- Engine:
- G3406 SI (S/N: 1RK1-UP)
- G3412 SI (S/N: 3NK1-UP)
- G3408C (S/N: 3WR1-UP; 8YR1-UP)
- G3406 SI TA (S/N: 4FD1-UP)
- G3408 SI TA (S/N: 6NB1-UP)
- G3408B (S/N: 6RJ1-UP)
- G3412C (S/N: 6ZM1-UP)
- G3412 SI TA (S/N: 7DB1-UP)
- G3412C (S/N: 9RR1-UP)
Reference: Engine News, March 1998, Page 8, "New Piston Cooling Jet Tube Assembly Provides Increased Piston Clearance"
Reference: Engine News, December 1998, Page 2, "New Piston Cooling Jet Tube Assemblies Provide Increased Piston Clearance For Engines With Gallery Cooled Pistons"
The initial change was made in order to provide adequate clearance between the piston skirt and piston cooling jet tube assembly. This change is for all of the G3406 Engines that are equipped with the gallery cooled pistons.
There was some confusion when the new piston cooling jet tube assemblies were released. This confusion is the result of the engine division engineering change to the piston cooling jet mounting pads on the G3406 Engine cylinder block. The change to the mounting pad increased the oil flow around the piston cooling jet mounting bolt. This resulted in two different piston cooling jet tube assemblies. The G3406 Engine uses the 155-4011 Tube with the 151-5925 Bolt. This change is effective with G3406 Engines: 4FD1558-UP and 1RK87-UP. See Table 1.
| Effectivity of Piston Cooling Jet Tube Assemblies | ||
| Engine Model | Effectivity of the 155-4010 Tube | Effectivity of the 155-4011 Tube |
| G3406 | S/N:1RK35-86 , S/N:4FD422-1557 |
S/N:1RK87-UP S/N:4FD1558-UP |
| G3408 | S/N:6NB1063-UP S/N:6RJ35-UP S/N:3WR480-UP S/N:8YR812-UP |
|
| G3412 | S/N:7DB853-UP S/N:3NK111-UP S/N:6ZM50-UP S/N:9RR418-UP |
|
Any G3406 (S/N: 4FD1-1557; 1RK1-86) Engines that include gallery cooled pistons should use the 155-4010 Tubes. All G3408 and G3412 Engines that include gallery cooled pistons should use the 155-4010 Tubes. Table 2 lists the effectivity of gallery cooled pistons.
| Effectivity of Gallery Cooled Pistons | |
| Engine Model | Effectivity |
| G3406 | (S/N: 4FD442; 1RK35) |
| G3408 | (S/N: 6NB1063; 6RJ35; 3WR480; 8YR812) |
| G3412 | (S/N: 7DB853; 3NK111; 6ZM50; 9RR418) |