Our old top-load machine runs okay, although sometimes with some high-pitched "chirring" sounds while agitating, for small or medium loads.

Load it up though, and the unit may "stall" (ie., motor just hums). Last time it did this, I advanced the cycle to spin and gave it a jiggle; this time the buzz stopped, the motor kicked in, and the pump-out and spin proceeded.

Not sure what would be "loading" the motor enough to stall it.

I've jumpered the lid switch. I checked the pump for blockage and the drive coupler/rubber isolator. No problems, they look new. Gearcase and clutch were new 3 years ago, look fine, no leaks. Motor looks fine, capacitor is not ruptured or leaking.

Could this be drive block or basket drive / (I think also known as drive tube?)? Could they fail under load and keep motor from turning?

I attach here a couple of photos. Drive block looks okay from here (don't have spanner tool), ears are in notches, no sign of wear.

Also, I did a video of the motor running here
Noisy Kitchenaid (Whirlpool) Direct-Drive Washer Motor - YouTube

See notes in post. What do you think of the noise?

Thanks!!

Thanks very much for your thoughts. After carefully testing the centrifugal start switch, motor, and start capacitor, I thought I'd put it all back together again, run the machine for a week, and see if the "motor stall" turns up again.

After running it this a.m. I know for sure the motor on its Low speed is a little noisy; seems to be one of the bearings.

The gearcase and clutch are just a few years old so I am hopeful they're not the issue. I wouldn't mind replacing the motor. The rest of the machine is in great shape and a new one of similar features would cost quite a bit. This was the absolute top-of-the-line, top-loading direct drive that Whirlpool made back in the day (KitchenAid branded).

Thanks again, will post back if I learn more.

Ok, I will do that! We do need to shop around, I guess... I am assuming prices to be too high. As I mentioned, we have a top-of-the-line unit, and my wife (the laundress) appreciates and uses all the features: Choice of 5 wash water levels; large variety of special cycles; electronic "minutes remaining" display for wash and spin cycles, with "add/subtract a minute per touch" override; really great electronic touch-pad controls with indicator LEDs (still going strong after 25 years!!) My wife will never go back to a mechanical turn-knob timer, that's for sure.

Yeah, I hear you, and in principle I agree. Maybe we have really babied this machine, but, it has been used 4 to 6 times a week for 25 years, and those electronics have done a fabulous job. The only things I've replaced are mechanical: lid switch, gearcase, and drive coupler. Maybe sometime soon the motor.

The matching dryer also is top of the line with electronic controls and the various sensors that go along with them. Again: 25 years, no electronics issues, only mechanical issues. I've replaced the drum rollers and the belt twice, and the gas solenoid once.

I will say this, in the 1980s the boys in St. Joseph were engineering these large machines very, very well!