Hi Cat Diesel Scott
Squatch253 is a member here and has done some fantastic videos on a D2 rebuild series.
Here are a few rabbit holes to get you started.
The ACMOC Technical Library has some online manuals for Members.
Be sure to pick up some manuals, eBay usually has a good selection..
Parts Book
Service Manual
Operator and Maintenance Manual
https://www.youtube.com/watch?v=A5iXLUsXmgc
https://www.youtube.com/watch?v=8OT86S6sZtw