Revisions to this document are noted
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SUBJECT:

TT6077EN, Rev. B
October, 2013
Page 1 of 2

P2 Carrier Assembly Failures in 1000 and 2000 Series Product Families

MODELS AFFECTED:

International trucks equipped with DT466 engines and Allison 1000/2000 Series Product
Family Transmissions

The purpose of this communication is to identify the necessary steps that ALL authorized Allison Transmission,
Inc. service outlets must follow.

Issue:
P2 Carrier Assembly failures have been linked to excessive torsional activity produced by improper driveline
angularity or engine misfires caused by malfunctioning injectors. In most cases, engine misfires were undetected
by the vehicle operator and engine DTCs (Diagnostic Trouble Codes) were not set. In the cases investigated by
Allison Transmission, Inc., a noticeable improvement in engine performance was observed after the malfunctioning
injectors were replaced.

Action:
Transmissions under warranty:
An Allison Transmission Driveline Analysis must be performed to determine the root cause of a P2 Carrier
Assembly failure. If the driveline meets Allison Driveline Specifications, the engine must be checked at an
International Dealer using their Cylinder Performance Analyzer (CPA) tool.* Other engine analyzers may not
detect malfunctioning fuel injectors.
• Any damage resulting from a driveline irregularity is not the responsibility of Allison Transmission, Inc. and
will not be covered by Allison Transmission, Inc. warranty. If the driveline angularity is found to be excessive,
the customer should be contacted and repairs should be performed at their direction.
• Allison Transmission, Inc. will not accept responsibility for any P2 Carrier Assembly failures related to
engine issues.
Any claim submitted to Allison Transmission must include both a complete Allison Transmission Drivelines Analysis
report and the full CPA report from an International dealership. If both the Allison Driveline Analysis and the
International CPA report indicate that the vehicle is within specifications, Allison will reimburse both procedures.
Transmissions out of warranty:
A Driveline Analysis should be performed to determine the root cause of a P2 Carrier failure. If the driveline
meets Allison Driveline Specifications, the engine should be checked by an International Dealer using their
Cylinder Performance Analyzer (CPA) tool. Other engine analyzers may not detect malfunctioning fuel injectors
that can cause P2 Carrier failures.**

RL

266009

Copyright © 2013 Allison Transmission, Inc. All Rights Reserved.

TT6077EN, Rev. B
October, 2013
Page 2 of 2

NOTE: The customer must be informed that the transmission will likely fail again if the root cause of the
torsional vibration is not addressed by replacing malfunctioning fuel injectors or correcting the driveline
angularity.
* A copy of the CPA Test Results must be attached to the warranty claim requesting reimbursement.
Reimbursement will only be considered if the engine passes the CPA test. If the engine fails the CPA test and is
within International’s warranty period, the cost of the test should be covered by International.
** The customer is responsible for any cost of testing required to determine the root case of the P2 Carrier failure.

Copyright © 2013 Allison Transmission, Inc. All Rights Reserved.