Writing a maintenance plan

Down to the last few trivial things before I'm 100% ready to roll with my own numbers and equipment. I'm struggling with the "maintenance plan" that's required for my DOT compliance BS. Is there any standard equipment maintenance programs out there I can use, or any general guidelines? I'm curious how in depth the program has to be. Obviously fluids and tires should have set mileage and measurement limits, but how about things such as the clutch? Do I have to have a written mileage replacement for something like that, or check and replace as necessary? Belts, hoses, engine internal parts? What all needs to be within the maintenance plan? Generally I figured the engine oil would be 20K miles along with the fuel filters, trans and diffs 100K, grease the chassis and driveline 10K, tires when they are down to the DOT wear limits, V-belts when they start to crack, hoses when they're soft or leaking, steering components when they are loose. What else? The truck is a 1997, and naturally the manual is long gone. Does Kenworth still have recommended maintenance intervals available for trucks that old, or are they even worth it?

 

The bearings and liners look like they’re fairly new. The oil pan is off right now, and judging from the internal appearance there isn’t many miles on the last inframe. The bearings were so good that we didn’t bother rolling new ones in.

I planned on 20k miles based on Amsoil’s drain intervals, and doing oil analysis.

It has two fuel filters.

 

We do our company trucks by hours, service every 200. What’s the Cat recommendation for hours?

 

Mine has an hour meter, so I can go either direction.