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Collection, Preservation and Display of Old Lawn Mowers

Removal of Driving Spigot from Atco Crankshaft

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Hi, I am restoring a 1950's Atco 17" mower. I have it all broken down except for the part pictured which appears to be screwed onto the end of the crankshaft. It does not want to move! Any hints/tips much appreciated before I end up breaking it!

Thanks

Martin

 

 

 

Forums

wristpin Thu, 21/04/2016

The first thing to be aware of is that it's a built up crank with the shaft ends and crank pin pressed into the crank webs/ balance weights and then aligned in a fixture with dial gauges. If you get too rough with it you stand the risk of twisting it out of alignment.

This is what I would do but be aware that there is some risk attached and I'm quite prepared to be told that there's a better way!

I would reassemble the engine and lock the piston by poking a quantity of stout cord down the plug hole until most of the space is taken up and the piston cant pass top dead centre. You can then grip the dog with a set of stillsons and unscrew it . As the rotation of the engine is trying to tighten it , it should be a conventional right hand thread.

If it resists undoing, and this may sound a bit brutal , lay the dog on an anvil , substantial bit of iron or a good strong malleable iron vice  so that it is parallel with it and hit it with a heavy hammer rotating it through 90 degrees so as to hit at 12,3,6 and 9 o'clock. This will shock the threads and may loosen them. Then try the stillsons again.