I own a 2019 cForce 800 XC. The user manual lists the following information related to oils / lubes.
Items Specifications
Engine Oil SAE15W/40 SG
Transmission oil SAE75W/90 GL-5
Brake Fluid DOT4
Front Gear Case Oil SAE80W/90 GL-5
Rear Gear Case Oil SAE80W/90 GL-5
Grease Pivot Points All Season Grease
Since 15W/40 is hard to come by, 10W/40 is also acceptable.
It does have an internal cartridge style filter and is NOT a screw on type.
I have not had the clutch area open, but it is my understanding it IS a dry clutch.