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RodinNS
12-10-2005 13:45:08
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Re: Pre-force 3000 - could somebody check a bolt-s in reply to Bob Unitt, 12-10-2005 09:36:22
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Hmmm. I think that somebody's been at that housing before you. 9/16" UNF doesn't sound right to me. I would expect a coarse thread in those holes. I would also expect 6 bolts, but I could be wrong.....
So, you'll need to evaluate what's left of the thread and see if cleaning them up and going with a longer bolt will be enough, or if you're going to need a larger bolt/hole. You would probably get away with a 5/8" UNC. Consult a tap chart for the correct drill size, and drill the hole to the same depth as before. Then run a taper tap, and finish with a bottoming tap to carry the thread down square to the end of the hole. There SHOULD be enough meat in the casting to accomodate the larger hole, but I can't guarntee that. If it were me, I would look hard at cleaning up the thread at the present size if possible, and if that won't suffice, then go to the larger hole size. The last experience I had with this was on a 7710 where I hauled 2 3/4" bolts out and snapped 2 5/8" bolts clean off. I ended up redrilling the 3/4" up to 7/8", and running the full depth up into the housing. The problem is that the factory bolts are an odd length, and if they break or work loose, most people will replace them with a shorter bolt rather than cut a longer bolt to fit. Basically, you must measure the depth of the hole, the thickness of the drawbar housing itself, plus an allowance for washers, and get the length of bolt required. You will no doubt end up getting a longer bolt and cutting it to the exact length, with some degree of trial and error. Just watch them when torquing, and make sure they take torque and tighten the housing, and not just bottom in the hole and leave the housing loose. Watch this carefully. This is a project that will require some degree of ingeniuity. Just use common sense, and be exact with what you do. If this tractor has been lugging heavy downward drawbar loads, then look at the rear of the tractor housing to see if there's 2 good holes below the PTO to install a rear mounting point to the drawbar housing. If there's 2 decent size holes, horizontally in the housing, you can fab a strip to bolt into these holes, and weld it directly to the drawbar housing. This will add a significant amount of support to a housing that is somewhat weakened. This is a repair that I have, and others have done to our 7710's. I know this didn't answer your original question, but hopefully it'll give some general idea of where to go. best of luckRod
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