Usage:
777B (4YC),
777C (4XJ),
777D (3PR, 2YW),
785 (8GB),
785B (6HK),
785C (5AZ, 1HW),
789 (9ZC),
789B (7EK),
789C (2BW),
793 (3SJ),
793B (1HL),
793C (4AR, 4GZ) Off-Highway Trucks;
776B (6JC),
776C (2TK),
776D (5ER),
784B (5RK) Off-Highway Tractors;
854G (1JW) Wheel Tractors;
D11N (74Z, 4HK),
D11R (8ZR, 9TR, 9XR) Tractors;
992G (7HR),
994 (9YF) Wheel Loaders;
5130 (7TJ, 5ZL),
5130B (4CS),
5230 (7LL) Excavators
All of these machines are powered by 3500 or 3500B engines. All 3500 and 3500B engine crankshaft assemblies include counterweights that are individually machined, after assembly onto the crankshaft, to balance the crankshaft assembly. Because of this, a counterweights' position on the crankshaft is critical. Therefore, all 3500 and 3500B engine crankshaft counterweights are sequentially numbered to uniquely identify each counterweights' position on the crankshaft. These crankshaft counterweight sequence numbers are critical when trying to reassemble a crankshaft assembly.
NOTE: When disassembling and assembling crankshaft assemblies, refer to the Disassembly and Assembly Manual for your application.
Once the crankshaft assembly is balanced, the counterweight sequence numbers are stamped on each respective counterweight. The location and size of these sequence numbers has changed.
Illustration 1.
Former crankshaft counterweight sequence number location. (3512 Crankshaft with Standard Rotation shown.) Front of crankshaft (A). Rear of crankshaft (B). The Standard Rotation direction is counterclockwise when viewed from the rear of the crankshaft.
Formerly, the counterweight sequence numbers were manually stamped below the bottom counterweight bolt hole on the edge of the counterweight as shown in Illustration 1. Note that the sequence numbers are approximately 3/8of an inch tall.
Illustration 2.
Current crankshaft counterweight sequence number location. (3512 Crankshaft with Standard Rotation shown.) Front of crankshaft (A). Rear of crankshaft (B). The Standard Rotation direction is counterclockwise when viewed from the rear of the crankshaft.
Currently, the counterweight sequence numbers are automatically stamped above the top counterweight bolt hole on the edge of the counterweight as shown in Illustration 2. Note that the current sequence numbers are approximately 3/16on an inch tall. Also note the current sequence numbers are preceded by an *.