Just picked up a SQ48-3 bush hog to go behind my Kubota B7200. The hog has got some miles on her but for $300 I thought I would go for it. Gearbox is tight with no leaks which is a positive. I spent some time working on getting the PTO shaft apart, dried grease had glued the two halves together. I had to cut the old broken cover off and once I did I noticed that the shaft was bent on the female side of the slip shaft about 6 inches from the yoke. I thought about getting a piece of drive shaft material and pressing the old piece out to replace it. I did a quick search on Northern tool and see they have new shafts for $99 and that includes the safety cover. I did notice that the shear pin hole on the new shafts are 1/2", the input shaft on the hog has a 3/8" shear pin hole though. Seems that 1/2" is the new standard? Can I just drill out the input shaft?? Is there an easy solution?
Replacement PTO Shaft, Shear Pin Diameter
- Thread starter CJN8
- Start date
ShaunBlake
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Equipment
B6100D; B219; Piranha bar; Hodge stabilizers; Filled Ag rears; R322T w/48" deck
I don't have the technical knowledge or information, yet my machinist training (when I was changing Noah's diapers) makes me averse to boring out the shaft. Why not consider pressing a 1/2" bushing into the input shaft? I'm sure you can find a machine shop (or trade school) to make a couple for you at tiny cost.
Check agrisupply.com, they are generally cheaper than northern, and have a bigger selection. You also need to fit most "off the shelf" shafts, to the application. That means cutting the shaft to the correct length. You cut equal amounts off the male and female ends, not just off one or the other. you don't want it to bind on the shortest length...
Also, you could also make up some bushings to let you use the 3/8 bolt, which may protect your tractor drive-line better than a 1/2" bolt. Just be sure to have an extra, in your toolbox, cause if the bushing is lost, when the bolt shears, you damnsure won't find it in the field...
Also, you could also make up some bushings to let you use the 3/8 bolt, which may protect your tractor drive-line better than a 1/2" bolt. Just be sure to have an extra, in your toolbox, cause if the bushing is lost, when the bolt shears, you damnsure won't find it in the field...
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If your yolks are all good just buy the tubes from your dealer...It is an easy fix. Make sure that you cut enough off of the that they cannot " Bottom out" and damage your tractor.
CJN8
I am a mechanical engineer and after reading your post felt compelled to offer my opinion.
With a B7200 I would be very cautious about too large a shear bolt for fear of having the pto drive assembly damaged.
Certainly not 1/2" and even 3/8" is big.
I asked a friend who has a B7100 with a 48" snow blower and his shear bolt is 5/16" and it never breaks blowing snow and has broken only when the blower inhaled a big rock.
Better to start small and, if you have to, enlarge the hole than being too big and ending up with a destroyed tractor pto.
Dave M7040
I am a mechanical engineer and after reading your post felt compelled to offer my opinion.
With a B7200 I would be very cautious about too large a shear bolt for fear of having the pto drive assembly damaged.
Certainly not 1/2" and even 3/8" is big.
I asked a friend who has a B7100 with a 48" snow blower and his shear bolt is 5/16" and it never breaks blowing snow and has broken only when the blower inhaled a big rock.
Better to start small and, if you have to, enlarge the hole than being too big and ending up with a destroyed tractor pto.
Dave M7040
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With all due respect, a snowblower is not a bush-hog. Snowblowers operate faster, and a tiny rock can sometimes cause big problems. A 3/8 inch bolt is what was in there, so I wouldn't go any smaller. If you want to be extra safe, get the right grade bolt for the bush hog. If NLA, you can stick the bolt in a drill press, and cut a shallow groove with a hacksaw. Not very deep, but at the point where it should break...