Freeing Seized Parts
THE BASICS
Be patient if you are having problems removing a seized part. A little time spent thinking about a problem now is better than making time later to fix something broken in the heat of the moment.
Most seized parts can be freed easily without any special tools.
Removing rust and other deposits from exposed threads by wire brushing makes it easier to remove nuts.
Apply lubricating or penetrating oil to help free seized parts. It is amazing how well this works.
For really stubborn parts, immersion in diesel oil can often work wonders, especially if you leave it for a few days.
Sometimes it may be necessary to drill out a thread or cut off a bolt head. This is a last resort and you will need to take care to work on something that can be replaced relatively easily later on. Remember, nuts and bolts are easier to replace than other parts of the mower.
SPECIAL TOOLS
Impact screwdrivers can be a useful tool. These are designed to turn the nut or bolt a fraction of a turn suddenly and with additional force. They should be used carefully but can often free seemingly seized parts.
Gear pullers can be helpful for removing sprockets or gear wheels that are stuck on their shaft. Ideally the pulling force should be applied as close to the central shaft as possible to avoid placing undue stress on the outer extremeties of components. There is a potential problem with spoked or open sprockets found on many early hand mowers. It is very easy to apply too much force with these tools and break the sprocket so proceed with care. Try not to apply force to the outer rim of these.
Drifts and tapered cold chisels can be used to apply force behind a sprocket or gear wheel, again as close to the shaft as possible, to "push" it off the shaft.
USING HEAT
Applying heat to the seized components often helps to free them. This is a specialised task, particularly for larger or heavier items, and the best advice is to ask someone who knows what they are doing to help.
Many local blacksmiths, metalworkers or welders will have the correct tools and will be happy to help for a small fee.
Small parts can often be freed simply by placing them in the base of an open fire or bonfire and leaving them for an hour or two to heat up. Make sure the parts have cooled down before you handle them afterwards.
Do not force cooling by immersing parts in water as this is potentially dangerous and may cause damage.