I recently picked up an SL-1401 for 20 bucks at a garage sale. While I had my concerns given the low price, I figures I couldn't lose in the deal.
After getting it home, I cleaned it up and took a closer look. It came with an old Shure R27ED and Shure RS6E cartridge from back in the vintage Realistic days.
After some quick tests for the usual problem according to internet searches, I cleaned it up and added some 300Kwt silicone oil to the damping piston which solved a fast drop issue.
I then let it run at 33 for an hour, then at 45 for an hour, all with no problems with speed or noise.
I did have to adjust the return control, as it had been effectively shut off, and it works fine now.
However, while doing further tests, on occasion I found that the arm return function would engage immediately while I was trying to place the arm on the first track of a test record. The return was normal, the cartridge raised and lowered properly as though I had pushed to stop button.
It kinda confirmed my suspicions that someone, at some time long ago, had been inside for some reason, possibly a simple bearing lube, and re-engaged the mechanisms incorrectly.
After going through the pots and connectors with a good quality no residue contact cleaner, and some needed lubricant where I could see there had been some, I rotated the spindle several times, and the return mechanism kicked in, much to my surprise.
Through trial and error, I began to understand the circumstances required for this to occur, and finally ran the return mechanism through what should be a normal cycle. After turning the spindle a few hundred times by hand to ensure normal return operations, I replaced the platter.
Now it has returned to normal manual start and automatic return and stop
I'll be comparing it to my Lenco idle drive soon.