My 48 inch king kutter brush mower needs blades. At least one of the bolts has the spline stripped. There appears to be a shoulder on the bolt so I can't just cut the head off. I'm thinking I need a giant pipe wrench . Is there a better idea?
Brush mower blade replacement
- Thread starter bucktail
- Start date
I've worked on a few older King Kutter bush hogs, blade changing can take on a life of it's own!
It would be useful to understand which model you are working on, are you trying to remove the bolt that holds the blade to the stump jumper? Is the bolt threaded into the stump jumper or do you have a castle nut on the back (top) of the stump jumper?
The last one I wrestled with was a 60" model, I had a 3/4" drive socket on the castle nut and an 8' cheater pipe to extend my 48" 3/4" drive bar. A super torque driver or torque multiplier might have been a solution, 2 guys on an 8' pipe would not move those nuts. I ended up working through the hole on the top deck and drilling down the side of the castle nut with increasing sized drill bits, then eventually hitting it with a chisel and hammer to break the castle nut apart.
You should be fitting new bolts with new blades, I use some anti seize paste on the new nuts and bolts.
Good luck in these frustrating and time consuming jobs. I now have newer heavy duty Woods rotary cutters that have an easy blade change pin system that you are supposed to be able to change blades in the field, we will see how that works out when the time comes.
Tractor + Attachments = Much Bigger Tools !!
It would be useful to understand which model you are working on, are you trying to remove the bolt that holds the blade to the stump jumper? Is the bolt threaded into the stump jumper or do you have a castle nut on the back (top) of the stump jumper?
The last one I wrestled with was a 60" model, I had a 3/4" drive socket on the castle nut and an 8' cheater pipe to extend my 48" 3/4" drive bar. A super torque driver or torque multiplier might have been a solution, 2 guys on an 8' pipe would not move those nuts. I ended up working through the hole on the top deck and drilling down the side of the castle nut with increasing sized drill bits, then eventually hitting it with a chisel and hammer to break the castle nut apart.
You should be fitting new bolts with new blades, I use some anti seize paste on the new nuts and bolts.
Good luck in these frustrating and time consuming jobs. I now have newer heavy duty Woods rotary cutters that have an easy blade change pin system that you are supposed to be able to change blades in the field, we will see how that works out when the time comes.
Tractor + Attachments = Much Bigger Tools !!
BigG
Well-known member
Equipment
l2501, FEL, BB, Rotary cutter, rake,spreader, roller, etc. New Holland TL80 A
An acetylene wrench works well. Along with a little touch up with a grinder so you can drive the bolt out.
Removed mine for the first time last weekend, a 5:1 torque multiplier made it pretty easy.
Russell King
Well-known member
Lifetime Member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Nothing beats the torque multiplier since you can use it to tighten the bolts using a torque wrench after you use it to break the nuts loose.
Does your mower use some kind of stud for mounting blades? When you say bolt spline I'm picturing wheel studs.
nbryan
Well-known member
Equipment
B2650 BH77 LA534 54" ssqa Forks B2782B BB1560 Woods M5-4 MaxxHaul 50039
If it's (like) the #15bolts/nuts set in drawings below maybe have to order another set and cut them off? Can you remove the stump jumper and torch cut off the frozen bolts? Sounds like some kind of more extreme measures are in order anyway.
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I haven't bought parts yet as I want to bring in the old ones but a new bolt and nut kit was part of the plan from the start. Everything I've read or watched recommends it and I would imagine that the spline is broken so I would need to replace it anyway.
The bolt has a round head with a round shoulder and a single spline formed into the side. I don't have a torch or a plasma cutter. I have angle grinders. It's looking like renting a torch or bringing it somewhere are the best options. Looking at how much torque is needed I don't think a pipe wrench will hold. I could cut flats in the side of the heads to get a regular open end wrench or crescent wrench on it but I'm not sure that's much better. I don't have an 3/=inch impact wrench either.
The bolt has a round head with a round shoulder and a single spline formed into the side. I don't have a torch or a plasma cutter. I have angle grinders. It's looking like renting a torch or bringing it somewhere are the best options. Looking at how much torque is needed I don't think a pipe wrench will hold. I could cut flats in the side of the heads to get a regular open end wrench or crescent wrench on it but I'm not sure that's much better. I don't have an 3/=inch impact wrench either.
Russell King
Well-known member
Lifetime Member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
I would probably grind the head off of the bolt with an angle grinder. Much more delicate than a torch.
Then drive the bolt toward the nut.
If you can get the mower on it’s side and tied to something secure that would make the work much easier to do.
Then drive the bolt toward the nut.
If you can get the mower on it’s side and tied to something secure that would make the work much easier to do.
That would be my preference but the bolt has a shoulder on it. Cut the head off and the shoulder still holds it (I think) Can't get the angle grinder into the counter bore
You might be right. I think the shoulder is in the blade. So I could cut the head off to get the blade off then cut the shoulder off to get the bolt out. A lot of cutting but should be workable.
I thought that's where the term ""cheater pipe"" originated by procuring/utilizing a long piece pipe on breaker bar handle. If you resort to cutting off nut then just drive remnants of bolt out of blade holder frame.
