Posted by David Sherman on Saturday, May 12, 2007 at 19:10:13 :
In Reply to: Pound them out with a hammer and drift. posted by chriscase on Saturday, May 12, 2007 at 19:00:17 :
I tend to agree. I don't have the money to replace everything that it would maybe be nice to replace as a matched set all the time. If the bearing cups look good, I'd leave them in. "Good" to me means perhaps some discoloration or dullness, but no chips, no rust, no cracks, and definitely nothing you can catch your finger in. Even tiny rust spots or chips tend to get pummeled into serious cracks (or cracked rollers) pretty quickly under load. There's also a flaking phenomenon, sort of a network of fine surface cracks, that probably comes from metal fatigue, that's cause for replacment. In my experience, I'd say I probably replace about half as many cups as cones.
For a big bearing, a Timken cone can easily run $60, and the cup $40, so especially if you have a lot of them to do, if the cups are still smooth, you can save real money and lots of time by leaving the old ones in.
I tend to like a real puller or driving tool rather than the "alternate pounding" method, since it's too easy to get it cocked a little bit and bung it all up by pounding. Depending on the particular installation, large wrench sockets, pieces of pipe, and sections of old shafting can be used as installation/removal tools.
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