CARRIER ASSEM. 7L6970 - Caterpillar

Illustration 1 g03111637
Comparison of new D7E and D7R sprockets (A) D7E sprocket, 324-3327 Sprocket Segment (B) D7R sprocket, 314-5462 Sprocket Segment In new condition, the D7E sprocket segment has narrower and shorter teeth than the D7R. Therefore the D7R Custom Track Service (CTS) sprocket wear measurement method and chart cannot be used for the D7E.
Illustration 2 g03112199
D7E sprocket segment teeth worn sharpThe sprocket teeth of low sprocket Track-Type Tractors become visibly narrow and sharp as the sprocket wears. Refer to Illustration 2. This visual wear pattern should not be used to judge sprocket segment replacement. Sprocket tooth height is the primary consideration for sprocket replacement on low sprocket undercarriage.
Illustration 3 g03112319
(C) 57 mm (2.25 inch)D7E sprocket segment replacement is recommended in the following situations:
New sprockets may be needed if tooth height (C) is less than 57 mm (2.25 inch). Sprockets in this condition may begin to experience sprocket and bushing indexing, particularly in moderate to heavy packing applications. If tooth height (C) is less than 57 mm (2.25 inch) and there is no sprocket indexing, then sprockets may continue to be used.
New sprockets are recommended at bushing turn for D7E Heavy Duty Track (fixed bushing). The use of new sprockets on the new wear surface of the turned bushing will provide maximum wear life. D7E machines with Rotating Bushing Track (RBT) should install new sprockets based on tooth height (C) criteria, or whenever a new track is installed.
New sprockets are recommended when new link assemblies are installed. Worn sprockets running against new bushings may accelerate bushing wear.