Layshaft: Balls or rollers

I cut my teeth Mr. Hudson's old tapes. It was the TS crank shaft I remember him hand belt sanding slight facets here and there off the roundness till the ball bearing slipped on/off w/o effort. Made me cock my head on seeing it. I could only rationalize as a tenderfoot, that maybe heat swell made it to spin on the balls not the shaft.

Anywho back on point. What do I see wrong with theses picture? What would be wrong with simply correcting it by a closer mating in the middle?

You could certainly reduce the end play by eliminating the gasket or removing metal from the surface of the main case- but a shim is easier. And a greased gasket there makes it easy to do a roadside kicker pawl replacement when needed. Jim

LOL! Greasy gritty gasket is more convenient for road side emergency pawl repairs -ugh. Anyway thanks for the back door validity, but come on now what's easier than just forgetting to install an item or two compared. Got a gift form my 93 yr old aunt Alice today for Peel parts, like gearbox renewal items and a lower ratio 1st set, so get to practice what I preach, now I know to check lay shaft play.

Shimming the gearbox to prevent first gear problems has been a normal shop practice since the AMC box came to be used on large motors. Long before anyone ever thought of installing a roller bearing on the layshaft. This information was courtesy of Brian Slark many years ago. And yes .010 or .020 means a lot. I have certainly cured many gearboxes that popped out of first with nothing but a few shims. Jim[/quote]

Thank you Jim for that insight and answer to a lingering query in the back of my mind! Sounds like a properly fitted ball should be checked and shimmed for end float accordingly. Theres so much emphasis on locking the outer race of a bearing to the housing, what about the inner race??
As our Ol'mate and Norton guru Mick on his DVD states ( pointed out by Les in another bearing thread) layshaft should be a slip in fit!? Yes I know Mick has probably forgotten more about Nortons than I'll ever know and he could rebuild a box with his eyes closed.
BUT, IMHO, I cant agree with that and after rebuilding various gearboxes out of trucks, tractors, motorcycle (Burman, Harley) and grain Harvesters shafts etc etc Ive learned that the under high loads where HP converted to torque bearings can and will turn, not where they're supposed to, eg; shaft and housing! what a fuggan mess!Some bearings for these high load situations come with cam lockers or grub screws to reduce the buggery factor. Our Norton trans obviously dont so must rely (IMHO remember, because of experience) on an interference fit to the shaft. The only movement possible should be within the races, thats what the bearing is for!
Just yesterday I rebuilt my trans hoping it will cope with what a warm 920 cc will dish out. YES I used the FAG roller as its load rating is twice that of a ball! Was happy with its fittment to the shaft as the inner race was a slight interference fit eased on with the press. Shimming took all of 10 minutes (including enlarging shims, .010 & .005 for .005 end play) and have to agree with Nortonspeed, wondering whats all the fuss about? Took hobots advice and didnt use the gasket, Locktite 515. I could see the genuine gasket more fiddly than the shims.
At the end of the day you're the one who has got to be happy knowing you've done the best to your ability.
Its taken me longer to type this than the shimming exercise!
FWIW
foxy

Yeah well I normally carry a pawl and some tools when I go on a rode trip. I have replaced mine one time on the road in the last 30 years. I have replaced pawls on other peoples bikes several times in motel parking lots and at rallies. Doing my bike with the gasket firmly glued to the case on one side and a light coating of grease on the cover was a 20 minute job. I just laid the bike over to the left and did it.

I cant say that about other peoples bikes when I had to scrape what was left of a stuck gasket off and find something to replace it with. Jim

One of the best informative threads. Thanks all.

Dave
69S

I cant say that about other peoples bikes when I had to scrape what was left of a stuck gasket off and find something to replace it with. Jim

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hehe next time out bet ya will only look for easy to find sealer. Carrying spare hard parts is admirable for sure but gaskets, ugh. Only gasket left in Peel is on her head but that may go too.

Going by this subject's data banks, I'm sold on a roller in mean Peel but bet ya can't tell the difference in bikes not meant for abuse. Likely something else tears up to go in again, before the roller beats the mileage of a ball and by then likely replace whether it needs to or now... Coin toss surprise me on my Trixie unless a distinct price difference.

All interesting comments on the layshaft transmission side bearing. However, I am still struggling with all the bearing conversation, yet the other end is just a bushing. All i can figure is that the main shaft has a big load what with being driven by the motor, and driving the rear wheel so needs a ball bearing each end to keep it spinning smoothly, square and supported, but the other end of the layshaft just needs the kicker side bushings to hold it steady. The right side of the layshaft rides in the kicker shaft bush, and the kicker shaft rides in inner cover bush. So since the layshaft is transferring power from the main shaft back to the main shaft, for the layshaft the trans side bearing and the right side bushings are sufficient to keep the shaft straight, spinning evenly and allowing for the kickstart to fit and operate. I suppose if there is a question here, is there any comment on why either end is supported so differently?

