Typically the motor spindle runs in a phosphor bronze bush + this dries out, which causes the speed anomaly ( a once every 20-year service ! ) RX-5000's + 8000's. The motor pulley can also slip down the spindle + physically rub against the motor body ( check you have clearance! )+ produce the same symptom
Remove the motor pulley from the spindle ( 2 x small cheese-headed screws )Flip the motor body upside down and remove the allen keys on the base;this will get you to the base of the motor Take off the motor base + withdraw the armature; the spindle will slide out of the bushing Liberally oil the inside of the phosphor bronze bush with light oil ( I use air tool oil ) + leave to soak in overnight Reassemble + enjoy! While the motor is apart, it might pay to very lightly oil the armature as these are iron + they rust; wipe any excess off + gently blow any grit out of the motor base/top Don't touch the delicate screen printing. This is harder to say, than it is to do
Remove the motor pulley from the spindle ( 2 x small cheese-headed screws )Flip the motor body upside down and remove the allen keys on the base;this will get you to the base of the motor Take off the motor base + withdraw the armature; the spindle will slide out of the bushing Liberally oil the inside of the phosphor bronze bush with light oil ( I use air tool oil ) + leave to soak in overnight Reassemble + enjoy! While the motor is apart, it might pay to very lightly oil the armature as these are iron + they rust; wipe any excess off + gently blow any grit out of the motor base/top Don't touch the delicate screen printing. This is harder to say, than it is to do