Author Topic: hidden nightmares on a layshaft  (Read 620 times)

Online berger

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hidden nightmares on a layshaft
« on: 09.06. 2018 23:43 »
last year I was lucky and received many parts for pre unit boxes plus an rrt2 and feathy frame. well I decided to sort through the boxes when everything was clean and build a replacement box for my betsy because the sleeve gear bushings were worn a tad and dripped oil on sidestand.{note to self an SRM nut and seal would have done} I built a box up using all good stuff and got to the stage where I was ready to swap boxes. I took mine out Friday the 8th and today all I had to do was take the end case off to put my kickstart shaft {altered for japanese kickstart....oh the shame} and clutch arm{ stainless,,posshhe}in the other end case which i'd fitted with a really good speedo drive gear and sealed all the housing in{ don't like oil drips} the gearbox i'd built was turning and changing gear like a good en so on went the end case. everything looking good until I turned the mainshaft and flicked it into gear.the gearbox was clamped in the vice and not put in the bike THANK F**K. the sleeve gear and mainshaft became unbearingly stiff to turn and then freed off. I repeated this several times and decided to remove the end cover. everything went good again. I then put my end case on and the same happened *help*after a cuppa I decided to measure all the worm speedo drive gears thinking I might have a mix of rrt2 and std. but no everything was good,  *dunno* *problem* *conf2*.at this point I thought about removing my sealed speedo drive and changing it for another but something came to my head that said remove the layshaft speedo drive gear that incidently looked like it had never turned with another gear, it looked brand new. so I filed off the pin and drilled a tad to get rid of the preening and tried punching it out only to say to myself this aint going *conf*. so I did the same at the other side and out it came{TAPER PIN STRONG ENOUGH FOR A STEAM PUMP BLOCK good old brit engineering , lets over engineer everything} after heating the layshaft a bit and much effort with a clamp round the gear and much thor hammer blow it came out *smile* I got another gear out of a layshaft by putting a stainless rod down the length of the layshaft and bashing the rod on the back of the vice. those buggers must be pressed in at 10 ton even the fixed pressed on gear came off *woo*. so me thinks I aint bashing that into my layshaft the back of the gearbox will be all over the bench.in the lathe it went and was reduced by means of emery until I was happy I could tap it home.. then to make a taper pin *doubt*ime no lathe turner but was happy with the result finishing off with file and emery and in she went *woo* on went the end cover and YES *clap*everythings good... what I need to know is how the hell can one of those gears get bent enough in the layshaft showing no signs of damage at all. when I put said problem gear in the lathe it was like a dogs hind leg if you looked at the shaft bit with the worm in the chuck.. I turned it round with the shaft in the chuck and by eyesight you couldn't tell because the worm took your eyes  ::hh:: so even tho I thought i'd got the best bits it bit me good style.. tmow ime going to the p..>>no i'm not gearbox is going in THANKYOU FOR LISTENING written with one finger, one question what alien force could have bent such a substantial piece of gear without damage to it......

Offline duTch

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Re: hidden nightmares on a layshaft
« Reply #1 on: 10.06. 2018 00:39 »
 
Quote
.....one question what alien force could have bent such a substantial piece of gear without damage to it.

  *eek*....*The Force*....  may be with you- or not
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline morris

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Re: hidden nightmares on a layshaft
« Reply #2 on: 10.06. 2018 08:52 »
Maybe a rescue from the factory scrap bin? I can imagine some scrap dealer buying factory scrap and then sorting it out for “still usable” parts hoping to get some extra money out of it...?
Regarding taper pins, I never came across one that came out without a fight. They always need some heat and and a well placed big hammer whack. Very effective way to hold a gear on a shaft...
'58 BSA A 10 SA
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Online berger

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Re: hidden nightmares on a layshaft
« Reply #3 on: 10.06. 2018 12:32 »
agreed morris but a taper peg on a gear that's not really got any load and is peened over at both ends is proper brit engineering. and as for it being a scrap bin item I now recall buying a gearbox sprocket from@&@ in the eighties and it was running out of true so bad the chain went from super tight to super slack and they wouldn't change it because I didn't fit it for about a year after purchase so beware what we buy and stick away for another day