Depends on the skills you have in regard to repairing motors. It's doable, but requires one to pay careful attention since motor is very small. For opening you first need to remove the pulley. Because it's brass, it needs to be heated (with the tip of a soldering iron) so metal expands. Forcing it up will damage the motor. Then the back plate needs to be de-crimped and removed together with rotor. Removing just the plate will damage the brushes. Same is true for re-assembly, these 2 must be put into the case as an assembly. If you have ever opened a big deck type motor, you will know how it's built. This is the same but much smaller. In regard to oiling, problem is the back bushing. Oil will never get there no matter how much you put on the front bearing. However in the front bearing you can add a bit more oil, as it's possible problem is only on the front. If you decide to pursue this motor repair, please take pictures and share them on the forum on a dedicated thread.
Yikes, that sounds quite risky. Thank you for the detailed description! I have opened and cleaned the motors on a Nakamichi DR-8, so I understand the basic concept. I think removing the brass pulley sounds like the trickiest part. I'll let the mechanism run for a bit more to see if it fixes itself, but I think you're right in saying that it's the back bearing. I will post pictures if I decide to pursue the motor disassembly. Thanks again!
Removing the brass pulley is the easiest part in my opinion. Heating it with a soldering iron will expand it enough so it will come off easily. Tricky part, in my opinion, is the disassembly of motor itself in a way that doesn't damage the brushes. Unfortunately it is possible the problem is on the back bearing given from has already been lubed and issue persists. Seen this (the back bearing problem) on JVC full logic walkmans that have a pretty similar motor, but on AIWA not aware of it being a common fault. But it's worth adding a bit more oil on the front bearing before drawing conclusions.
