The 810 was a great washer, except for the 1.5 minute rinse. EXTREMELY flexible washer that can handle anything!
Helical = drive system
Orbital = short stroke transmission type that uses the Helical drive
Pitman = long stroke transmission type that uses the Helical drive
When i say series "10" I was refering to a certain series of the "12" line. There was a tread that had the specs on the change. Unfortunatlly i cant find it The orbital was introduced in 87' at series "10" in the "12" line. IE the 712. None of the "10" line models were produced with orbital, if a 810, 710, 410....etc has an orbital, it was retro-fit
The pair is still for sale. They need to be out by Tuesday. It's posted on craiglist again today. Scott, I vaguely remember the thread you are talking about. It's probably safe to say this is the older, helical drive tranny with the turquoise agitator.
Bobby in Boston