thank you 2wheels! I missed that.

Given that I found no apparent issues, is is possible that my buddy just tried too hard pushing down on my gear shifter & drove the selector too far forward & it hung there?

Could be. After I had my shift pawl assembly fall off from the 2 bolts being loose, I re-installed it and it would stick when shifting down. I took it apart again and found that just loosening the 2 assembly screws and jiggling the assembly around, it stopped sticking. You might want to make sure the tit for the centering spring is not jamming on the back plate like mine did.

Dave
69S

FWIW, there should not be 1/8 inch of travel in the kick start shaft. End play there should be something closer to .005 of an inch. I am not an expert as to what might be causing this but that movement is excessive.

There is a DVD available on gearbox servicing by Mick Hemmings. Might be worth spending the 45 bucks.

Russ

There's two plugs on the gearbox, sounds like you removed just the level plug. The drain plug will drain all the gear lube.

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Inspection of my gearbox 74-850 indicates that the drain plug appears to be there but the level plug seems to be missing, that is no hole for this plug. Interesting thing is that the oil level in the gear box appears to be just below the drain plug - this I suspect is not good.
Has anyone seen a gear box without either the drain or the level plug. Should I just fill it to 0.9 pints per the manual?

I can tell ya one thing for sure, regardless if an upper plug installed or not, filling to that level is same as over filling the primary to its over flow plug, a big mess till it reaches its innate fluid capacity, which will end up after too few miles, just barely covering the top of the cog you can see with a flash light deep down inside inner case/cover via the fill hole.

In my stupid learning curve I tried to get this plug out, ugh and finally did with some galling, for above, then about never got the plug to stop lopsening or leaking till I glued it in permanent. But that was on the first gb shell Peel and I ruined, so know better now than disturb them any more. Its another one of Norton jokes on innocents.

I must admit, I could not find a drainPlug on my '74 850. Got down there & looked everywhere.

JimR said:

Inspection of my gearbox 74-850 indicates that the drain plug appears to be there but the level plug seems to be missing, that is no hole for this plug. Interesting thing is that the oil level in the gear box appears to be just below the drain plug - this I suspect is not good.
Has anyone seen a gear box without either the drain or the level plug. Should I just fill it to 0.9 pints per the manual?

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I think you could be mistaking the level plug for the drain plug? After all, how can the oil level be "just below the drain plug"?

platinumsmith said:

I must admit, I could not find a drainPlug on my '74 850. Got down there & looked everywhere.

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This is the drain plug (note that the standard drain plug hexagon is smaller than the one in the photo)

hobot said:

I can tell ya one thing for sure, regardless if an upper plug installed or not, filling to that level is same as over filling the primary to its over flow plug, a big mess till it reaches its innate fluid capacity, which will end up after too few miles, just barely covering the top of the cog you can see with a flash light deep down inside inner case/cover via the fill hole.

In my stupid learning curve I tried to get this plug out, ugh and finally did with some galling, for above, then about never got the plug to stop lopsening or leaking till I glued it in permanent. But that was on the first gb shell Peel and I ruined, so know better now than disturb them any more. Its another one of Norton jokes on innocents.

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If I cant see deep down inside at the top cog. how would the level look in relation to the kick start shaft. I have been running 90w oil about half way up the shaft.
Im getting clutch slip and have a leak comming from the kickstart and gear change shafts?
Im looking at running a 50/50 mix of ATF and tranny stop slip (thick as honey)in the gearbox so if any goes through the clutch shaft my clutch wont slip.
also running atf in the primary.

good or bad move???

also on the top of the gear box I have a letter L stamped beside serial number ? what does this mean?

cheers
Paul

Thanks L.A.B
Embarrassing that I've never changed the gear box oil, but never looked there. The drawings naturally aren't able to show the exact location. But now I know. I'm glad I asked was getting afraid that I'd been running without oil and, of course, that didn't make sense since the gear box was working fine.

pingu-nz said:

also on the top of the gear box I have a letter L stamped beside serial number ? what does this mean?

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The stamped letters were factory code used to identify a particular production change relating to the actual engine or gearbox. As far as I am aware, there is no list available that identifies what the letters mean.

Well, I do have a drain Plug! (but it ain't as clean as that one)