Gearbox

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
ChrisTheChippy
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Gearbox

Post by ChrisTheChippy »

Hi all
This weekend I finally have time to start sorting out the gearbox problem on the G2 . I have sorted the cause of the problem which was a previous owner trying to fit a new bearing which cracked right through the outside case . I sourced a good condition outside case and looking on the bright side at least I have a new and unused bearing ! The bike was said to be standing for a number of years and looking at the condition of the gearbox which has no wear at all it probably has been rebuilt or very low mileage. I guess whoever decided to replace this bearing just got fed up when things went wrong and chucked it in the back of the garage. It has an inscription underneath the rear number plate which reads dedicated to a friend. If anyone can shed any light on this or recognises this inscription it would be interesting to know some history .
However I digress. Purpose of this post is to ask has anyone used three bond gasket sealant and what are their experiences of it ?
Regards Chris
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Ozmadman
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Re: Gearbox

Post by Ozmadman »

No, I use Wellseal on all my stuff, never use anything else, no thick blobs to fall off and block things up unlike hylomar, just apply with a very small artists brush to both sides leave it t go tacky then assemble
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
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Duncan
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Re: Gearbox

Post by Duncan »

Hi Chris, three bond used to be called Yambond I think, it is good stuff similarly so is Wellseal. I find three bond tends to hold more on disassembly but is better at making up imperfections more than Wellseal, if there is supposed to be a gasket then use a gasket rather than sealant it could impact endfloat.
ChrisTheChippy
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Location: Essex

Re: Gearbox

Post by ChrisTheChippy »

Thanks for your replies and advice . Seems like there is not a lot of difference between these products . They all claim to be fantastic and I guess in a clinical trial situation they do what they claim , unfortunately as we all know things in the workshop ( or outside ) are not sometimes as good as they could be . Think I will try Wellseal see how it goes . I was going to use it without the gasket as I think it might seal more efficiently . Do you think it will affect end float in the gearbox ? I am of the mind that it won't matter a great deal here but as ive never worked on a G2 gearbox before you might know differently from experience . I don't like to do work twice hence this bit of research before I start . Thanks once again for your replies.
Regards Chris
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clanger9
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Re: Gearbox

Post by clanger9 »

You can use gaskets on a G2 box as per the original spec, or you can leave them out and use Wellseal (as most of them seem to end up).
There shouldn't be any issues with the gearbox either way - the design of the centre web and selector fork means gearchanges are unaffected, and these gearboxes run with huge endfloat anyway so it really doesn't matter.

Good luck with the rebuild!
1989 Moto Morini Dart 350
1993 Ducati 750SS
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Janet
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Re: Gearbox

Post by Janet »

ChrisTheChippy wrote: Think I will try Wellseal see how it goes. I was going to use it without the gasket as I think it might seal more efficiently .
If you mean the gasket where the casing joins together, in case you hadn't noticed, there are two and they're not quite the same.
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Ozmadman
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Re: Gearbox

Post by Ozmadman »

I use Wellseal with the gaskets, can't be too sure whether the cases will seal properly without. Nearly 60 years of previous ownership and the related butchery that often goes with it may have left its marks. Be sure when done to fill it with 3 pints of SAE50 engine oil that will take it right up to the bottom of that oval filler/inspection/ clutch arm cover plate, keep it topped right up otherwise you could cause damage to the box as all the gears are in the top half
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
ChrisTheChippy
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Location: Essex

Re: Gearbox

Post by ChrisTheChippy »

Thanks everyone for your replies I will let you know how it goes .
All the best Chris
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Janet
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Re: Gearbox

Post by Janet »

Ozmadman wrote:I use Wellseal with the gaskets, can't be too sure whether the cases will seal properly without.
The gaskets alone sealed on my old heap of a bike. Pity the seal on the shaft behind the gearbox sprocket later started spewing out oil. :(
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Ozmadman
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Re: Gearbox

Post by Ozmadman »

Janet wrote:
Ozmadman wrote:I use Wellseal with the gaskets, can't be too sure whether the cases will seal properly without.
The gaskets alone sealed on my old heap of a bike. Pity the seal on the shaft behind the gearbox sprocket later started spewing out oil. :(
That was good, didn't risk it with mine. I still have a small leak around the gear change shaft though despite trying both types of seals and new o rings. Desn't seem to leak visually but wrapping a cloth round it when left standing for weeks on end results in it getting oil soaked
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
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