Saltiga Z4500H Oscillation issue

[Kipi]

G'day all. I recently bought an oldish Z4500 and sadly, it has a "click" at the top and the bottom of the oscillation of the spool. I have not opened it but thought that before I do, I should get some pointers from the wise men out there. Is this a "known" repair issue? By that I mean, is it something that happens with wear and is to be expected after years of hard work? Is there anything anyone can share with me on the issue?

I will pluck up some courage in a few days and open the reel. I'll also share my findings and no doubt call for help on the forum.

Thanks in advance.