1st gear slipping into neutral???

What could be the problem every time i go a certain speed in first it slips into neutral its highly annoying and today I took her out at light i couldnt get it in neutral from first please help??? :x Vince



1974 Norton Commando 850
1975 GT750M
1988 Ducati Paso LTD

Current build - 1979 GS1000S Wes cooley replica

Mine did that, it was the kickstart shaft needed shimming. Can you pull your kickstart in and out at the gearbox?

If N is hard to find, I suspect a too tight primary chain, but that doesn't explain the slipping out of 1st. Is your clutch set up properly?

Dave
69S

Also first gear bush could be worn and/or fractured. It is the most thin and fragile bush on the whole bike. Drain the gearbox oil and inspect the oil for fine brass particulates.

i just bought a 74 commando. mine is hard to get into first sometimes. and it does seem to be from the kick start shaft moving in and out. whats the fix to this?

first gear bush could be worn and/or fractured. It is the most thin and fragile bush on the whole bike. Drain the gearbox oil and inspect the oil for fine brass particulates.

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2+ above. The diagnostic key is only certain speeds which is a mis-observation as it should be only at almost neutral loads on drive train like going slow coasting on closed or barely opened throttle. If say you are in a bit of a lean turning in traffic or parking lot timidly and expecting a bit of drag to keep bike aimed and slowing it can select N for you to release bike for too fast for the turn radius or let rear slip right out from under, when hitting a bit of a bump or gap in surface like a shallow pot hole.

Most owners that use 1st gear now and then and all owners who spend a bit of time in 1st gear should have 1st gear bushes on hand along with other regular consumables like spark plugs and oil and filers and tires. Too bad by time 1st bush is noticed its wobbled to death its neighbors too. Its not a simple switch out even though simple to access, you have to fit each bush to its shaft and cog, ugh.

Commandos are the coolest bike kits out there to put right to use.

Rathead said:

i just bought a 74 commando. mine is hard to get into first sometimes. and it does seem to be from the kick start shaft moving in and out. whats the fix to this?

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Shim the kickstart shaft to .005'' - .010'' end play. Instructions can be found on the old britts site: http://www.oldbritts.com/ob_start.html Go to "build or restore your own commando" then click on "assembling the commando gearbox" the shimming info is about 1/3 of the way down the article.

Matt

Rathead, trouble going into 1st is usually the clutch. Gearbox oil contaminated plates, notched clutch center,loose clutch nut,adjustments etc. Popping out of gear is usually a kickershaft shimming job or new bush replacement.

i found best not to use any gaskets in the gearbox which also seems to take up the kicker shaft slack too. There is no reason to use gaskets except tradition. Goop needed of course if not the kind that glues stuff together.

hobot said:

i found best not to use any gaskets in the gearbox which also seems to take up the kicker shaft slack too. There is no reason to use gaskets except tradition. Goop needed of course if not the kind that glues stuff together.

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That is to say that if "play" is the issue. If play is not the issue and you do not use a gasket, things could bind, especially if you shim. I know this first hand.

My first gear would slip out under load.

The force and torque on the detent and spring on the cam plate is like no other gear. I changed my detent spring and the issue disappeared. Detents themselves can round off a bit. A good conical shape should be observed on the end of the detent.
Many causes, many solutions.

A mal-adjusted or gunked up clutch will also keep the gears from slipping all the way into their positions, I suppose. It would certainly make neutral harder to find.

I did not come up with the no gasket solution by my own innovation but at advice of vendors and decades long builders before me after too many tear ups recoveries I ran out of them and it was explained to me gaskets have no function in AMC shell to space or even seal anything. I had no issues of kicker engagement or slick shifting just missing teeth, torn up bushes and bent shafts and wallowed out bearing bores. Oh sure I'd finished off a racket pawl but that was unrelated to anything else wrong in tranny, just various owners and me having at it.

I crashed twice in same day d/t 1s bush going away in the un-serviced tanny that came with Ms Peel. first by coasting down extra slow and cautious ~18 mph on steep tight hi way to hang way way back from traffic after I'd flown up the plateau face at least a gear shift faster than any modern capable of. but rear crossed ~ 1" low gap in pavement chunk, to slide out from under leaving me to run a few yd to stand in middle of road watching Peel slide dozens of yd down the steep into a rail and then second by extra cautious coasting into my drive way turn ~12 mph that rear crossed ~2" deep leaf filled rut that released mild rear drag and skipped rear out just enough to dump bike on a 2 ft high grader berm to protect the bike fall on its $500 new painted tank by breaking my innominate/pelvic bone and fractured a genetically fused L5/Si facet joint. I was pleased I did not scratch paint and 7 months later that my life long bending strain had re-grown a new joint so now can touch floor and squat in Norton worship no problemo at age 60 and decreasing.

I know a bit about chain tension extremes and extreme rpm in lower gears now and don't use gaskets anywhere in Norton no more but the head and even that may be eliminated next time in both Trixie and Peel. Hylomar is my one goop sealer.

Do not confuse slipping out of gear dangers with merely annoying not slipping into gear issues - they have different causes and solutions and risks.

+1 on the Hylomar blue, that's some good goo.

I have no gasket between the gearbox shell and the inner cover, just Hylomar Blue. It worked so good on the crankcase so I thought I would use it there too. I found things a little tight without the gasket at the outer cover but that's not to say that it isn't a bad idea.

Thanks to all that replied. The kicker does move a good amount I m gonna take a look when I have a minute. Btw what did you use to shim it????????? Make your own or purchased them??? Vince

tigman88 said:

Thanks to all that replied. The kicker does move a good amount I m gonna take a look when I have a minute. Btw what did you use to shim it????????? Make your own or purchased them??? Vince

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Rear ISO shims.
Go here and scroll half way down for detailed info.
http://www.oldbritts.com/gearbox_a.html

Order up new detent spring while you re at it. Cheap insurance. 04-0442 $2.44 usd