Fixing a broken clutch on a Cat D4 7U Bulldozer

My friend's Caterpillar D4 dozer main clutch started slipping recently, it was unable to climb a slope or pull a load. We tried adjusting it but something didn't feel right so we stripped it down and found the problem. Check out Pacific Northwest hillbilly's restoration of a similar d4 dozer -    • Caterpillar D4-7U Rebuild   My other channel (Angry Ram) -    • Video