Hi angboy,
The adjustment blade rod gets a lot of saw dust and after a little while it gets tight to turn as you described.
The best way to resolve that problem is to use a air compressor and blow all the sawdust on the rod and wheel, making sure all the contact parts on that rod get clean, then using dry graphite dust (found in any hardware store and is cheap) pour all over the rod and contact parts of it, use a small brush if you find difficult to pours with the bottle long nozzle they come with!
This is very much part of the machine's general maintenance and should be done every so often, depending on the amount of use you have on the bandsaw!:biggrin:
Cheers
George