Rear Finish Mower My Woods RM48 blades fall off.

[onowino]

IslandTractor, I don't see any way to use a castle nut.
A 5/8" bolt passes through the blade and screws into the spindle. The spindle has no threaded shaft arbor, or a castle nut would be the answer.

 

[IslandTractor]

IslandTractor, I don't see any way to use a castle nut.
A 5/8" bolt passes through the blade and screws into the spindle. The spindle has no threaded shaft arbor, or a castle nut would be the answer.

I didn't realize it screwed into the arbor. In that case I'd also vote for a tack weld or even JB weld in place of the tack. Should be able to chisel or grind those off pretty easily.

 

[onowino]

I guess this thread has run its course.
Thanks to everybody who contributed their thoughts.
The problem still remains, but I guess it's mine.
Fred

 

[LetsRoll]

I guess this thread has run its course.
Thanks to everybody who contributed their thoughts.
The problem still remains, but I guess it's mine.
Fred

Screw the 5/8" bolt into the spindle housing, only allowing a few threads to be inside of the housing. Take a center punch and put three indentions, one at 10 o'clock, one at 2 o'clock and the last one a 6 o'clock. Then try screwing the bolt in by hand so that you can feel if the bolt takes more tension to screw inside of the housing. If it has more tension on the bolt and you are having a hard time screwing it in. That maybe enough tension to keep the bolt from unscrewing when you install the blade. You can also change the pitch of a few threads on the bolt. That can also help the bolt from unscrewing when in operation.

Bolt thread tension, change the thread pitch which is the angle of the thread (only a few of them) and red lock tite, is going to be your only option to fix this problem. Or you could just sell the mower and buy one for your tractor. Good luck with what you do or try.

 

[onowino]

Thanks LetsRoll, I'll keep that in mind after I've failed with both the blue and red loctite. As to selling it, if I do I intend to tell the prospective buyer the truth about the direction of rotation. It's bad enough I was suckered.
Fred

 

[Hooked_on_HP]

How are you tightening the bolts. If they are grade 5 they should be torqued to 150lbs if grade 8 230lbs. With locktight and proper torque I would think it would hold mowing grass.
Bill

 

[JoeL4330]

interesting problem ...if you are willing to work really hard when you next need to take the blades off, consider some variant (along with loctite) of the following woodworkers trick:

slit the bolt lengthwise some distance with, say, a dremel cutting wheel ...gently insert a slim taper wedge sized so it will bottom out and drive itself into the bolt and expand the threads.

If you decide to consider some variant of this, let me know how/if it works to your satisfaction.

I also thought that the idea of distorting some of the latter threads might work; did you try that?

 

[onowino]

How are you tightening the bolts. If they are grade 5 they should be torqued to 150lbs if grade 8 230lbs. With locktight and proper torque I would think it would hold mowing grass.
Bill

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Well Hooked_on_HP, two points on this subject. (1) I don't own a torque wrench. (2) Since what I'm asking my bolts to do isn't what they were intended to do, all torque specifications are sort of irrelavant.

I've put a 15/16" socket, on an 18" powerhandle and hammered the bolts tight with a 3 pound maul, after applying a liberal coating of blue loctite to the threads which I had already cleaned with gunk and a wire brush, before wiping them dry. I'll let it cure for a couple days and give the grass another try.

If this fails there is still red loctite followed by distorting the threads in combination with red loctite. The ideas, some of which are somewhat destructive, are quite plentiful and each bears some merit. They will each be considered and used in order of least destruction.

In the mean time the grass is getting pretty tall, so I'm glad I divorced the ex when I did.

 

[onowino]

interesting problem ...if you are willing to work really hard when you next need to take the blades off, consider some variant (along with loctite) of the following woodworkers trick:

slit the bolt lengthwise some distance with, say, a dremel cutting wheel ...gently insert a slim taper wedge sized so it will bottom out and drive itself into the bolt and expand the threads.

If you decide to consider some variant of this, let me know how/if it works to your satisfaction.

I also thought that the idea of distorting some of the latter threads might work; did you try that?

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Thanks JoeL4330, for yet another tip. Some of these I would have considered too destructive, but as time goes by, with no success, it will soon be time to try anything. Your comment has been duly noted and put in the list of possible answers in the order of least destruction.
I hope I don't have to do anything that cannot be undone.

 

[RoyJackson]

Have you considered using lockwashers? These keep a tension against the head of the bolt which should prevent loosening.
I'm not a real fan of the star type lockwasher, BTW.