I was under the impression that only a S1 casing could be used in a S1 due to the tie bar assembly.

My understanding is you can fit an S1 box to an S2 but not the other way round.

The myth surrounding the diesel box being tougher has been around for ages. It IS a myth though and the box is no tougher and has no LSD. The only thing in it's favour is it's cheap.

Bernie at CTS is the man who sorted my gearbox out and since fitting his box (my 13th) I've had no problems

www.gearboxman.co.uk