We're rebuilding my brothers gearbox which was damaged when it was crashed into.
The only thing wrong with it (fingers crossed) is a cracked bell housing and dented backplate.
We have sourced both, but were wondering if we need to use sealant or gaskets on either, I cant find anybody selling gaskets or sealant for the g-box(?)
Hopefully someone can clarify
Cheers

There's a paper gasket on each of the output shaft housings ( also called a tri-ax gasket), which usually don't survive disassembly.
http://www.ecas2cvparts.co.uk/gearbox-o ... -1293.html

For bell housing and rear cover to main casing joints, a good quality gasket goo is essential.
My preference is for this one.
http://www.wellseal.co.uk/

I hope that you're going to peen/stake the selector ring and replace the rear bearing on the mainshaft whilst the gearbox is on the bench.
I haven't had to deal with an 'unwound' gearbox for years, then had two in the last couple of months, so it looks as though there are still people working on 2CVs who cba to do a bit of preventative maintenance when putting shiny cars together...

ken

I don't know about shiny cars, but I don't do any maintenance.