I’m currently servicing 2 FW four-speed hubs for a friend.
One of them is in very nice condition and needs nothing more than a good clean and lubrication. I opened the gear and examined the internals as my friend requested and stripped it down as far as the planet cage. There was no need to go any further as this gear is in very nice condition. I sprayed it with WD40 to clean it – WD40 is excellent for cleaning steel components – then reassembled it and filled it with good quality lawn-mower oil. The hub is now ticking away perfectly.
The second hub is running roughly. I removed the internal and instantly saw the problem. It has a layer of sticky goo over all of the components. This has been caused by using the wrong oil. Many household oils turn to a sticky varnish as they age. The only remedy here is a complete strip down and careful cleaning of all of the individual parts.
The hub has been stripped and is in the process of being rebuilt. I intend to finish this job on Monday.
PLEASE, when you lubricate your Sturmey Archer hub use 30 grade lawnmower oil. Nothing else!