Usage:
Challenger 75 ( 4CJ ) Tractors;
3176 ( 2YG, 7LG ) Truck Engines
Description of Change: There have been several changes to the fuel injection pump groups. The nozzle cone on the new injectors have a different seat angle for improved interference seating in the brass cylinder head sleeve. Also, the new nozzle cone no longer has a stepped edge.
A new longer bolt (1) and longer spacer (2) are used to fasten the injector to the cylinder head. The new bolt is [70.0 mm (2.76 in)] long verses [60.0 mm (2.36 in)] for the former bolt. The new spacer is [30.0 mm (1.18 in)] verses [20.0 mm (.79 in)] for former spacer. The new longer bolt and spacer allows increased bolt stretch which results in improved injector retention. The new bolt also has a higher installation torque which also results in improved injector retention.
A new teflon coated O-ring seal (3) is used.
Location of fuel injection pump group components.
Adaptable To: The new 5P8347 Bolt (1) and 4P8525 Spacer (2) are direct replacements for the former 8T0100 Bolt and 4P1711 Spacer. The former spacer is canceled. Tighten the new 5P8347 Bolt to a torque of 33 ± 7 N·m (24 ± 5 lb ft).
The new 9X7557 O-Ring Seal (3) is a direct replacement for the former 5P8066 O-Ring Seal. The new seal is effective with 3176 Truck Engine 7LG1125. The new seal should be used as the service replacement in all earlier engines.
The chart lists the new and former injector part numbers and the effectivity.
