Turntable Bearings

There are different types of bearings that are used in turntables. In the most common type a male shaft rides on a ball inside of a bushing.

Removing the male shaft and looking for uneven wear on the bottom of the shaft, where it contacts the ball, is the place to start. Also remove the ball at the bottom of the well and see if there is any eccentricity or uneven wear. Cleaning it free of oil and rolling it across a glass table can help. It is a bit harder to assess wear in the bushing but once the turntable is reassembled, rock the platter, or sub platter, gently and see if there is any play. Most turntables - though not all - should have very little, or no, play in the bearing.

While you have the darned bearing apart, it might be a good idea to sop up all of the old oil and reoil the bearing in accordance with the manufacturers requirements. You should see no metal debris or filings in the old oil.

Just an FYI, it's much easier to give an accurate answer to these types of questions when the make and model is spelled out.

Good luck and happy listening.

Thanks, maybe I should have been more specific. I'm looking to buy used, I have a 1980 version of a Linn LP12. The lower registers seem a little diffuse now and I'm told thats a symptom of a worn bearing. I can't see it but I can hear it.. So as clarification I'm not asking about obvious wear that's easily observed but instead I am concerned about a used purchase with undetectable wear by the eye. I would try an o-scope but I'm not exactly sure how to set that test up.I also use a stethoscope. I believe that after 40 yrs any bbearing must show wear even if it's unoticiable.
Also people ask for advice and I can't fully establish that a bbearing on an older table is good. Looking at an older Linn doesn't tell you much unless the wear is extensive.
I hhope that helps.

You can easily replace the bearing on an LP12, contact Rick at audioalternative.com, he is a LP12 guru. If anyone knows these tables top to bottom it would be him.

Thanks; still don't see how to check an older bearing though. BTW, Linn doesn't sell older replacement bearings; only the new ones for 1300$

Still might worth a call to Audioalternative as he may have bearings removed when people upgraded. Just a thought, also he can probably tell you what to look for when inspecting yours. Off hand I would say remove the subplatter and clean all the oil from the bearing well and look inside for any roughness and also the end of the shaft. Also as a previous owner of an LP12, if the suspension is not correctly adjusted, the sound quality can be affected greatly. They are a great sounding table but very finicky which is why I sold mine. You haven't mentioned how long you have had the table, so the following may be redundant and no offense is the intent.
A quick test of the suspension is to find the point between the spindle and the tonearm pivot point and quickly tap your finger enough to depress the platter. Then watch the surround of the arm board and see if it bounces in a plane where the gaps around the arm board stay the same. If it shifts in any direction, adjustment is probably needed.