If this is a real Wico leaf stick, then make sure you have both the black plastic washer and the metal washer installed. I've picked up used Wico's before where one or both of them had been removed, probably robbed by an operator to fix another joystick. Also make sure the rubber grommet is installed correctly, it could possibly be installed upside down. When properly assembled, the Wico leaf joystick has very little end float, it is pretty difficult to lift the shaft high enough to cause any type of problem. You may also want to spray a little silicone lube on the end of the shaft before putting it through the grommet if it is sticking.
The base assembly consists of (5) pieces: the base, black plastic washer, grommet, metal washer, and then the cap with the leaf switches. They must be installed in that order, as well.
This photo shows the order the components should be installed in the base, from left to right.

This pic shows the grommet, the tall side goes towards the balltop.

Assembled base, cap not shown.

The shaft assembly consists of (5) pieces: shaft, dust cover, spring, actuator, e-clip. Again, they should be installed in that order, with the grommet being between the dust cover (top of base) and the spring on the underside.

The narrow end of the actuator should be towards the e-clip.
