Morris Minor Owners Club

Phil was right ! I had put the wrong laygear in. I'd had three laygear sets which looked identical to me but I managed to pick the wrong one. Either of the others would have been fine. There are no part numbers on them, so you have to count the number of teeth which in the case of a 1098 Minor are 13,19,24,28. Mine had one or two teeth less on larger gears so there was no chance of it fitting. Looking at the roller bearings I believe I've done them some damage so with all the work involved I'd better get another pair. At least I'm fairly confident it will all fit together now.

Aha, sounds like you fitted an MG Midget/Sprite layshaft, which has 13, 19, 23 and 26 teeth and also a differing helix angle compared to the Minor 1098cc one.