Bulletin No.: 24-NA-078

Service Bulletin

Date: May, 2025

TECHNICAL
Subject:

Brand:

Chevrolet
GMC

Intermittent Grinding, Rattle and/or Growling Noise from Under the Vehicle with
Engine Running
Model:

Model Year:
from

to

2023

2024

VIN:
from

Engine:

Transmission:

L3B, L2R

All

to

Colorado
Silverado 1500
Canyon
Sierra 1500

Involved Region or Country

North America, Russia, Middle East, Israel, Chile (West), Colombia (West), Ecuador
(West), Venezuela (West), Japan, Thailand (ASEAN), Singapore, Other Africa, GM Korea

Condition

Some customers may comment on hearing one or more of the following noises from
under the vehicle with engine running (Video Example Above) :
• Grinding
• Rattle
• Growling

Cause

This condition may be caused by the engine starter (Bendix) hanging up and contacting
flywheel while engine is running.
- Technician may be able to duplicate noise and track it to the bell housing area of the
transmission. Noise will be intermittent and erratic.

Correction

Important: Do Not replace the transmission for this intermittent noise in the bell housing
area.
Technicians can diagnose noise by placing a stethoscope or other listening device on
starter motor when concern is happening.
- If the noise has been verified to be coming from the bellhousing area, replace the
starter.

Important: Service agents must comply with all International, Federal, State, Provincial, and/or Local laws
applicable to the activities it performs under this bulletin, including but not limited to handling, deploying,
preparing, classifying, packaging, marking, labeling, and shipping dangerous goods. In the event of a
conflict between the procedures set forth in this bulletin and the laws that apply to your dealership, you
must follow those applicable laws.

Service Procedure
Refer to Starter Replacement.

Copyright 2025 General Motors. All Rights Reserved.

Page 2

May, 2025

Bulletin No.: 24-NA-078

Parts Information
Note: Only select the parts that coincide with the repair performed. Replace the part with the P/N outlined in the
Electronic Parts Catalog (EPC) in accordance with the vehicle VIN.
Causal
Part

Description

Part
Number

Qty

X

STARTER

12730103

1

Warranty Information
For vehicles repaired under warranty, use:
Labor Operation

Description

Labor Time

4041250

Starter Replacement

Use the Published Labor
Operations Time

Version

6

Modified

Released April 24, 2024
Revised June 04, 2024 - Added Sierra to Model section.
Revised June 25, 2024 - Added Rattle Noise to Subject and Condition section.
Revised September 04, 2024 – Added video of condition.
Revised January 07, 2025 - Added GM Korea to Involved Region or Country section.
Revised May 06, 2025 - Add All the Transmission section.

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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