Lining up chummy engine with its gearbox!

[Hugh Barnes]

I've always put a chalk mark on the flywheel at TDC having aligned the spline (at the top) to match the position of the gearbox. You can see if the flywheel moves and goes out of alignment, that way. I've also been of the habit of not persevering. If it doesn't go pretty much straight in, I pull everything back and re-align before trying again...