I bought a Mole Chaser Windmill Model 47987 from Harbor Freight and when i installed in the ground and the wind spun the blades there was no rattleing sound but when i spun the blades by hand and when i tilted it i could hear the ball bearing rolling. Does it have to be installed in the ground as close to level as possible or dose it need a slight slant? Also, do you install the mill next to the mole hole or in the hole?