- Engine:
- 3508B (S/N: S2B1-UP; S2E1-UP; 3DM1-UP; 7SM1-UP; 5PS1-UP)
- 3512B (S/N: 8DF1-UP; PWG1-UP; S2G1-UP; S2K1-UP; 1PW1-UP; 2GW1-UP; 3ZW1-UP)
- 3516B (S/N: S2W1-UP; 3CW1-UP)
Description of Change: The sealing capability of the exhaust systems on the above 3500B Engines have been improved.
Adaptable To: Improvements have been made to the 146-3739 Turbocharger Gp, the 207-1352 Turbocharger Gp, and the 129-5488 Exhaust Manifold Gp. The improvements are adaptable to the 3500B Engines that are listed above.
Improvements to the Bellows Assembly
The bellows connect the outlet for the turbine housing to the inlet of the exhaust elbow. The following new parts are used at either end of the bellows.
- Half flanges
- Gaskets
- Locknuts
- High temperature bolts
The new bellows have better surface contact between the mounting face of the half flange and the mounting face of the turbocharger in order to prevent bolts from backing out due to vibration. The new gasket improves the connection between the inlet of the exhaust elbow and the exhaust bellows joint. The new high temperature bolts do not loosen at elevated temperatures. For the changes in the 146-3739 Turbocharger Gp and the 207-1352 Turbocharger Gp, refer to the following tables and illustrations: Table 1, Table 2 and Illustration 1.
Former Parts and New Parts for the 146-3739 Turbocharger Gp     | ||
Former Part     | New Part     | Quantity     |
140-6462 Half Flange     | 188-0471 Half Flange     | 4     |
147-6617 Half Flange     | 188-0474 Half Flange     | 4     |
140-6461 Exhaust Gasket     | 207-1382 Exhaust Gasket     | 4     |
168-7800 Locknut     | 310-2233 Locknut     | 8     |
3B-1915 Bolt     | 6V-6753 Bolt     | 16     |
121-5736 Gasket     | 178-2439 Seal     | 2     |
7L-6443 Bolt     | 300-8579 Bolt     | 8     |
173-2090 Spacer     | 298-6389 Spacer     | 8     |
N/A     | 284-0753 Hard Washer     | 8     |
Former Parts and New Parts for the 207-1352 Turbocharger Gp     | ||
Former Part     | New Part     | Quantity     |
140-6461 Exhaust Gasket     | 207-1382 Exhaust Gasket     | 4     |
168-7800 Locknut     | 310-2233 Locknut     | 8     |
3B-1915 Bolt     | 6V-6753 Bolt     | 8     |
121-5736 Gasket     | 178-2439 Seal     | 2     |
7L-6443 Bolt     | 300-8579 Bolt     | 8     |
173-2090 Spacer     | 298-6389 Spacer     | 8     |
N/A     | 284-0753 Hard Washer     | 8     |
Illustration 1 | g01200262 |
Typical example (1) Bellows that connects the outlet of the turbine housing to the inlet of the exhaust elbow |
Improved Turbocharger Groups are Used
The turbocharger groups have the following improvements:
- A seal has been added between the turbine housing and the bearing housing.
- The turbine housing has a new seal groove.
- The turbine housing is made from a new material with a lower coefficient of thermal expansion.
The new 285-2057 Turbocharger Gp is part of the 146-3739 Turbocharger Gp.
The new 289-8785 Turbocharger Gp is part of the 207-1352 Turbocharger Gp .
New Bolts, Spacers, Washers, and Seals for the Turbocharger Groups
New bolts and spacers are used between the turbine housing and the exhaust manifold. This increases the capability of the bolt to stretch at the joint. Refer to Illustration 2.
Illustration 2 | g01218008 |
(3) Nuts (4) Washers (5) Seal (6) Spacers (7) Bolts |
Tightening Procedure for the Turbocharger to Exhaust Manifold
- Lubricate the threads and the bearing surfaces with 5P-3931 Anti-Seize Compound before assembly.
- Align the joint between the turbocharger and the exhaust manifold in order to install the nuts and the bolts.
- Tighten all of the bolts on the joint to a snug fit.
- Tighten one bolt:
Torque ... 54 ± 5 N·m (40 ± 4 lb ft)
- Tighten a diagonally opposed bolt:
Torque ... 54 ± 5 N·m (40 ± 4 lb ft)
- Tighten the remaining two bolts:
Torque ... 54 ± 5 N·m (40 ± 4 lb ft)
- Repeat steps 4 through 6 in order to verify the torque.
New Nuts, Bolts, and Spacers for the Exhaust Manifold Group
New locknuts, bolts, and spacers are used between the exhaust manifold and the bracket that is connected to the cylinder block. This increases the capability of the bolt to stretch at the joint. The bolts are capable of withstanding higher temperatures. For changes in the 129-5488 Exhaust Manifold Gp, refer to Table 3 and Illustration 3.
Former Parts and New Parts for the 129-5488 Exhaust Manifold Gp     | ||
Former Part     | New Part     | Quantity     |
9S-8752 Full Nut     | 2N-2766 Locknut     | 4     |
3B-1915 Bolt     | 9L-7373 Bolt     | 4     |
NA     | 4P-7680 Spacer     | 4     |
Illustration 3 | g01382953 |
(8) Exhaust manifold (9) Locknuts, bolts, and spacers that connect the exhaust manifold to the bracket (10) Cylinder block |