I bought a gravely HD52 (Model 991164) a couple weeks ago and am having the problem with the deck vibrating/rattling. I have taken it now to two different dealers and both consider this "normal". I've seen some people saying the springs are hitting the guards however I had the guards removed last night trying to figure out whats going on and its still making the noise. It seems as the spring/idle pulley on the tension arm are moving way too much. It also seems like there is excessive belt whip coming to and from the crank pulley. The belt also seems to get quite hot in such a short period of time. Just curious if anyone found a cure? I really enjoy this mower it would just be nice to make the noise go away!
Most of my noise comes from the deflector chute. Since I normally leave it in the up position, I'm debating on removing it. However, I'll occasionally drop it down when it's windy to keep stuff from blowing back on me as much.
What I believe it is is poorly manufactured belts. After approximately 20 hours of run time it went away. I manufactured my own own tensioner that was adjustable and got marginally better. If you caliper your belt you will find a thick spot where the cords stop and begin. I think that needs to wear off and it'll go away. I have approximately 70 hours now on my ZT HD and still love it.
