08-07-30-026B

File in Section:
Service Bulletin
Bulletin No.:
Date:
07 - Transmission/Transaxle
08-07-30-026B
May, 2013
INFORMATION
Subject:
Information on Slight Vehicle Movement in Park at Start Up After Cold Soak
Models:
2014 and Prior GM Passenger Cars and Light Duty Trucks
Equipped with Automatic Transmission
This bulletin is being revised to add the 2013 and 2014 model years. Customer Information
has also been added. Please discard Corporate Bulletin Number 08-07-30-026A.
Some vehicles may rock or move slightly forward or
rearward while in Park at start up after cold soak. This
condition may be accompanied by a clunk noise. This is
a slight movement that is more often seen visually,
rather than felt, when viewed from the outside and
using the auto-start feature, if equipped.
This slight movement is due to the residual
transmission fluid in the clutch packs that creates a
partial apply on start up. This movement is stopped by
the parking pawl and/or transmission fluid exhausting
completely from the clutch packs.
This condition is normal and no repairs should be
attempted. This can be verified by comparing with
another identically built vehicle under the same cold
conditions.
Customer Information
Please communicate to the customer this condition is a
normal operating characteristic of the vehicle. This
slight movement has no adverse affects on the
transmission. To prevent this condition from occurring,
the parking brake should be utilized as per the Owner's
Manual recommendations anytime the vehicle is
parked. Please share this information with the customer
including a copy of this message.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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