Modifying the Turbocharger Group on Certain 3500 Marine Engines and 797 and 797B Off-Highway Trucks{1052, 1053} Caterpillar

Engine:

3512 (S/N: 50Y1-UP)

3512B (S/N: PWG1-UP; S2H1-UP; S2J1-UP; S2L1-UP; S2M1-UP; 7HM1-UP; 8EM1-UP; BRN1-UP; 4TN1-UP; 3ZW1-UP; 2EZ1-UP)

3516 (S/N: 29Z1-UP)

3516B (S/N: 8KN1-UP; S2P1-UP; S2S1-UP; S2T1-UP; S2W1-UP; 2FW1-UP; S2Z1-UP)

Off-Highway Truck:

797 (S/N: 5YW1-UP)

797B (S/N: JSM1-UP)

Introduction

Do not perform any procedure that is outlined in this publication until you understand the information that is contained in this document.

This Special Instruction describes modification of the turbine housing in order to use different clamps and bolts. The modification and the use of the clamps and bolts provides a more secure joint between the turbocharger cartridge and the turbine housing.

Required Parts

For each turbocharger, one 369-3232 Turbocharger Kit is required.

Modifying the 234-0836 Turbocharger Gp , 289-0395 Turbocharger Gp , and 365-1409 Turbocharger Gp

The existing bolt holes in the turbine housing must have an additional 2.5 mm (0.098 inch) counter bore. The additional counter boring will allow the use of the new 369-3458 High Temperature Bolts .

Note: Additional turbine housings may be purchased separately. Refer to Table 2 for the appropriate turbine housing for each turbocharger group.

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Illustration 1	g02315833
234-0836 Turbocharger Gp (1) 188-8617 High Temperature Bolts (2) 188-8618 Clamps

1. Remove eight original 188-8617 High Temperature Bolts and two original 188-8618 Clamps from the turbocharger.

2. Separate the turbine housing from the rest of the turbocharger assembly.

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Illustration 2	g02316634
(3) Clamp bolt holes

3. Counter bore the eight clamp bolt holes in the turbine housing to a depth of 2.5 mm (0.098 inch). The counter bore diameter is 10 mm (0.394 inch). The counter bore can be machined with a 10 mm (0.394 inch) drill or an end mill with a 0.5 mm (0.0197 inch) corner radius.

4. Tap the eight clamp bolt holes with a 3/8" - 16 thread tap.

5. Reassemble the turbocharger using the new 369-3458 High Temperature Bolts and 369-3229 Clamps in place of the hardware removed in Step 1

   Note: Apply 5P-3931 Anti-Seize Compound to the threads of the bolts prior to assembly.

   Note: The turbocharger will have longer bolts and thicker clamps that reduce clearance between the bolt head and the cartridge. Use an open-ended wrench or a crowfoot wrench to torque the bolts.

   Torque for the eight high temperature bolts ... 40 ± 2 N·m (30 ± 1 lb ft)