In the Shop
As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.
Unsophisticated and Unashamed
Aug 29, 2008
One of the things I respect in other mechanics is the ability to fix things with class and style. Anybody can take a big hammer and bludgeon machinery into submission; I respect anyone who can use expertise and a few special tools to make repairs with some degree of mechanical elegance.
But there are times when brutality is beneficial and actually efficient. Removing bearings frozen to shafts is a good example. The elegant way to make the repair is to use a bearing splitter, a gear puller, or to remove the entire shaft then use a hydraulic press to take things apart. But I make my money by doing jobs as quickly and efficiently as possible, so elegance often goes out the window if brutality gets the job done more quickly.
I'll usually make one pass with an air hammer and pry bar at a stubborn bearing just to see if buzzing the end of the shaft while prying against the bearing will slide things apart. Wonderful, if it works, but normally my next step is grab an acetylene torch and start melting metal.
It ain't pretty, and it's not a valid solution if you're working on transmissions, differentials or other precision components in gearboxes. But if you're dealing with bearings on shafts in combines, augers, or other non-gearbox situations--fire is your friend. With a torch and a pair of tinted goggles/glasses, most bearings are history 10 minutes after the torch pops to life. Veteran bearing-burners can slice lock collars, bearings, sprockets and gears off shafts with little more than discoloration to the shaft. With practice on some old, used shafts and bearings, it becomes relatively easy to slice through bearing races until you see the darker, cooler metal of the shaft, and thus avoid major damage to the shaft. Even if the torch's flame nicks the shaft, as long as most of the shaft's surface is intact so the new bearing and lock collar have a firm seat, a little work with a file and emery cloth will have things ready for reassembly in minutes.
Now for the disclaimers: Use caution when using a torch to remove bearings. Keep fire extinguishers or garden hoses handy. It's best to wet down adjacent areas in advance to minimize the chance of fire. Be wary of bursts of flame when the torch's flame briefly ignites grease inside the bearing. Be prepared for glowing-hot ball bearings that fall from partially disassembled bearings, roll down your arm and land (briefly, very briefly) in the waistband of your pants or in your lap, if you're sitting. Trust me--it happens.
In other words, use common sense. If you can't use common sense, then at least learn from your mistakes.
In the end, it's not a pretty, elegant or sophisticated way to make repairs. But then I'm not a pretty, elegant or sophisticated guy, so it works well for me.