Thanks for your input, I gave up before damaging it. I took the worm covers off and put a small amount of grease on the worms each end. I also put a tiny amount of oil on the motor bearings, it runs nicely now.
I will now leave it alone!
Am away for a couple of days, next up is the detailing pack. Should only take a month or two!
The “clicking” was more like a soft sound similar to a playing card on the spokes of a bike wheel, but very much quieter,,so “clicking” was the wrong word I used.