[CARB]

I found that if there was a slight binding then running the gear box dry for a few minuets took off the high spots and then it was nice a free running.

Another trick is to build the gear box and leave the screws loose, run the gear box and tighten up the screws as it is turning, don't over tighten they just need nipping up no way near tight remember it is a plastic gear box and not off a Jcb digger.

It is also worth paying special attention to the bearings wash them in acetone (nail polish remover is a cheap easy way to buy it) then oil up (soak) with Triflow PTFE lubricant and allow to drain on a claean piece of kitchen roll.

I check that the outter shields are not damaged with a magnifying glass especially the right hand lay shaft slipper shaft bearing is good as this little one gets a lot of load and being sort of external gets dirt in it.