Mowing 422 Brush Cutter Blade Bolt Broke Again

[KentT]

Yeah. I think it would be a lot easier to replace bolts from the top with an air impact wrench. If it doesn't work and I break more nylon nuts off I can always switch back. The only thing I have to worry about is if the hole I have to cut will weaken the deck. Being a circle it shouldn't be a problem as long as there is adequate metal left on all sides of the hole. If I were to do it, I would also put an access cover on the hole, as the thing really tosses the debris around and I could see filling up the hub pretty easily with dirt and chips. :licking:

Moss,

Being a "shade-tree engineer" since birth, think of something like cutting a plate from the lid of a metal drum where the large filler hole is. Then weld it on top of the deck above the hole you cut to access those troublesome bolts. Simply open that filler cap to access the bolt underneath. That would give you the access plate and a layer of reinforcement at the same time... and these lids are fairly easy for a scrounger to find.

 

[J_J]

Bush hog cutters have had this access hole in the deck to change out the blds as far back as I ca remember. Pages 1 and 11, and 14.

http://www.bushhog.com/ContentFiles/Documents/Manuals/Squealer.pdf

 

[BobRip]

Yeah. I think it would be a lot easier to replace bolts from the top with an air impact wrench. If it doesn't work and I break more nylon nuts off I can always switch back. The only thing I have to worry about is if the hole I have to cut will weaken the deck. Being a circle it shouldn't be a problem as long as there is adequate metal left on all sides of the hole. If I were to do it, I would also put an access cover on the hole, as the thing really tosses the debris around and I could see filling up the hub pretty easily with dirt and chips. :licking:

I was thinking the same thing today after your previous comments. I had the hole saw out and was getting ready to drill. I realized I would need a cover over the hold and had not thought how to do this. I think that you would want to bolt a cover on to strengthen the area and keep grass out. I may do this the next time. I took out the broken bolts today and stayed with the old design. One of the holes was cross threaded so I may be limited in how many times I can fix this without using your method.

Somebody please try this out for us.

 

[BobRip]

I wonder if part of the problem could be that the bolts are working loose and this puts more stress on them, and they break easier. It seems I have to tighten them every 1/2 hour of use. If I got longer bolts and accessed then through the top (drill the big hole) then I might be able to put a lock nut on them at the top.

 

[toy]

Well, I guess I will use an easy out to get the old bolt out. I should probably get some grade 8 bolts to. This bolt had been in there a while, so maybe it's not so bad. I should probably replace the bolts in pairs when one breaks. Still we should give this some thought. We can do better. More suggestions please. What is really the purpose of the spacer? It does not really turn in the blade. Why not just a hole?

If you are talking about a spacer on the bolt that holds the blade on, I would say that the purpose of that is so you can tighten the bolt down that holds the blade without it restricting the blade from kicking back if you hit something that would otherwise break the blade if it didn't have that ability. If the bolts that you are breaking is the bolt that stops the blade when it does fly back, then I don't know about using a harder bolt because I would rather have the bolt fail than mess up the hole in the tub where it goes. If you are talking bout the bolt that holds the blade on then I don't know about that, hope I never have one to break a flying lose blade is a scary thought.

 

[MossRoad]

Bush hog cutters have had this access hole in the deck to change out the blds as far back as I ca remember. Pages 1 and 11, and 14.

http://www.bushhog.com/ContentFiles/Documents/Manuals/Squealer.pdf

Well, there goes my hopes of a patent! :laughing:

Thanks for the link, J_J. That is exactly what I am talking about.

 

[MossRoad]

I wonder if part of the problem could be that the bolts are working loose and this puts more stress on them, and they break easier. It seems I have to tighten them every 1/2 hour of use. If I got longer bolts and accessed then through the top (drill the big hole) then I might be able to put a lock nut on them at the top.

I bought longer bolts and put two jam nuts on the back side for two reasons. One was to prevent what you suggest... the bolt working loose and dropping down. The other reason was when the bolt head breaks off and I toss a blade, I can use a thin wrench on the bottom jam nut to work the threaded stud out of the hub. Of course, all this required removal of the hub (which I am quite good at now :laughing: ). I keep my allen wrench for my lovejoy connector in my PT tool caddy and my impact sockets are always in my garage.

 

[MossRoad]

If you are talking about a spacer on the bolt that holds the blade on, I would say that the purpose of that is so you can tighten the bolt down that holds the blade without it restricting the blade from kicking back if you hit something that would otherwise break the blade if it didn't have that ability. If the bolts that you are breaking is the bolt that stops the blade when it does fly back, then I don't know about using a harder bolt because I would rather have the bolt fail than mess up the hole in the tub where it goes. If you are talking bout the bolt that holds the blade on then I don't know about that, hope I never have one to break a flying lose blade is a scary thought.

Yes, the spacer is just a tad thicker than the blade thickness. That way, you can torque the bolt all the way down and it tightens on the spacer, not the blade. This allows the blade to swing freely.

 

[BobRip]

If you are talking about a spacer on the bolt that holds the blade on, I would say that the purpose of that is so you can tighten the bolt down that holds the blade without it restricting the blade from kicking back if you hit something that would otherwise break the blade if it didn't have that ability. If the bolts that you are breaking is the bolt that stops the blade when it does fly back, then I don't know about using a harder bolt because I would rather have the bolt fail than mess up the hole in the tub where it goes. If you are talking bout the bolt that holds the blade on then I don't know about that, hope I never have one to break a flying lose blade is a scary thought.

I quit using the back stop bolt. Just another thing to break. So what's breaking is the bolt holding the blade on.

I notice that the new spacers are smaller in diameter than the old ones. Today I had a blade hang up (clear with a few hammer taps) and noticed that the washer was bent. This is the one I put on yesterday. The extra gap between the spacer and the blade puts more stress on the washer.I will start using grade 8 bolts and washers now. Maybe a double washer.

 

[KMA]

I swapped out the bolts with grade 8, and then placed a "tire retread spacer" on the extra back stop bolts since one of those broke previously. I picked up a chunk of retread on the highway. Of course, I throttle down before turning the PTO on, but that won't help when you hit something hard when mowing... :|