It is also essential to be sure that the dish is square with the motor shaft. By square, I mean that the center of the dish has to line up exactly with the center of the motor shaft. If you look at the motor and dish from above, and imagine a line drawn across the front of the dish from left to right, and another line going through the motor from front to back, those two lines should form a perfect 'T'. This is especially important to check for on dishes like the WS9036, which use a U-Bolt-style mount, and therefore could be bolted to the motor shaft facing to the left or to the right of dead center.