If you fitted a new layshaft bush, check the size. It should be reamed to 0.6255-0.6260".

The layshaft measures up at 0.6235", so by my reckoning that's a running clearance of at least 2 thou.

An adjustable H6 hand reamer (19/32" - 21/32") will do the job.

Don't worry too much about getting the size precisely right; just open up the bushing until the layshaft turns freely. Slightly loose is better than too tight.