May be a dumb question but how do you know when it’s time to replace bushings on a a excavator boom or dipper ect
For a dipper end, the only sure way that I know of is to pull the main bucket pin and examine the bushings and pin for wear. Sometimes the bushings wear more on one side than the other. This happened to me; my machine had minimal wear on one side, and the bushing was totally gone on the other. Welding and line boring was needed to repair the dipper end. On some machines, you can adjust the bucket so it hangs free, and you can push on it from side to side to see how much slop there is before going to the trouble of pulling the pin. You may be able to place the bucket on the ground and have someone else operate the boom up and down (slowly) to watch for joint travel on the boom pins.
When you feel it banging when you move the stick back and forth suddenly.
When you can see the arm move sideways