Author Topic: Help ! - Gearbox jammed!!  (Read 1074 times)

Offline brackenfel

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  • Adrian - Bristol UK
Help ! - Gearbox jammed!!
« on: 27.07. 2010 19:51 »
Dear All,
I cannot believe how much aggro a BSA gearbox can cause.. I had no problem with a Burman or an AJS one but this thing defies belief..
If it wasn't so expensive I'd be using a 4lb hammer and a wrecking bar at this stage, I'm that fed up with it....

All seemed to be going well. box reassembly was straightforward, everything nice and clean, repaired / replaced where necessary.. So I just thought I'd check selection before putting the outer case on.....
got as far as 4th & stuck, wouldn't change down. With hefty screwdriver persuaded it down one gear & that was it!!

So I had no choice but to take it apart. Damaged a new gasket & got oil all over the Wellseal on the faces. Resigned myself to making a list to order including new gasket..
The mainshaft came out with the inner casing & the other 2 gears came out no problem.. The layshaft is a different matter as the selector is not in neutral, neither will it go there without excessive violence being offered..

My question:-
If I remove the selector plunger mech will this help? the selector plate is supported by another bolt & lockwasher - does this have to come off too??

Surely there must be a way?
All help (and counselling!)  appreciated..

Thanks

Adrian
1961 A10 650 Golden Flash - Blue
1954 BSA B33
Velocette Viper
Laverda 750 SF1
Kawasaki W650
Buell XB9S
Ariel 350NH & Matchless G3LS in bits...

Online chaterlea25

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Re: Help ! - Gearbox jammed!!
« Reply #1 on: 27.07. 2010 20:05 »
Hi Adrian,
Unusual problem?????
Heres how to remove the layshaft!!
remove the grubscrew on the sprocket end of the selector rod and pull out the selector rod
You can then pop the engagement peg out from the camplate and withdraw the layshaft

Hard to check now but were/are the selector forks over both sliding gear lips ??

HTH
John o R
1961 Super Rocket
1963 RGS (ongoing)

Offline brackenfel

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Re: Help ! - Gearbox jammed!!
« Reply #2 on: 27.07. 2010 22:14 »
Hi John,
Selector rod already out but as the thing is still in gear (turning sprocket turns layshaft) the engagement arm is wedged under the sleeve gear & won't quite lift out.
The forks were over both sliding gear lips - the problem seems to be the peg getting jammed in the selector grooves... This is why I wonder if removing the camplate plunger will help as I might be able to move the plate better then....

Adrian
1961 A10 650 Golden Flash - Blue
1954 BSA B33
Velocette Viper
Laverda 750 SF1
Kawasaki W650
Buell XB9S
Ariel 350NH & Matchless G3LS in bits...

Online chaterlea25

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Re: Help ! - Gearbox jammed!!
« Reply #3 on: 27.07. 2010 23:33 »
HI again Adrian,
It wont hurt to loosen or remove the plunger mech!!
I cant see why the peg would jam in the camplate??
Unless its bent??

HTH
John O R
1961 Super Rocket
1963 RGS (ongoing)

Offline brackenfel

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  • Adrian - Bristol UK
Re: Help ! - Gearbox jammed!!
« Reply #4 on: 29.07. 2010 07:22 »
Thanks John...

Eventually managed to "waggle" the gear out with the plunger in 2nd.. Waiting for new gasket & other bits from C&D so I can then have another go! Everything looks straight & these are the original selector parts but I do have some spare forks so I'll compare them just in case
Thanks for your help..

Adrian
1961 A10 650 Golden Flash - Blue
1954 BSA B33
Velocette Viper
Laverda 750 SF1
Kawasaki W650
Buell XB9S
Ariel 350NH & Matchless G3LS in bits...