Add 200 or 300 lbs to the car. There are ballist weights sent with every job. Rarely ever put on though. From talking to the factory and other sources it comes down to the sheave cut being wrong along with total weight on sheave is not enough. You get an empty car rolling in the overhead or changing the accell or decell and car in the pit. The ropes have a steel core and sit on a boat while there coming over. Check the install prints and look for rope compensation weights. That’s how much weight should be added to the car. Technically then to the counter weight. But. New installation has trouble with the brakes holding on new cars because the pads are not fully seated to drum. Any way try the weight. Has fixed many
Of the traction problems. Also get 126 if one of the brakes are dragging. I would check that also . Happy hunting.