Ask The Mechanic

Bearing Failing Explained

(Progressive Farmer image by Steve Thompson)

READER: I have bought many Kuhn side cutters, with satisfaction from all of them. But, when I do have a disc problem of a loose turtle (blade holder with a hump), it seems to always be the end turtle. It seems to me that the last turtle with the tower would have less load on it than any other since they do not have to drive other blade holders. What do you think causes the end holder bearings to fail first most of the time?

STEVE: You are right. The end bearings usually fail first. I believe there are three reasons for this early failure. The first reason is caused by the ability of the last disc to contact a rise in elevation of the land, like the side of a terrace, stock tank dam, fire ant bed or hog wallow. This scenario puts an extreme load on the bearings. Adjust the bar float lightly in rough terrain. The second reason is the fact that the outside disc is also loaded with the cut hay that is tossed toward the center of the bar by the tower, allowing a clean swath for the next round. The third reason: Before the operator lowers the bar to begin cutting, the oil in the bar is all on the lower end of the bar. It is important to wait a couple of minutes to allow the bar oil to make its way through the gear train to the end of the bar. Since hay is a "hurry-up" harvest, waiting on anything is not a normal thing we do. For safety reasons, be aware that the curtain blocks much of your vision from the tractor seat. Make sure everyone and everything is clear before lowering the bar; and when making the first round, watch out for those trees and fenceposts. They seem to move into the field, especially on the corners.

READER: I have a 2014 558 John Deere round baler with net wrap. We purchase our net from the dealer and make full 5 x 5 bales. The baler operates great, but about every 25 bales or so, it will tear a slit in the middle of the bale. The next bale will usually be fine. The John Deere dealer said to check the clearance between the rubber roller and the stainless roller. We have done that, and the clearance is correct. Got any ideas?

STEVE: I can think of two things that can cause this problem. The first is that if the bale you are forming is a little too tall, the net can snag and cause this problem. If that is not the case, then I would look for a place on the support (the gate that swings down on the back) where the net could be occasionally hanging. Look in the hinged area where the split is showing up on the bale. Swing the support down and give it a very close look. The net likes to hang on anything it can, like it does when you take something off your truck.

> Write Steve Thompson at Ask The Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email