Gearbox gasket paper

[Paul_Linden]

How thin is the gasket paper in Burman gearboxes?

The box I am working on is a GB30 from a Colt, and there wasn't enough left of the old gasket to measure it.

The parts manual shows two gaskets but Draganfly doesn't stock them. I have some .020" gasket paper but this seems a bit on the thick side from what I recall of previous gearbox rebuilds (20 years ago!) and I don't want to get the layshaft endfloat wrong.

Thanks in advance for any info.

[pete.collings]

I'm not sure about a Colt gearbox, but I have not used any paper gaskets on the heavyweight Ariel GB gearboxes for a long time. I just clean the mating faces (inner and outer covers) to make sure there is only bare metal with no obvious high spots, and apply a THIN layer of silicone gasket to one face. Allow this to cure, preferably overnight, and then smear the surface with oil and assemble carefully.
This has the advantage of sealing any damage by previous (less careful!) owners, and the covers can be removed and the seal reused a few times if care is taken on removal.
I don't think there is much problem with setting the endfloat with a used gearbox (unless it is excessive), but if you have fitted new layshaft bushes these may need easing if the shaft is tight on trial assembly of the gearbox.

[nevhunter]

I think that originally they would have had a paper gasket. the sealants we have today work ok if everything is clean but You can still apply them tp the paper, ( or at least one side). I just use thick brown paper,
End float if excessive in a burman box will sometimes cause trouble, particularly the layshaft and the selector assembly, which affect how much the "gears" engage and whether they will stay in gear. Nev