ZT52HD DECK VIBRATION FIX

[Cphillips82]

Got it back last week and mowed some more. The noise is still there but definitely not as bad with all those things tightened up. I can move that same part that you did in the video when the mowers running/blades engaged and it is virtually gone if I hold it in there. I checked the deck plate and that is not an issue for me. I'd like to figure out a way to hold that bar in possibly by tying it around the inside bracket. Have you figured out a way?

 

[Johnny C]

This vid posted on another site shows possible outboard pulley wobble which might be cause of belt movement issue that I have - I'm pulling belts tonight to check

vimeo.com/282133168 that begins with https:// (since I cant yet post links)

 

[Cphillips82]

This vid posted on another site shows possible outboard pulley wobble which might be cause of belt movement issue that I have - I'm pulling belts tonight to check

vimeo.com/282133168 that begins with https:// (since I cant yet post links)

Interesting, definitely let us know. Sure looks like it could be the actual cause. Would it just be replacement of that pulley you think?

 

[handtools]

Got it back last week and mowed some more. The noise is still there but definitely not as bad with all those things tightened up. I can move that same part that you did in the video when the mowers running/blades engaged and it is virtually gone if I hold it in there. I checked the deck plate and that is not an issue for me. I'd like to figure out a way to hold that bar in possibly by tying it around the inside bracket. Have you figured out a way?

I have the same sound from the 60" deck on my Ariens Apex, I could reduce or eliminate the sound by pushing on those bars so I squeezed the brackets together with vise grips to limit the movement of those bars and the noise has subsided almost completely.

 

[Johnny C]

Interesting, definitely let us know. Sure looks like it could be the actual cause. Would it just be replacement of that pulley you think?

Not sure if replacement of pulley is cause and resolves total issue. After a look, I am going to have dealer ( not the purchase dealer but one I found that will actually listen and help) check the bar push in solution and the pulleys / spindles. Will report back

 

[gravelyzthd52]

No resolution yet on this. My dealer has spoken with Gravely and mentioned he wanted to take some measurements but I have not heard back on that yet. I just emailed Gravely and told them I will be requesting a full refund for the mower if this is not resolved soon. This has been going on since May with no fix, not what I expected from Gravely. I guess I should have bought an eXmark, John Deere, anything else.

 

[Johnny C]

My dealer sent their small engine expert and repairman to the house to examine the unit today. He removed an inspected belts, checked blades, spindles and pulleys during two hours of work right in front of me in the driveway. He clearly heard and acknowledged the ringa ringa noise but could find no cause or evidence of it making impacts anywhere or doing damage. At this point I can only take his word and know that they have contacted Gravely ( as have I ) and that I am on record with them both if something significant occurs as a result of this issue later .

This may not be the right or even a good answer - in fact there IS SOMETHING causing the noise - but until Gravely or a more knowledgeable expert can identify it...... I am fumbuzzled.

 

[cpurvis]

It's a design problem. Gravely has unwittingly designed a mower drive system that has a resonant frequency somewhere close to the operating rpm of the mower.

A friend as a new Gravely that has the noise and an old one that doesn't. I bet if the two are compared, we'll see a design change in belts, idlers or tensioners that initiated this problem. Problem is, the two mowers are 150 miles apart right now.

 

[bertsmobile1]

Yep that is all it is, a resonance and understanding them is science at the pHd level.
Can be as simple as the position or length of a weld, the placement of a deck support the thickness of the steel a pulley is made of.
So it will take a while to locate the exact cause and then make sure the fix at A does not create a new bigger problem at B

 

[mhavanti]

Have any of you shortened the belt tension spring to see if that helps alleviate the belt flopping around. From the video, it appears to me the belt resonance is causing all of your metal parts to sing along with the belt tensioner moving back and forth in time. Maybe find a shorter spring before you cut and reshape yours.

Let us know if that brings a halt to the maddening Gravely Clamor.

Max