MMM noise

[carlcroom]

Hi all,
I have a BX2360 with a 60" MMM purchased last fall. Since new, at 2400 RPM or above, I get a high pitched noise from the mower. It's not a squeal like metal on metal or a dry bearing. It's more of a whirr, like a blade tip noise. The higher the RPMs, the higher pitched and louder it is. My BIL has said he can hear it from his house 150 yards away. I have checked the obvious things - the gearbox is full, the bearings have been pumped full, and I switched around the blades. Nothing wobbles. With the mower off, there is no noise from the mid PTO.
Has anyone else run across anything like this or have any thoughts?
Thanks

 

[whistlepig]

Does it have an idler pulley that tensions the belt?

 

[Don87]

Hi all,
I have a BX2360 with a 60" MMM purchased last fall. Since new, at 2400 RPM or above, I get a high pitched noise from the mower. It's not a squeal like metal on metal or a dry bearing. It's more of a whirr, like a blade tip noise. The higher the RPMs, the higher pitched and louder it is. My BIL has said he can hear it from his house 150 yards away. I have checked the obvious things - the gearbox is full, the bearings have been pumped full, and I switched around the blades. Nothing wobbles. With the mower off, there is no noise from the mid PTO.
Has anyone else run across anything like this or have any thoughts?
Thanks

Install a radio, and turn it up til the 'whirr' is gone.




Just joking, my Massey does the same thing. It's like a jet taking off, and it is the blade tips hitting the air, and creating the suction to pull the blades of grass up in the air to be cut.

 

[94BULLITT]

Mine sings a little and you can hear the blades.

Here is a video of mine I made with my phone see if yours sounds like that (click on it to play)

 

[DB Pilot]

Carl, I have a BX2200 with a 60" MMM. I have also experienced that whirring noise. Check the nut located at the grease fittings at top or rotors. It might be loose. It is not apparent when installing blades as they will tighten even with that top nut loose. I have had to loctite mine on. Mine is only the left most blade as soon as I hear that sound I have to tighten that nut every time and then it goes away. Hope it isn't your middle blade if this turns out to be the problem.

 

[dougtrr2]

Is the deck clean? I had a mower that would start making a similar noise if the grass built up under the deck.

Take Care,
Doug in SW IA

 

[carlcroom]

Thanks for all the replies. Don87 and 94BULLIT -that's kinda what it sounds like and that's what I was afraid of. As the RPMs get higher, it will give you a headache. My old BX200 and mower did not make this noise.
DB Pilot, I did not think of that and I will check them.

 

[Barneyhunts]

I've had the same problem with the top nut coming loose and it's easy to check!

Carl, I have a BX2200 with a 60" MMM. I have also experienced that whirring noise. Check the nut located at the grease fittings at top or rotors. It might be loose. It is not apparent when installing blades as they will tighten even with that top nut loose. I have had to loctite mine on. Mine is only the left most blade as soon as I hear that sound I have to tighten that nut every time and then it goes away. Hope it isn't your middle blade if this turns out to be the problem.

 

[PsRumors]

I always use a set of foam ear plugs when cutting grass. Makes things so peaceful just riding around.

 

[RaydaKub]

Check the nut located at the grease fittings at top or rotors. It might be loose. It is not apparent when installing blades as they will tighten even with that top nut loose.

Excellent tip. I'll have to look at mine before I mount it again. Thanks!