A10 gear box gaskets or gasket maker?

[mario medeiros]

What is used more to reassemble your gear box dry gaskets or with some gasket maker or no gasket and just use gasket maker?

I think the one i use is Permatex moto seal much like Yamabond.

Thanks

[muskrat]

G'day Mario.
I make most of my gaskets, mostly 0.4 & 0.8mm.
For sealant I use Permatex #3 aviation. If carefull the gaskets can be re-used.
Cheers

[Slymo]

I use Flexoid 0.4 or 0.8mm assembled dry and retightened after a couple of days. Don't leak and can be re used a couple of times at least.

[KiwiGF]

What is used more to reassemble your gear box dry gaskets or with some gasket maker or no gasket and just use gasket maker?

I think the one i use is Permatex moto seal much like Yamabond.

Thanks

From memory the gearbox gaskets are unusually thin, maybe 010” if you use thicker material (or none) it may affect end floats etc.

[Greybeard]

Just a quick note. I found on my Plunger bike, after the box was overhauled, I had to remove the inner cover gasket before the gearbox would work properly.

[bsa-bill]

I had to remove the inner cover gasket before the gearbox would work properly.

Funny old world GB, I had to put an extra gasket in to get mine going 

[Swarfcut]

 Good mating faces, paper gaskets and Hylomar work for me. In the old days it was Red Hermetite.  Both are non setting types. Paper gaskets and Silicone work for bruised casings, but as always, not too much. Gasket thickness can be critical in some cases, as in earlier posts.

 Swarfy.

[Black Sheep]

A smear of gease on the gasket works for me. Also means gasket is reusable. My contribution to saving the planet.

[BSA_54A10]

The thickness of the inner gasket controls the end float in layshaft and moved the mainshaft with respect the the 4th gear dogs.
The thickness of the front gasket controls the clearance for the kick start & moves it with respect to the kick start pinion.
Because of all of the variations on the thicknesses of things like the flange on top hat bushes you some times need to alter the thickness of the gaskets .
I have just done a box for the M20 and had to put a 1mm front gasket in there to prevent the kick start fouling and also jambing on the ratchet

So button the box up full tight and verify that the kick start will return properly and all gears select properly before you even think about gaskets
I use some shim washers between the inner & main castings and again between the inner & outer to determine what ( if any ) thickness of gaskets is required.
T was always gong to make up some gasket sets from shim stock so I could do this properly but another one of those "roundtuit" jobs for when I find the box that I stored the spare time in.

[JohnnyM]

Hello,  I have acquired two A7/A10 gearboxes.  One is solid…not turning and the other appears okay.  However looking at these boxes there appears to be no gaskets in any of the joints.  Did BSA produce gearboxes without gaskets? 

[muskrat]

G'day Johnny 
Short answer NO. We find the plunger box's need a very thin or no gasket (or silicon) between the box and inner cover ((depending on wear) SA boxes aren't as fussy)). A thickish gasket between inner and outer. Are they plunger or S?A boxes?
I see you have a B (we'll forgive you) and the box's are very similar or same.
Cheers

[Swarfcut]

 That inner gasket also determines the relationship between the camplate and gear selector mechanism. Plunger box uses a claw, so depth of engagement is critical. S/A box has a toothed quadrant and spring loaded pawl design, so reckon this accounts for more leeway with thickness of gasket on S/A boxes. Thicker inner gasket will allow more layshaft endfloat, and also move the clutch nearer to the primary case, but if you're running this close already, you got a problem!

 For a seized unknown box, a heat gun will help to free off some parts. With the selector rod removed, the whole ensemble will come out with the exception of the camplate and final drive sleeve. Camplate can then be eased off its pivot. If the selector rod is rusted to the selector arms, then it is a tough call. In all cases I'd start with that pesky grub screw, and replace it as the last job, to avoid unintended damage to the main case.

 Swarfy.

[JohnnyM]

Thank you both for these very knowledgeable responses!  Musky, these are both plunger boxes I believe.  I looked at both closely and there are know visible signs of gaskets at all on both.  They don’t look to have been molested in many’s a year. I have overhauled many B boxes but this is my first (graduation) into A boxes.
Apology for only attaining a B status 😊.  I was searching for some indication to my dilemma when I stumbled over your forum!  Or should I say knowledge base!!! 

Swarfy, the box that isn’t turning/moving. I took the outer casing off yesterday and found that whatever oil had been used in the past has actually changed state into a hard caramel and coated/stuck everything.  I fancy when I get into the gears then they’ll also all be stuck together!  It smells horrible…maybe an old diff oil that has just broken down!   
Thanks, Johnny.

[Swarfcut]

   Jonno....You may be in luck as regards the state of the innards, preserved in old lubricant rather than rusty water. Filling the box with turps* (cheap enough from the likes of the DIY sheds) and leaving mainshaft down for a week or so with a catcher for the drips could be a way forward rather than the usual domestic oven or barby to free it off. The A series gearbox is very simple compared to B rigid and plunger boxes and there is plenty on the Forum for you to explore.

 Swarfy.

 *In the mists of time, paraffin (kerosene) was what we used. If you happen to have an oil fired boiler, the odd pint of heating oil won't be missed. That's kero.  I reckon WD40 is turps based.......

[muskrat]

G'day Johnny.
Pay close attention to the claw that engages the cam plate and the cam plate pivot. The claw pivot must be free without play. That's where most problems arise with gear selection.
Even with new claw my box would only work with a 10 thou gasket between box and inner cover. Any thicker the claw would miss.
The outer cover gasket as thin as you can go without binding the kick/gear levers.
Another check is the kickstart pinion and quadrant are the same type (flat or pointy teeth).
Cheers