Power seat motor S420
 

Hi All,
On my '96 S420, when I adjust the Driver's seat for the rear part of the seat to go up, it goes up fine upto a point. At that point, the motor sounds like it skips gears until you let go of the switch. It goes down fine.
I have not even looked under the seat yet, I thought I would start here first.

Are the seat motors repairable, or is it a remove/replace item?
Has anyone here replaced one yet?
Are they seperate motors for each adjustment?

Thank you!