JD 40 Fan Belt Replacement

[saxnbees]

Final update. I never got the nut loose but was barely able to move the entire belt assembly down far enough to replace the belts. The generator belt was fairly easy and straight forward. The fan belt had a couple wrinkles. First, the hand crank mechanism on the JD 40 tricycle model did not leave enough room to fit the belt. The diagram from BeenThere above supplies the answer to that problem. The pin marked number 2 in the diagram needs to be pulled. Then, the starter mechanism can be pushed forward to make room for the belt. Of course you have to clean off years of oil and dirt to be able to find the pin! The pin can probably be left out and is difficult to replace in the mechanism. I was able to replace it using a magnetic wand to hold the pin in position and pushing it on with a long lever. The second problem for me was that the belt mechanism would move no further down given that the nut would not loosen. I was barely able to get the belt over the pulley by turning the fan blade and force the belt on. To help with this, the spark plugs were removed allowing the engine to turn more freely since the crank also needed to turn.

In the end, the operation was more or less a success. The fan belt should not loosen except by stretching since I was unable to move the adjustment down using force. If I need to tighten the belt in the future, the nut and fan assembly can be pried upwards using a pry bar. In that event, something would need to be devised to hold the nut in the new adjustment, maybe a wooden wedge.

 

[DJ54]

I was going to suggest getting a set of jumbo wrenches from Harbor Freight, but they aren't that cheap anymore. I got a set years ago when they were like $29.99. Don't use them all that often but when you need them they are worth their weight in gold. If you know the size, I've seen single wrenches at flea markets pretty cheap because there is only one.

Still, a set of those wrenches are way less than a broken part that would need to be replaced.