Exmark commercial 30" tensioner rattle

[Lawnboy18]

Brand new Exmark commercial 30". When I engage the baldes, the tensionner rattles. Once blades are engaged, it's fine. I tried tightening the cable itself that pulls on the tensionner. That didn't help much. Then, I saw that the tensionner would slightly move up and down. Tried tightening that down, but it is very very tight. Any other suggestions?

I allready have the other 30" in the shop. I need this one.

 

[Lawnboy18]

I thought that it would be a good idea to update this.

I went to the shop and talked about the rattle. The mechanic had a look at it with me. He checked all belts and everything seemed fine. There was another unit that had the same problem. He dissassembled everything and checked everything. All was fine. After a good month of use, that unit stopped the rattle. So, I guess it might be a breack in period, but I am not sure. Time will tell.