you tighten the motor bracket nuts so much that you bend the motor bracket and make the motor not level!
When you mount you nice PrimeStar dish on a tripod onto plywood in the driveway and forget to put the cinder blocks on it. Then during a thunder storm it blow into the corn field and while rolling across the stone driveway, rips the arm off the dish. No damage to Invacom LNBF though, still using it.