How to fix stiff Lockwood window winders?

[valandi]

I have a number of hopper windows throughout our house and some of the Stegbar winders have become quite stiff to operate. How can I free up the action? Thankyou

[valandi]

Above is the back of the Stegbar Winder. There is a thin metal backing plate secured in 4 places (two shown. They are posts that have been rolled over after fitting the plate.

So I drilled them out to open the unit.

[valandi]

[valandi]

Above, the internal workings of the unit. The cog to the right is driven by a worm feed. I cleaned everything with kerosine, but the unit remains quite stiff.

I am going to give it a bit of  spray with WD40 with Lithium and put it back on the window. I'll have to use the pressure of the attachment to the window to keep thee backing plate in place.

 My feeling at this stage is that there is no real way of reducing the residual stiffness. It is better than before but not great.

[MitchellMc]

I'd be trying to work some lithium grease into the worm gear and then using it sparingly on the chain @valandi. You'll get a longer lifespan out of that than from the spray products.

Mitchell