Up-down play is determined by the nut on the top of the upper swivel shaft. As you get some ware on the washers, I believe the ring will tend to drop down and you will see some up-down play. Problem is, there is no way to get to that nut short of drilling large holes in the gimbal housing or removing it. I do not believe a little up-down play is a safety issue. Side to side play is a safety issue caused by the ring being lose on the upper swivel shaft. The gimbal ring clamping screws should be retorqued to 55 ft lb as part of annual maintenance to make sure it stays tight (something almost nobody does). Good luck.
