I have a kubota rtv500 had it since late october. I know the rattle sound you are hearin. I have noticed that it is only apparent when driving or riding on the rtv500. This buggy is very qiuet compared to the rangers, rhinos, and mules. The only problem I have with the buggy is that the ride is abit rough. It could use a little speed, but you can only go 10-15 mph in the woods while hunting, and too much faster with cargo ( farming tools) in the back will send things aloft. I hear someone is working on an upgrade to add a little more torque for climbing, but I am not sure of the compnay.
I have also added a system of pulleys to the brush guards, front and rear rollcage crossmembers and to the bed and created a lift for deer, hogs, etc. I simply run my winch cable over the pulleys and anchors away. I pulled 2 deer at once into the bed of the buggy.
I instlled a 3500 milemaker winch on my rtv for 120.00, ( US military uses this company exclusively). vs.the warn 2000/2500 for $475-500.
I am extremely pleased with my rtv, I have pulled a 14ft trailer with a ditch witch mounted up.
I really enjoy this machine
GO KUBOTA