Quill is hard to move up and down

[Billdog103]

I have an Enco RF45 clone and the quill (Z axis) is hard to move up and down. I haven't used it for a week or 2 and when I tried to use it the actuation is so gummed up that the return spring will not raise it up. I physically have to raise it up. It is so stiff that I can cut without the quill lock engaged.
*The fine adjust is disengaged and spins freely
*the Spindle rotates easy enough
*The Quill lock is disengaged, at least the lever is backed out

I can't imagine from the exploded views what is in there that would cause this.

Anyone have any similar experience or insight? I will take everything apart to find out but I would rather hear some ideas before I start.
Thanks

[HuFlungDung]

I think you'd be wise to take it apart and clean the old grease and crud out. This will also permit you to examine the upper quill for signs of scoring and seizing.

I know on one mill where I had an actual seizing problem, I determined that there was no real good provision to lubricate the quill properly. So I determined where I could drill into the top end to place an oil cup fitting. Drilled the hole, then got my handy dandy carbide ball burr in my die grinder, reached up in there and ground some grooves leading each direction CW and CCW from that hole, to serve as lube distribution channels. Did I mention that it didn't look pretty? But it sure as hell worked good after that.

[Billdog103]

Ok... I took it all apart, cleaned it and greased everything and now it seems to slide freely. I used a lithium based grease. I am wearing "nice clothes" today so I don't think I will be getting up in there to add the oil cup and distribution channels. Maybe if it happens on a Friday next time. Thanks for the reply.
Bill