16NA129

File in Section:
-
Bulletin No.:
Service Bulletin
16-NA-129
Date:
October, 2017
INFORMATION
Subject:
Information on Crankshaft Balancer Wobble or Vibration Appearance
Brand:
Model:
Buick
Lacrosse
Model Year:
from
VIN:
to
from
Engine:
Transmission:
to
2017
ATS
Cadillac
CT6
CTS
XT5
Chevrolet
GMC
2016
2017
2018
Camaro
Colorado
HFV6 (RPOs
LGX,
LGW, LGZ)
2016
Acadia
Canyon
2017
Involved Region or Country
North America and N.A. Export Regions
Condition
Some customers may comment that the:
• Crankshaft balancer looks like it is wobbling or vibrating.
• Mounting bolt does not appear to be centered on the balancer correctly.
During PDI this condition may be noticeable.
Cause
This condition may be caused by the crankshaft balancer bolt being painted silver and the
crankshaft balancer being painted black. This gives the illusion that the bolt or balancer is
out of round or vibrating. Also the bolt head may not be concentric with the shank of the
bolt causing a further optical illusion.
Correction
Do not replace any parts. This is purely an optical illusion and does not affect
performance or reliability of the crankshaft balancer or crankshaft balancer bolt.
Version
4
Modified
March 13, 2017 - Updating the Models section.
April 20, 2017 - Adding RPO LGZ to Engine section.
Sept. 25, 2017 - Added 2018 model year.
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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