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Bret4207

Bevel gear box mystery

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Bret4207
Gentlemen, I somehow ended up with an A/C 312H my buddy had given up on. You guys were kind enough to send me looking in the right direction for parts for the bevel gear box. The parts are on their way, but I have a question or three. 1. When you replace the bevel gears is there a way to do other than "splitting" the tractor like I did? Not that it's a big pain, but if I ever have to do it again and there is an easier way I'd like to know. 2. When I took the gear box apart I found the input shaft from the engine side had the bearing welded (!!!) to the shaft. Obviously someone has been in there before. Why would he weld the bearing to the shaft? 3. How much lash or clearance should the new gears have? Thanks, Bret

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RedbarnRick
Hi, 1. On most of these I have worked on it's just as easy to split the tractor as it is to remove the LH side plate and all theother stuff in your way to access the BGB cover plate. 2. I have seen two BGB that the bearing welded itself to the shaft, the cause was the bearing hold down plate being installed incorrectly 3. 1/16 shim the bearing seal flush to the case. See the post in Resources/Atricles

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BrianP
The only thing I can think of is that the previous owner of your machine thought/observed the shaft spinning without turning the bearing. That would lead me to think the shaft is galled and must be replaced. I can only assume he/she felt welding rods were cheaper than replacing the shaft. I agree with Rick, it’s just as easy to split the tractor and work on the bevel gear box on your workbench. I bought a 7016 off EBay with a blown BGB. Not sure how the previous owner brutalized the machine enough to do this, but replacement was needed. In my case, someone attempted to remove the bearing with a chisel, and ruined the race the bearing sits in. Took me about two hours to split the machine, (I tend to work slowly and methodically), leaving the front half sitting on a pair of shop stands, and the rear half propped up on a cement block and a section of 2x4 I had. As for how much lash the gears should have, nothing was mentioned in the repair manual I used. I assembled the gear box according to instructions and used a shim to make the bearing surface level with the case surface before re-assembly. Hope this helps you out with your repair.

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