Eshetterly93

I was thinking maybe the knee controller potentiometer may be wired badly or needs to be cleaned. I figured it was unlikely the motor is bad. The person I got it from said he took it all apart and cleaned and serviced it. He said he used automotive bearing grease on the gears. I'm thinking I need to get that out of there and replace it with a different grease but I'm not sure which grease to use