Electric Garage Door Opener Problem

[slock1]

I installed a new 3/4 horsepower Craftsman garage door opener. Went well, no problems. Close position set and open position sets well. However, when in the open position, and I push the botton to close the door, the initial motion is extremely bouncy and tourques the arm upwards before continuing on it's path to close.

The mounting is solid and the open position is proper (i.e it is open just short of level and not at a backwards slant).

Is my problem the angle of the arm from the wall to the motor unit? I have a feeling the downward slant is not enough such that the motor unit should be set lower. Or...any other ideas?

Thanks Steve-O

[rloose1]

I had a problem with my door that drove me crazy for a long time. The door would bounce or jump or whatever on the way down. After checking everything I could think of, I asked a professional, and it turned out to be the cable pulleys. They were sticking intermittently, causing the door to be very jerky. Lubed and/or replaced as necessary, and the problem went away. You might want to take a look at your pulleys, if you have a similar system.