Well, that tells you that when you "load" the mechanism, it is removing the "slack" from all the parts and transferring it to some other parts. I'd seriously look at adjusting the tension rod and relieving the area under the tension adjuster cover so that the rod cannot contact the cover. Once that is eliminated, if you still have the noise, then you will know that's not it. But, it's a fairly common and known condition that is very easily fixed. Also, spending a few dollars on the Pegas blade clamps will take the sloppiness out of the area that is now very loose. When I first heard the knocking noise on my used Dewalt, that's when I decided to dig into it. When I got it apart, I found a very loose bolt back toward the motor on the main drive link. Someone had installed the wrong bolt. I replaced it with the right one and installed it the correct direction. While I was in there, I took it all apart from the rear to the front and cleaned and greased every bearing with the Valvoline synthetic grease. That in itself will go a long way toward removing unwanted sounds. I inspected all of the sleeves and found none that required replacing but I could see where there were many that were dry and would have failed. Do yourself a favor and either do it yourself or have a more mechanically inclined friend help you with it. Your saw will outlive you if you do.