Here's the latest. I tore down the left side and found no visual defects and then the right side. I then took the whole drive system out and opened up the gear box to find the lube/grease quite dry. This was the first time this unit had been opened up in 15 years, I know this cause I bought it brand new. I cleaned up all the gears and they all seem to be working find.
Next question, what type of grease/lube should be in this gear box?