Just a few notes on adjusting column bearing free play on the Pioneer PL-71 or PL-1400.
I noticed the arm on my turntable was very smooth but did have some free play in the bearing area and this was probably outside the mfr tolerances. The symptom was a slight rocking movement within the column rather than the bearings on the arm tube.
The arm looks similar to one of the early Rega models (made by Acos?) but the bearings, anti-skate and mounting are all completely different.
To fix the problem, I took the arm off the turntable and removed the arm upper bearing and tube from the base column.
Here's a few notes and pictures:
1. First I removed the arm by tipping the turntable upside down (counterweight, headshell and platter removed) on a stack of books to keep the arm above the work surface.
2. Removed the base, desolder the thin tonearm wires. Support the arm from the top then undo the mounting nut.
3. With the arm off the turnable, locate the and removed two black socket headed grub screws in the centre column. Ease the upper assembly and bearing out of the column.
4. The bearing assembly can accessed. To adjust the bearing, slacken the slotted grub screw on the brass nut assembly and turn the nut until the free play has been eliminated. Take care, a little play is better than a binding bearing.
5. Re-assemble taking great care to align the anti-skate leaver with the plastic pin and flattened area of the inner column. It is good to see the arm doesn't have the Rega toothed anti-skate belt but uses a spring mechanism instead.