I've managed to remove 5th gear from my IB5 gearbox and now I want to put it back on but I'm really struggling.

I've put the gear inside the oven at Gas Mark 9 for 30mins then tried to put it on but I can't get it on enough to put the snap-ring back on. It's about 5mm from being fully on.

Anyone got any tips or do I simply need to get the gear even hotter?

Many Thanks
Ste