Service Replacement Turbochargers

SB - 214 - 019 ( 7/9/04 )

The following charts outline the recommended service replacement turbochargers.  To provide the most durable product available,  it is mandatory that the recommended replacement turbocharger be used.  Unless the recommended replacement turbocharger is the same part number as the failed turbocharger,  it is not acceptable to simply install the same part number as the failed turbocharger.   Mack Trucks,  Inc.  is making every effort to stock the following recommended replacement turbocharger part number in the parts system, and it is requested that these turbochargers be used as replacements.

Before replacing a turbocharger following a turbocharger failure,  the air induction system MUST be cleaned of ANY and ALL debris as outlined in SB - 214 - 015.  Also,  when installing the replacement turbocharger,   the turbocharger oil feed line must be cleaned and the new turbocharger must be pre-lubed as outlined in               SB - 214 - 020.

*  For Wastegate turbochargers that have experienced a wastegate diaphragm failure, DO NOT replace the turbocharger.  A failed wastegate actuator assembly must be replaced with actuator kit part No. 7536 -174307. Kit part No. 7536-174307 includes an improved actuator, and replaces the original actuator kit part No. 7536-173566 effective December 2003.

ASET™ Engines

To determine the proper replacement turbocharger, find the engine model and part number for the turbocharger being replaced. Then, staying within the same row, use the replacement turbocharger part number for the particular chassis model being serviced as given in the Replacement Turbocharger column.

All turbochargers for ASET™ AC engines have the same turbine housing-to-center bearing housing orientation. The only difference in turbochargers for the two chassis models (CX and CH) is the compressor orientation. The ASET™ AC replacement turbochargers within any given boxed-in area of the Service Replacement column of the chart can be substituted for each other by simply re-orienting the compressor cover (refer to the section under the heading "Compressor Cover Reorientation"). It is acceptable to re-orient an ASET™ AC replacement turbocharger if the turbocharger for a particular chassis model is not available.

Compressor Cover Reorientation — ASET™ AC Engines

The following groups of turbochargers are the same except for compressor cover orientation.

• 631GC5171M(X), 631GC5171M2(X) and 631GC5171M7 are the same.

• 631GC5171M3(X), 631GC5171M4(X) and 631GC5171M8 are the same.

• 631GC5171M5(X), 631GC5171M6(X) and 631GC5171M9 are the same.

• 631GC5176M3(X), 631GC5176M4(X) and 631GC5176M10(X) are the same.

• 631GC5176M5(X), 631GC5176M6(X) and 631GC5176M11(X) are the same.

• 631GC5176M7(X), 631GC5176M8(X) and 631GC5176M12(X) are the same.

If required, the above turbochargers can be substituted for each other by re-orienting the compressor cover. This is done by removing the VTG position sensor connector and mounting bracket, loosening the compressor cover V-band clamp and then rotating the compressor cover to the desired position. Be sure that the compressor cover is properly seated (not "cocked"), and then tighten the band clamp retaining nut to 90 lb-ft (10.2 N•m). Install the wire routing clamp onto the band clamp bolt, then install the retaining washer and nut. Tighten the wire clamp retaining nut to 48 lb-ft (5.4 N•m). Take care not to pinch the wires in the clamp. When tightening the clamp retaining nut, ensure that the clamp remains vertical and that the wires do not contact the compressor cover, bearing housing or turbine housing. Reinstall the VTG position sensor connector mounting plate to the three mounting bosses on the outboard side of the compressor cover.

Incorrect wire routing will result in premature failure.

ASET™ AI/AMI turbochargers have different turbine housing to compressor housing orientations for MR and LE chassis models as compared to all other chassis models. Some of these turbochargers can be re-oriented to substitute for the equivalent turbocharger that differs only by orientation, but these must be determined on a case-by-case basis.

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