There is 4 sprockets on drive train... does it still need a chain... In the manual off the internet Model # 944 528 398 it shows 3 sprockets and a chain. Mine is the older model with 4 sprockets

Hi,
I found the manual you found. Your machine is made by Husqvarna for Sears. Perhaps with more info like the engine HP and the width of the thrower, I could find more.
Peace,
Clarke