Makita 2030 power planer table height

[Myron S. Tanner]

I have had a Makita 2030 planer-jointer since 1982 and it has served me well. Yesterday, the motor was running and I noticed the height adjustment handle slowly creeping in a counter clockwise direction, effectively decreasing the depth of cut. The vibration of the running machine was enough to lower the table. I took the height adjustment assembly apart and tightened the #19 nut on the table end of the large vertical screw. This adjustment seems to be very sensitive and, if it is too tight makes it difficult to crank the table up and down.

Has anyone else had this problem? If so, how did you fix it? Is tightening the #19 nut on the end of the scew the correct adjustment?

Thanks
Myron S. Tanner