I just wish I could remember all the things on here, Jim I kinda feel that if you were to do a repair and workshop manual it would really be a hot seller. :wink:

Hortons Norton said:

I just wish I could remember all the things on here, Jim I kinda feel that if you were to do a repair and workshop manual it would really be a hot seller. :wink:

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I have. it is here for free.

Actually the bronze bushing on the kicker end of the layshaft has a higher load capacity than a ball or roller bearing. However it will not live with miss-alignment or poor lube.

One reason I prefer a roller to a ball bearing is if it wears out and gets rough and you ignore the noise and keep riding , it will destroy the cage just like a ball bearing. But due to the close spacing of the rollers it is unlikely to lock up suddenly like a ball bearing does if the cage goes away. The balls in a ball bearing must be spaced farther apart to allow for assembly so if the cage comes apart the balls will all go to one side and lock the bearing.

Either bearing is adequate however as long as you use a HD ball bearing. Jim

comnoz said:

I have. it is here for free.

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True very true

One reason I prefer a roller to a ball bearing is if it wears out and gets rough and you ignore the noise and keep riding , it will destroy the cage just like a ball bearing. But due to the close spacing of the rollers it is unlikely to lock up suddenly like a ball bearing does if the cage goes away. The balls in a ball bearing must be spaced farther apart to allow for assembly so if the cage comes apart the balls will all go to one side and lock the bearing.

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Tie breaker and game point Jim, throw in the ole towel and wrap it up. Risk of lock up vs just noise annoyed no brainer.




On a side note, Wes showed me how a frugal hillbilly checks for bearing re-use, dry turning and turning and turning and turning slowly till all the worse defects line up at once to be felt for an instant, then ditto some more to make sure, then some more intervals of fine function till feeling the glitch again, and again. Then oiled to feel if disappears the glitch or not to decide on how spend thrift to be or not.

Used bearings are like food left in the refrigerator. If in doubt, throw it out.

If in doubt, throw it out.

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A relative sliding scale concept in our perfect world but even shade tree machinists know one glitch felt = burnt toast.
I expect to go though a few sets of bushes before bearings shot, so how should one decide its time, just because the box is apart for some other reason? Subject line is settled > good rollers are safer than best balls, so what's left but a new subject line on frugal bearing evaluation? I may of mis led ya on the crudeness of Wes's examination, it was more like a safe cracker in meditative focus, mesmerizing the first time I watched, then took me a while to mimic it and feel the subtle hint of brindling. Just spinning smooth with a flick ain't good enough. The bicycle addicts are real bearing maniacs as Wes once was.

Thrown hundreds of OK bearings in the bin in the name of preventive maintenance. I'm aware of the catastrophe lurking that a new bearing can prevent!

Why would you need anything but grease on the gearbox gaskets? There is no pressure as the geabox is open to atmosphere. Good sealing is all about good sealing surfaces, not the gaskets. As for shimming, I have never bothered and never had a problem after a lot of gearbox overhauls. Having publicly said that I am bound to get nothing but problems from this point forward....;-)

OK, so here's what I've gotten from my original question: Replace the old bearing with a good new ball or roller bearing; shimming may or may not be necessary; gaskets and sealants are optional. Is there any more I should know?

Paint seal from rust the outer case guts that lie above oil level. Top it off per manual and/or drain plug and ride long enough spell or 3 that it seeks its natural level you can then calibrate a dip stick or sighting in at correct level on future 'top' offs and many changes. Grease the clutch rod to help stifle leaks and corrosion. The knuckle/fist cam gizmo gets set - cogs engaged as close to edge as possible yet not quite preventing the cover from closing. Its worth while to do a break in on ATF or cheap lube then flush after a few 1oo miles then 'top' off with your long term lube. Might oil groove the sleeve bushes as they go dry in lower gear use. Keep two kicker pawls, pawl shifter flipper spring and 1st gear bushes on hand, one set in use the others on standby. Open slot in kick lever and remove a few splines on either side and maybe run a real grade 8 bolt through with a nut on the end. Search up the kicker sealing options DIY to send off to vendor machinist. Can grind kicker peg stops to get the thing out of your calf on factory pegs. Might also touch up polish the cam slots and follower.

This thread has been timely for me. As you know I have just taken my gearbox apart to replace the layshaft bearing.
After much reading and reasoning, I have decided to go with the roller bearing replacement. My question now is as I prepare to order some shims,
where exactly do the shims go? And should I order front or rear isolastic shims. I've never seen either.
THanks,
JD

jaydee75 said:

where exactly do the shims go?

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http://www.oldbritts.com/gearbox_a.html

jaydee75 said:

And should I order front or rear isolastic shims.

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Rear

See text: http://www.oldbritts.com/gearbox_a.html