If the "recent change" included tiller arm, tiller arm to gimble ring shaft, gimble ring, and associated bushings/bearings, then something was less than thoroughly executed on installation. The origional design does leave something to be desired but the later, upgraded parts work very well when installed and maintained properly. --- Jer

jpclear, as far as I know all the parts were changed in order to get rid of the play.It was done by an authortized merc mechanic. Since then there has been one season with the original steering ram and two seasons with the IMCO ram. The play must have been developed during the first year after the change of the gimbal ring. Is there any point in trying to torque the nuts even further?

Still a mystery to me why merc chose a design to a steering system that is prone to develop slack!!??

I know this is an old post but..... I just discovered ther same problem,tiller arm was loose and I also have add on IMCO dual ram steering. I'm thinking that somehow the internal hydraulic cylinder is not properly phased with the external ones and they end up fighting each other somewhat causing stress on the tiller arm. Full hydraulic steering seems like the only cure. I have the dual cable control valve and I noticed that its leaking oil from the cable sleeve where it exits the control valve on the tiller side. Can the control valve be rebuilt? New o-rings etc.? I replaced the upper swivel pin and all the bushings and seals,just dont want to do it again soon.