All:
First a tip of the Wheel Horse Cap to our resident Grease Guru, @peter lena, aka Slippery Pete for suggesting this chute upgrade - it works.
I have my faithful 1976 Ariens 10000 series 24" Sno Thro with the manual crank to rotate the discharge chute. I removed the chute, cleaned up the metal mating surfaces and cut a 6" or so diameter glide washer out of a 1/16" thick UHMW plastic sheet, about 7/16" wide. This glide lives on top of the tub and the chute sits on it. Had to make some aluminum small diameter spacers, also 1/16" thick to lower the 3 retainer plates.
Sorry, no pictures, but you get the idea. Lubed up the metal guide tube that centers the chute with silicone spray - no more chunchy jerky motion to rotate the chute - works slicker than jelly on a gold tooth !!
Bill