This is too funny. I just took apart my 120 focuser about 10 minutes ago because of the same problem. I fixed most of the slop by first cleaning all the parts in the focuser and re-lubing with superlube. There are two setscrews (very small) on the outside of the focuser that adjust the rear and forward slop in the tube. They do not react as you would think and I had to play with them a bit until I found a satisfactory movement. Unscrew the larger tightening knob all the way while making adjustments to the two setscrews. I did not get all the slop out (probably from age of the focuser) but it cleaned most of it up quite a bit. If you find the tube sticking at certain positions, it is caused by a burr on the tube where the small setscrews can hit. I used fine sandpaper (steel wool might work) to polish off the burr. I then added lube to the entire area that the setscrews come in contact with and started the setscrew adjustment all over. Give it a whirl, you can only improve it over the way it is now.