Drive Belt Tensioner Spring Rattle on 2004 Exmark Lazer Z 44hp17ka

[AllisChalmersForever1901]

Hello Everyone! I own the mower posted above; just purchased it last year. The gentleman who originally owned it mentioned one defect that it arrived with straight out of the factory. The tensioner spring for the drive belt rattles against one of the hydro pulleys at mid-low to mid-high throttle. When throttled up all the way no rattle is heard at all, when idling occasionally a loud rattle is heard. Everything else between has a very loud obnoxious rattle. As you can imagine this is extremely annoying and erodes at both the pulley and the spring, but especially the spring. The gentleman also mentioned that he sent it back to the factory for warranty repair and they could not fix the issue. There are now three holes drilled into the frame of the mower to try and better position the anchor point for this spring. None of these work perfectly and I'm not sure if they would be safe to use. I was told that this is how all of these models of mowers were. My question to y’all is:

1. Have any of you had this problem and if so, how have you solved it?
2. Will using a hole drilled in a way so that the spring sits away from the pulley, gets much tighter, and also touches the pivot point of the tensioner bracket be alright or would that cause more issues?

I've attached photos of the original position and in the next post I'll add photos of the new setup. I really need this fixed because I intend to go commercial with this mower.
Thank you very much in advance.

edit: I could not successfully add photos or videos due to their large size and iPhone incompatibility with Windows.

 

[AllisChalmersForever1901]

I have uploaded files to onedrive here:
Lazer Z photos of original spring placement

 

[Tiger Small Engine]

Hello Everyone! I own the mower posted above; just purchased it last year. The gentleman who originally owned it mentioned one defect that it arrived with straight out of the factory. The tensioner spring for the drive belt rattles against one of the hydro pulleys at mid-low to mid-high throttle. When throttled up all the way no rattle is heard at all, when idling occasionally a loud rattle is heard. Everything else between has a very loud obnoxious rattle. As you can imagine this is extremely annoying and erodes at both the pulley and the spring, but especially the spring. The gentleman also mentioned that he sent it back to the factory for warranty repair and they could not fix the issue. There are now three holes drilled into the frame of the mower to try and better position the anchor point for this spring. None of these work perfectly and I'm not sure if they would be safe to use. I was told that this is how all of these models of mowers were. My question to y’all is:

1. Have any of you had this problem and if so, how have you solved it?
2. Will using a hole drilled in a way so that the spring sits away from the pulley, gets much tighter, and also touches the pivot point of the tensioner bracket be alright or would that cause more issues?

I've attached photos of the original position and in the next post I'll add photos of the new setup.
Thank you very much in advance.

edit: I could not successfully add photos or videos due to their large size and iPhone incompatibility with Windows.

When the tensioner pulley rattles against the frame, I have added a piece of hose split and wrapped around the spring and zip tied in the past. May be able to do this for your rattle. Relocating the spring connection point is also an option. Just use common sense on amount of tension on spring and belt.

 

[AllisChalmersForever1901]

When the tensioner pulley rattles against the frame, I have added a piece of hose split and wrapped around the spring and zip tied in the past. May be able to do this for your rattle. Relocating the spring connection point is also an option. Just use common sense on amount of tension on spring and belt.

Well, I’ve already repositioned it and it no longer vibrates against the pulley. However it still makes a lot of noise at mid throttle. I took a video at 240 fps and it almost seems as if there is something that causes the belt to shake. I don’t see it hitting the frame at all. Here is a photo of the spring it’s a pain to remove.
As you can see the pulley is really biting into it.

 

[AllisChalmersForever1901]

I think it’s important that y’all see it first hand. So here are links to the videos and photos.

1. A video of the original rattle
2. A video of the new rattle after repositioning the spring
3. A slow motion video at 240 fps of the new rattle, and several photos of the new position

If you watch the slow motion video you can see the belt seems to flop a lot.

 

[Tiger Small Engine]

I think it’s important that y’all see it first hand. So here are links to the videos and photos.

1. A video of the original rattle
2. A video of the new rattle after repositioning the spring
3. A slow motion video at 240 fps of the new rattle, and several photos of the new position

If you watch the slow motion video you can see the belt seems to flop a lot.

Video would not load. The pulley should never hit the tensioner spring. If the belt tension is not tight enough, consider buying and installing a new spring. You will damage the spring and pulley if you run it like this long term.

 

[ILENGINE]

To me it looks like either something is stuck in the groove of one of the pulleys causing it to bounce or there is a burnt spot on the belt that is thinner than the rest causing the bounce. A third option is there is a damaged pulley that is causing the bounce.

 

[AllisChalmersForever1901]

To me it looks like either something is stuck in the groove of one of the pulleys causing it to bounce or there is a burnt spot on the belt that is thinner than the rest causing the bounce. A third option is there is a damaged pulley that is causing the bounce.

I think it might be a damaged pulley. The belt was changed every year and is brand new now. The spring has been changed once if not several times. This mower has 2,000 hours on it. The engine was rebuilt 200 hours ago. I plan on removing each pulley and inspecting them.

 

[AllisChalmersForever1901]

Video would not load. The pulley should never hit the tensioner spring. If the belt tension is not tight enough, consider buying and installing a new spring. You will damage the spring and pulley if you run it like this long term.

It’s been run like this for over 2,000 hours. I would like to fix it. The pulley is fine, but the spring is taking a beating.