Ask the Mechanic

Shaft Changes

John Deere 4010 (Progressive Farmer image provided by manufacturer)

READER: I have a 4010 John Deere that has a 540 PTO shaft in it. I use the tractor to run an auger to unload grain out of the wagon and into the grain bins. Is there any way that I can change the 540 shaft to a 1000 shaft? If I could do that, I could idle my tractor engine speed down and not have to run the rpm so fast. Our 4020 has a shaft that comes with the tractor that will change the PTO speed.

STEVE: The 10 Series John Deere tractors, which will include your 4010, could have been ordered with a 1000 shaft when the dealer ordered the tractor. The good news is that you can change the tractor to a 1000, but the bad news is you will have to do a rear split to do that job. After you get the tractor split, the job is easy. Any mechanic around can do that for you, because he has probably been right there before replacing the pin that kept the PTO gears in place before the PTO stopped working on other 4010 tractors.

READER: I converted my old Farmall tractor from a 6-volt to a 12-volt system. I got one of those kits. It charges good, but the amp meter reads negative charge instead of positive charge when I can get it to start. After the change, the tractor is very hard to start. I replaced the 6-volt coil with a 12-volt internal resistance coil and also changed the points and condenser, but it is still hard to start. Got any ideas?

STEVE: Since the tractor shows like it is charging backward on the amp gauge, that tells me you did switch the cables to negative ground. If the tractor were still a positive ground, the alternator would not charge at all. To fix that problem, simply reverse the wires on the back of the amp gauge, and the meter will read correctly. As far as the hard starting, you probably failed to reverse the wires on the coil. More than likely, you put the new coil on just like the old one, which was probably wired for a positive ground system. This is a common mistake when changing polarity of the electrical system. The wire from the switch needs to now be placed on the positive (+) side of the coil, and the negative (-) post wire will go to the distributor. If these two wires were not reversed when you went from a positive ground system to a negative ground system, you only have about half the volts at the spark plug you had before.


We all know that round bales of hay can hurt us in many ways, including rolling over us, falling on us from a stack and even getting us tangled up in the twine or net. However, the most common way around bale accident comes with the help of a tractor and loader. The bale on the tractor is creating a very dangerous setting for a bad accident. Since many round bales weigh around 1,500 pounds, the higher they are carried, the more the center of gravity of the tractor changes, making the tractor much easier to tip over. Smaller tractors of today have big hydraulic pressures and will raise heavy loads. One reason to carry a bale up high comes from double-stacking bales. Another reason is so the driver can see where he or she is going. But, it is best to keep the bale as low as possible, especially during transport. Using a grapple on the loader makes loading round bales much safer, because it keeps the bale from rolling backward off the hay forks -- especially if you are using forks that fit under the bale. If you are using your remotes for loader hydraulic power, it is best not to use a remote with a detent selection to raise the boom position of the loader. This will keep the loader from fully extending on its own power and dumping the bale on your hood -- or you. It takes about 2 seconds for this accident to happen.

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


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