Ferguson 3V22 belt change

[tiv48]

take a look at the idler tyre may be hard .its so long since i have done one of these that i cant remember if the take up spool is driven by a slipping clutch belt driven from the capistain or just friction driven from the idler.try covering the casset bulb and push down the small micro switch the mech should then run with no tape inserted you should then see what is suposed to turn what.
a photo of the top pref with the cage removed and the underside would help jog the memory
rob t