Mowing Breaking BX Blade Bolts
- Thread starter logdog
- Start date
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OP
logdog
Silver Member
I am able to walk them out with a small chisel. Im getting good at it.
OP
logdog
Silver Member
They are new spring washers. This is the first time I found one after it broke. Usually I cant find the bolt head or washer.
I have had multiple breaks on 2 of 3 blades. The center and shoot side.
This is driving me batty! Like I said, 2 summers with no problems. This is the summer of broken metal!
dodge man
Super Star Member
Go back and read Spyderlk's post. I think he may be on to something. If I follow what he is saying my deck is a 60" deck and my deck has a washer where the inside hole is hex shaped. This goes under the blade. This locks into a hex shape on the end of the spindle. This would help keep the blade bolt from getting any tighter. Yours doesn't have this feature. Think about everytime you start the blades, this may be trying to tighten the bolt until it gets so tight they break.
coveredbridge
Gold Member
This has me puzzled also. I keep looking at those pics to see if there's any clues to what's happening, and I noticed that the blade seems to have an arc, or bow, between the cutting edges. I know my blades are flat. Are those not OEM blades, or is that an optical illusion? Did you change the type of blade you are using this year and could that be causing the problem?
OP
logdog
Silver Member
If the missing hex feature is the problem, why were there no issues for 2 years? I will try and get some more pics when I take the deck off
OP
logdog
Silver Member
They should be kubota blades. The dealer put them on.
coveredbridge
Gold Member
The blades on my 48" mmm are flat in the middle. If your blades are bowed in the middle, and they are new blades, that could be causing the problem. You might want to verify that those are the correct blades for your mower.
Tollster
Veteran Member
Typically a bolt does not fail in the thread engagement area unless there is some sort of manufacturing flaw (You may be able to see some sort of flaw present in the piece you had that led to the failure). All threads are under equal tension, and actually stretch when torqued. If there is any hairline cracks in the bottom of the thread, this could have been created from a forging lap of an imperfection in the metal, or during the machining process, it will crack there. I have seen hairline indications on new bolts.
Over torque of a bolt almost always results in failure in the transition area between the head and the shank, not the engagement area.
I would be willing to say you have a bad batch of bolts.
Over torque of a bolt almost always results in failure in the transition area between the head and the shank, not the engagement area.
I would be willing to say you have a bad batch of bolts.
