How much gear lube to add?

[Waterloo]

I use the entire gallon in mine, fresh in frame, CM871, in the heat of the summer I doubt your motor will even know it is there, winter cut back to half a gallon. Also, does it still have the mandate? If it does, I would seriously look into an oil bypass filter to collect the soot. And do an EGR tuneup on her asap along with an overhead if you have yet to do that. Really get into the top of the motor and have a good look see. Just my .02