Trackball on a Lexmark Model M5 is terrible

[bcg]

I have a Lexmark Model M5 that is generally in excellent shape... the entire thing is like perfectly clean, and the caps and outer shell look like they have never been touched.

That said the trackball totally sucks, it squeaks when it rolls in the left-right access and does not register movement reliably.  I don't know the proper terminology for the internals of a trackball but it seems there is some sort sensor mounted on wire spring that is source of the squeaking.

Is the trackball damaged, or do they just suck on these keyboards?  That is, should I buy a new assembly from Unicomp if they have them, or will I just have the same problem?  Or, is there a way I can fix the problem without having to get a new assembly.

Part Number: 1398155
21-NOV-94
Model M5-2

Thanks in advance for any insights or suggestions that you have

[bcg]

bump

[dorkvader]

probably the lame bearing they used on the trackball. I'd like to see a photo of whatever the ball rests on, but my money's on that. I wonder how easy it'd be to replace it with a good ball bearing.