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simple things my grandfather didn't teach me


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I was just about to triumphantly pull the bevel gearbox off the (725) frame when I realized the drive shaft flange needed to come off. The official repair manual assumes simple things like wrestling keys on pulleys and flanges; they just say "remove it." The flange is now loose and the key floats in the keyway. However it doesn't come out. The manual illustrates the key exiting from the gearbox side, which technically doesn't make sense to me, nor have I seen it try to emerge from that side of the flange. The key edges out the drive shaft side, but not easily and not far enough to look like it wants to come out, nor can I push the flange into the gearbox to the extent to clear the key. The shaft looks like it might be damaged to the extent that the key shifts onto it's side when rotated. I can push and pull on it forever, but I would sincerely appreciate your insight and experience in such a simple matter. Thanks! Galen
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Galen, have someone hold something heavy under the shaft, like a 5 lb hammer etc. Thentake a hammer and pin punch and drive the end closest to the case down, this will bring the other end up. When it is up a ways take a small cold chisel and lay it on the shaft flat and drive it under the key and it will lift out. We usually use a very high quality side cutter [Like a Mac or Snap-on] and just bite it on the end as deep in the jaws as it will go, then squeeze hard and pull up on the handles and it will usually pull it right out. There is a dictionary for use with some of them. Good luck, Al E
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Did you remove the set screw that is in flange and tightens against the key..? (It may be covered with grease and crud) If the key has worn so much that it has rolled and is jamming the flange, a tie rod fork has worked for me.
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...No, actually where there should be a single set screw, someone had replaced it with a bolt and added a second to the other side of the flange. The original owner took liberties over the course of time. The set "bolts" are removed and the flange flops around on the shaft. Because the key literally rolls on its side between the flange and the shaft, I'm unable to get either the key to come out or the flange to slide off. I guess a fork mechanism may be in store. Thanks!
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Actually, there wasn't a set screw per se. There were two significant carriage bolts where I would have expected set screws in the side of the flange. Will the shaft shift toward the engine if I remove the bolt inside the gearbox holding it in position? If so, that might give me the added 1/4 inch I need to get a grip on the key to remove it. Can the key only exit towards the engine? I had thought of "prying" the flange off, but have resisted the temptation not knowing the potential consequences.
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By "carriage bolts", I assume you mean the 2 bolts connecting the flange to the driveshaft coupler. Those bolts go through the face of the flange. The set screw is in the side of the flange and tightens against the key to hold the flange in position on the shaft. The set screw may be the recessed hex type (allen screw) that does not have a head protuding above the flange shoulder. Examine that area of the flange very closely. If the bolts you found went through the side of the flange and shaft, someone may have "modified" the tractor during its 40 year life (which is quite possible). Someone may have even welded the flange to the shaft. Most likely, there is a set screw, or the flange is just rusted in place. Prying may damage the flange. That's why I suggested using a fork. The key should fit tightly in matching grooves in the flange and shaft. Therefore, most likely the key cannot be easily pulled from the end. The flange will probably have to be removed before the key can be removed.
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Try to put a bolt in each hole on the flange and tighten them evenly against the frame to remove it kind of like a gear puller works. I had a flange that looked like someone hammered on the BGB. After skinning my knukles for about ten minutes with screwdrivers, prybars, etc..., I came up with this idea which worked great. Hope it helps! PeppyDan
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Gently and evenly prying the flange off the shaft did the trick. I greatly appreciate everyone's help, but not knowing what to expect prevented me from going the brute force route. Unfortunately, pulling the gearbox revealed a sad state of twisted metal and fragments of bearings long gone....the next challenge! What fun! Galen
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