Track wear info.
Mechanics, you need two special tools when you eyeball the tractor's sprocket and track shoes--a wear gage and a track shoe gage. Use them for measurements every 250 hours or quarterly, whichever comes first.
Use Wear Gage
Use drive sprocket wear gage, NSN 5210-01-225-1132, to check sprocket wear on the D7G and D8 tractors:
Set the point of the gage marked for the tractor you're working on between the teeth of the drive sprocket. If the point doesn't touch bottom, the sprocket's OK. If it touches, get support to replace the sprocket.
Track Shoe Gage
Use the broad-based depth gage, NSN 5210-00-221-1902,to measure the height of the grousers. Set the base across two adjacent grousers and measure down lo the plate on the D7s and D8s. If the grouser is less than 1 1/2 inches, replace the shoe.