If the spline was holding that plus a little heat might be the ticket. Don't think that a pipe wrench will hold that much torque though. I don't have a torch to cut the nuts off through the access hole. Think I could get in there with an angle grinder if I got the stump jumper off?
Russell King
Well-known member
Lifetime Member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
You may be able to cut the nut side off with a reciprocating saw. I don’t see how an angle grinder would be able to fit. Maybe if it was on its side you would be able to get to it. If you have an oscillating saw or a dremel (and tons of time and patience you may get the nut cut on one side and split open with a chisel. Maybe even drill increasingly large hole at junction of threat to nut inner diameter.
I will look to see how the bolts are interacting with the stump jumper and blades. The blade swings free so I think the nut is tight to the shoulder on the bolt like an axle bolt works. Added by edit: there are significant numbers of various types of bolts and some are single shoulder and some are double shoulder so I can’t be sure that the bolts will drive through if the head is ground off.
If you can get the stump jumper off the blades should come with it. But I have never heard “well that was easy” and “stump jumper removal” in one sentence. It would not hurt to try though.
One other option would be to weld a heavy bar to the bolt head that is long enough to get jammed against the mower frame and then try to break the nut loose.
I will look to see how the bolts are interacting with the stump jumper and blades. The blade swings free so I think the nut is tight to the shoulder on the bolt like an axle bolt works. Added by edit: there are significant numbers of various types of bolts and some are single shoulder and some are double shoulder so I can’t be sure that the bolts will drive through if the head is ground off.
If you can get the stump jumper off the blades should come with it. But I have never heard “well that was easy” and “stump jumper removal” in one sentence. It would not hurt to try though.
One other option would be to weld a heavy bar to the bolt head that is long enough to get jammed against the mower frame and then try to break the nut loose.
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I bought a 3/4 drive impact wrench. I don't have enough air compressor to drive it properly but I got the nuts off plus the one on the pan. Both splines are stripped and the holes are wallered out. Think I'll try to replace the pan barring someone having a brilliant idea on how to shrink the holes
So I figure I'm overdue for an update just in case anyone is interested. I ended up cutting flats in the round heads of the bolts so that a wrench would hold them. My pancake compressor is labeled at 1 hp but is probably more like 1/2hp running, but you can get about a 10-15 second burst out of the Impact wrench with it. One of the blade bolt nuts fought me all the way, so it was a quarter turn, let the compressor catch up, lather rinse, repeat. The other one just needed to be loosened and it came right off.
I ended up replacing the blade pan as well. I welded and ground something that would have held for installation, but not sure about the long term, so I ordered a generic one from agri-supply along with a new castle nut for it. The output shaft nut fought me all the way as well, but I was able to keep the PTO shaft from spinning and take it off with a breaker bar once it was loosened with the impact.
Could not get the old blade pan off. Found out one of my neighbors has a oxy-acetylene torch We cut it smooth in half and it still needed to be pounded off. The heat from the torch must have been the last straw for the seal, because it started to leak, so I ordered a gasket and seal.
Replacing the seal went like one would expect it to go. The blade pan went on easy as well. The only issue that I had with the blades is that I had to hog out the access hole for the blade nuts. It wasn't aligned when I got it, but it was close enough that I could get a socket on and off with the old blade pan. The new one must either have the holes slightly closer to center or be a little more shallow. I could get the socket on with the nut backed off, but once it was tight, it wouldn't come off. I guess I probably should have put the blades on before I put the pan on and it wouldn't have been a huge deal to pull it back off and change the assembly order, but I figured that I'd probably want to be able to pull the blades off in the future, so i opened up the hole.
I ended up replacing the blade pan as well. I welded and ground something that would have held for installation, but not sure about the long term, so I ordered a generic one from agri-supply along with a new castle nut for it. The output shaft nut fought me all the way as well, but I was able to keep the PTO shaft from spinning and take it off with a breaker bar once it was loosened with the impact.
Could not get the old blade pan off. Found out one of my neighbors has a oxy-acetylene torch We cut it smooth in half and it still needed to be pounded off. The heat from the torch must have been the last straw for the seal, because it started to leak, so I ordered a gasket and seal.
Replacing the seal went like one would expect it to go. The blade pan went on easy as well. The only issue that I had with the blades is that I had to hog out the access hole for the blade nuts. It wasn't aligned when I got it, but it was close enough that I could get a socket on and off with the old blade pan. The new one must either have the holes slightly closer to center or be a little more shallow. I could get the socket on with the nut backed off, but once it was tight, it wouldn't come off. I guess I probably should have put the blades on before I put the pan on and it wouldn't have been a huge deal to pull it back off and change the assembly order, but I figured that I'd probably want to be able to pull the blades off in the future, so i opened up the hole.
Back in May I made a comment above in this thread that “blade changing can take on a life of it's own!”. Looks like my comment was spot on, I’ve been down that exact road…..lol
Hopefully you are now ready for years of quality use from your rotary cutter, make sure you have the correct shear pin fitted or slip clutch adjusted correctly.