I've been hearing a chattering under the seat of my Lazer when hot and idled down. Sounded like my hydros cavitating at low RPM. They operated FINE at high RPM though.... Thought it was going to be an expensive May. Turns out, there was debris (wood?) in the grooves of my pump serpentine belt sheave. This caused the belt to jump, which caused the idler to jump. The loose idler was the cause of the noise. I do have to admit, while that idler zerk got grease, but only once or twice did I remove belt tension to do it Before removing the idler assembly, I inspected it. It looked to be bent, so I bought a new one which came with the bushings and zerk already installed. I figured for $11, I'd also replace the idler pulley itself while its off. Also needed was the internal pivot spanner bushing that the bolt goes through. Here's what I ran into. Idler arm itself was NOT bent, but I used the new one anyway as I didn't have new bushings to install into the old arm. Pivot bushing was very worn, as were the internal bushings. Bushings were wet, greasy, and a little rusty in color. The odd part though was where the spring attaches to the idler arm and the frame bolt. Both were severely worn. The bolt was almost worn half way through! Also bad was the serpentine hydro belt. It was cracked in several places. I also re-bushed the rear PTO idler arm while I was at it. Full set of bushings for both idlers was only $10. Now for some pics.... This is the problem....Notice the angle of the idler pulley compared to the rest.