More on the Vari-flex and Pentas
All -
The Vari-flex was a standard capacity agitator. They considered them 12lb. machines I think? I haven't looked at model parts lists for the 70s Ladies, but I don't think the V-F was used past 1972 or 1973, and I think it had only 5 or 6 years use total. When the Lady K went to the big-tub capacity (18lb.), it no longer could use any of the old agitators and was limited to the Penta-types. The Penta-Vane (five straight vanes) and the Penta-Swirl (five roto-swirl-like vanes) were all Sears had for the big-tubs until the Dual-Action came out in the later 70s. The Penta-swirl was used in the higher line machines, the Penta-Vane in the lower.
I only worked on a couple Vari-Flex equipped machines, but I saw a number of others either waiting to be serviced at other places or in a salvage yard. Each one was either stripped and no longer adjustable or locked in position (usually the most vigorous). I don't know when exact replacements were discontinued by Whirlpool, but by 1990 when I got my start, Sears' solution was to sell you a white Roto-swirl. I put one in a friend of a friend's machine one time replacing the vari-flex that was stripped and would not stay with vanes engaged at any but the weakest setting. The guy later told me his machine hadn't worked as well in years and that must have been a big improvement when they came out with the new agitator! I didn't bother correcting him.