Ask the Mechanic

Steve Thompson, Contributing Columnist

READER: I have a New Holland 258 hay rake and a John Deere 660 hay rake. I rebuilt the gearbox in the 258 last year and was able to do it myself. However, I am now in the process of rebuilding the gearbox on the John Deere 660. It seems that they do not work exactly alike. First, I am having trouble removing the driveshaft from the input shaft so I can change the yoke -- where the driveshaft from the rake fits on the gearbox. I have tried to pull it off with a puller, but that is difficult. What secures it to the shaft? Do I need a bigger hammer? The next thing is about the lever that throws the rake out of gear. I removed the complete assembly from the gearbox, and I don't know how to put it back together so the lever will throw it out of gear. On the New Holland, the shift collar lever goes in after the bearing and shaft assembly are installed. I can't do that with the John Deere. How do I reinstall the front gearbox assembly?

STEVE: Yes, these two rake gearboxes are for sure not designed the same. First, the problem you are having removing the driveshaft from the nose of the gearbox seems to be a problem for everyone not familiar with this design. The yoke screws onto the shaft. A little different design, but it does stay tight. You will more than likely have to heat the yoke to get it to unscrew. This will probably ruin the oil seal, so you'll need to get a new one. When installing the stack assembly on the Deere, simply leave the fork in a position so it will slip into the shift collar as you insert the assembly. Let the lever pivot as the assembly enters the case. For this gearbox rebuild, the throw-out fork really does not need to be removed.

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-- Write Steve Thompson at Ask The Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email mechanic@progressivefarmer.com

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