All the posts say to remove the lower spray arm but I can't figure out how to get it off. None of the videos or photos show this model that has the rising tower in the middle of the spray arm and no screws.
I'm stumped. Thanks,

Thanks for the help! It the tower did just screw off but after 18 years of detergent and hot water it wouldn't budge, even with channel lock plyers which had me thinking this can't be made to unscrew. WD40 finally loosened it up so I could unscrew.

This repair was started because the upper wash arm isn't spinning. I've already cleaned all the detergent debris out of everything down to the chopping blade and it still isn't turning though it seems like plenty of water is coming through the top arm. I've ordered new spray arms, upper and lower, a new pump filter, a new o-ring and new lower spray arm seals/washers.

If that still doesn't fix the problem what next? Do the pumps lose power over time . . . but sure seems like everything is filling fine and draining fine and I believe the water level in the washer is fine. What would an expert do??? I'm trying to keep this dishwasher going until we do a kitchen remodel in one or two years. Thanks for the advice!
Velina in California