Grease is not a good lubricant for garage doors,it tends to collect dirt
quickly and causes accelerated wear to nylon runners which in turn affects
the operation of the door,causing cables to snap prematurely .A recommended
lubricant by most Manufactures is Duck oil,applied on a regular basis it
will keep moisture at bay and keep the door in top condition.Pour into a
spray bottle and keep by the door apply every three months inland more often
by the sea.It will penetrate the torsion spring and keep it in good
condition,that's the one across the top.(these cost around £140.00 to
replace) so the correct lubricant is important.

Alex