Grading Blade loose on 60" MMM

GregWatkins · Apr 21, 2005

Blade loose on 60\" MMM

One of my blades is loose on my MMM. IF I reach under the deck and try to move the blades by hand, two of the three move together, but the third one (non-discharge side BTW) will move almost freely. I have just sharpened the blades and thats when I noticed it was loose. I read the manual and it mentioned the "cup washers" might cause this issue. My "cup washers" seem fine to me. I only remove one blade at a time so I can be sure that the one I take off is put back on correctly. I also use an impact wrench to remove/install the bolts that hold the blades. The "dust cap" for this particular blade is bent a little so I am wondering if that could cause the problem as well. Any suggestions?

Thanks,

greg

Junkman · Apr 21, 2005

Re: Blade loose on 60\" MMM

take the deck off and examine it. Sounds like you might have a missing key or the blade bolt came loose. Until you look at the blade mounting, you will not know exactly what the problem is. It might be as simple as torquing the bolt, or as difficult as replacing a broken shaft. Too many possibilities to guess what it is......

Buckcreek · Apr 21, 2005

Re: Blade loose on 60\" MMM

On My 54'' deck, one of my blades came loose but it was my falt , I rand over a feed sack in my sisters yard /forums/images/graemlins/mad.gif Didnt do it on purpose but it wraped around the blade and the deck started jumping up and down and befor i could get it shut off the middle blad quit working. I figured i had destroyet the gear box, took the deck off and the bolt on the blade backed off enough to let the blade come loose and quit working. Tightend it up and no problems since that was two summers ago. NOw if she doesnt pick her yard up i dont mow it.

SkyPup · Apr 21, 2005

Re: Blade loose on 60\" MMM

Keep the top bolt on the pulley tightened down with a lock washer as there is a small metal key that fits into the shaft that must be in place to insure rotation.

B2400 · Apr 21, 2005

Re: Blade loose on 60\" MMM

I would check and make sure the cup washers were placed back on properly. If they were put on backwards(inside out?) the they won't apply sufficient pressure to hold the blade firmly in place.

kub4me · Apr 22, 2005

Re: Blade loose on 60\" MMM

I have a B7500 with a 60" MMM and my middle blade came loose on me once. I think that when I tightened my blades I didn't get the shoulder of the sleeve that binds the blade all the way down? I have slept since then and I really can't remember exactly what it was. All I know is that I thought the belt was slipping because when I felt the pulley and the belt they felt warmer than I had expected. /forums/images/graemlins/confused.gif I wish I had known about this site at the time it may have saved me the time of going to get the belt and the cost of it. Glad to know there are good people out there willing to share the wealth ( info).

LBrown59 · Apr 23, 2005

Re: Blade loose on 60\" MMM

( One of my blades is loose on my MMM. IF I reach under the deck and try to move the blades by hand, two of the three move together, but the third one (non-discharge side BTW) will move almost freely. I have just sharpened the blades and thats when I noticed it was loose. I read the manual and it mentioned the "cup washers" might cause this issue. My "cup washers" seem fine to me. 1*I only remove one blade at a time so I can be sure that the one I take off is put back on correctly. I also use an impact wrench to remove/install the bolts that hold the blades. The "dust cap" for this particular blade is bent a little so I am wondering if that could cause the problem as well. Any suggestions?

Thanks,

greg )
***
1* According to the manual on my 60' mower you need to rotate the blades from shaft to shaft. How can you do that by removing only one blade at a time ???