Tips for rebuilding the hay rake gearbox
DTN / Progressive Farmer’s Ask the Mechanic Columnist Steve Thompson answers readers’ mechanical questions. You can read Steve’s columns monthly in the digital edition of Progressive Farmer (click on the “Resources” tab to find the magazine and inside, the columns from Steve’s Ask the Mechanic).
If you have any questions for him, you can contact Steve at: Write to Steve Thompson at Ask the Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email: mechani @ progressivefarmer .com.
Here’s Steve’s response to a question recently asked by a reader:
READER’S QUESTION: I have a New Holland 258 hay rake and a John Deere 660 hay rake. I remade the 258’s gearbox 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 they don’t work exactly the same. First, I’m having trouble removing the driveshaft from the input shaft so I can change the fork – where the rake driveshaft fits over the gearbox. I have tried removing it with an extractor, but it is difficult. What fixes it to the tree? Do i need a bigger hammer? The next thing is about the lever that disables the rake. I took the entire gearbox assembly out, and I don’t know how to reassemble it so the lever would derail it. On the New Holland, the shift collar lever goes in after the bearing and shaft are installed. I can’t do this with the John Deere. How do I reinstall the front gearbox assembly?
ANSWER FROM STEVE: Yes, these two rake reducers are definitely not designed the same. First of all, the problem you have with removing the driveshaft from the nose of the gearbox seems to be a problem for anyone unfamiliar with this design. The yoke is screwed on the tree. A little different design, but it remains tight. You will more than likely have to heat the yoke to unscrew it. This will likely ruin the oil seal, so you will have to buy a new one. When installing the battery assembly on the Deere, simply leave the fork in a position so that it slides into the shift collar when you insert the assembly. Allow the lever to pivot as the assembly enters the housing. For this gearbox rebuild, the release fork really does not need to be removed.
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