Sorry, have to vent...
I'm supposed to leave for southern California tomorrow for the holidays. I spent this afternoon getting my car ready to go, and after making sure she was happy mechanically, I started cleaning out the interior. I found a screw under the driver's seat...uh oh! I then did some snooping around to see if I could find where the screw came from...and opened up a nice can of worms.
The lower seat assembly on a W123 is put together like this:
The sliders that allow you to adjust the seat up-to-down are bolted to the floor.
The sliders that allow you to adjust the seat front-to-back are bolted to the up-down sliders.
The seat chassis (spring assembly and whatnot) is bolted to the front-back sliders.
The assembly's bolted to the floor with 4 bolts; the others use 3 screws per side (so, 12 altogether not counting the floor bolts). The seat was bolted to the floor without any problems, except that the two rear bolts were rounded out (indicating that someone had removed the seat previously). Of the 12 screws remaining, one was missing (the one I found), two were loose to the point where they weren't doing any good and were allowing the seat to move back and forth (backed out at least 5 or 6 threads worth), and three or four more weren't hand-tight.
So, I now have the seat out of the car and am getting all the screws tight and Loc-Tited in place. This may push my departure time by a day, but OTOH, at least I know why my seat was rocking around now... *sigh*
(the fact that I ran out of Loc-Tite and the impact screwdriver I was using broke, after the hardware store closed, didn't help much either)...