I am looking for information about serial munbers on asv md 70's I have one manufactured in Marcell Mn. It looks like the serial munber is PT 84 0DWDD, A call to a couple of Asv dealers resulted in no success for that serial number. I was wondering if being manufactured in Marcell means that it is an older Asv? There is also an upside down 481P about three inches to the left of the above number Also I was told that if I replace one Danfoss drive motor I had to replace both as there would be problems later on? Is that right?