12-04-21-001B

File in Section:
Bulletin No.:
Service Bulletin
Date:
04 - Driveline/Axle
12-04-21-001B
April, 2013
INFORMATION
Subject:
Transfer Case Identification First Design vs. Second Design
Models:
2007-2013 Cadillac Escalade Models
2007-2013 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2013 GMC Sierra, Yukon, Yukon Denali
Equipped with Magna X2T Transfer Case (RPOs NQF, NQG, NQH or NP0)
This bulletin is being revised to add the 2013 model year, clarify the information from the
previous bulletin and to add data throughout. The document should be reviewed and
treated as new information. Please discard Corporate Bulletin Number 12-04-21-001A
(Section 04 – Driveline/Axle).
The purpose of new product information is to document
important product changes that occur either model
year-to-model year or interim model year.
Changes may include one or more of the following
items:
• Specification changes
• New sealants and/or adhesives
Copyright 2013 General Motors LLC. All Rights Reserved.
•
•
•
•
•
Disassembly and assembly procedure revisions
Mechanical and diagnostic procedure revisions
New special tools required
Interim model year design changes
A component comparison from the previous
model year
Page 2
April, 2013
Bulletin No.: 12-04-21-001B
Interim Model Year Design Change – NQF/NQG/NQH/NPO Front Output Shaft,
Deflector, Seal
2512401
Interim 2012 model year, a new design front output
shaft deflector (3) was implemented into production for
second design NQF–HD/SHD and NQG–HD
applications. First design 2011 model year NQF and
NQG applications can be identified as not having the
deflector on the front output shaft.
For service, the new design front output shaft, deflector
and new design seal may be installed on current and
prior model year Magna NQF–HD/SHD, NQG–LD/HD,
NQH–LD/HD and NP0 applications providing the new
design front output shaft is also installed. The front
output shaft deflector is to be installed using the J 8092
driver handle (1) and DT 50649 seal installer (2).
Bulletin No.: 12-04-21-001B
April, 2013
Page 3
2512403
The new design deflector (1) can be installed onto all
current and prior model year Magna RPOs NQF, NQG,
NQH and NPO applications providing the new design
front output shaft (2) is also installed. Second design
front output shafts can be identified by the machined
area on the OD output end of the shaft (2). First design
front output shafts can be identified by the dust boot
clamp groove (3) located at the OD output end of the
shaft. The new design slinger will NOT install onto the
first design shafts.
Page 4
April, 2013
Bulletin No.: 12-04-21-001B
Service Parts Release Usage Change – NQH/NPO Control Actuator Levers
1817244
Light Duty (LD) 2007-2010 MP3023-NQH and 2010
MP3010-NP0 production transfer cases are built with
LD control actuator levers (3 and 6) and are used with
13 mm (0.52 in) diameter control actuator lever balls (5).
Heavy duty (HD) 2007-2010 MP3024-NQH production
transfer cases are built with HD control actuator levers
(3 and 6) and are used with Heavy 10 mm (0.39 in)
control actuator lever balls.
When replacement of one or both of the LD control
actuator levers is required, it is necessary to replace
both of the levers and all three balls with the HD
components as a set. It is also necessary to
re-measure and adjust clutch pack clearances as
required and to perform the Transfer Case High/Low
Clutch Reset. Refer to Measuring/Adjusting Clutch
Assembly Height in Transfer Case Assemble, Transfer
Case Description and Operation and Transfer Case
High/Low Clutch Reset. Heavy duty (HD) components
are the only parts available for service.
Bulletin No.: 12-04-21-001B
April, 2013
Page 5
Interim Model Year Design Change – NQG High/Low Shift Fork, Fork Pad, and High/
Low Clutch
2714413
Interim 2012 model year the High/Low shift fork, fork
pad and High/Low clutch design changed. The first
design forks (2) can be identified as having three flat
un-notched fork pad areas with three separate fork
pads (1). The second design forks (4) can be identified
as having a half-round shaped pad area with three
notches for pad orientation and installation and upper
and lower half-round fork pads (3). The second design
shift fork (4) and pads (3) are the only design available
for service and must be used with the second design
High/Low clutch.
Interim 2012 model year the High/Low shift fork, fork
pad and High/Low clutch design changed. The first
design high/low clutch (1) can be identified by having a
73 mm (2.87 in) OD rear flange (2). The second design
high/low clutch (3) can be identified by having a
76 mm (2.99 in) OD rear flange (4).
For service:
• The first design 73 mm (2.87 in) high/low clutch
may NOT be used with the second design fork
and pad.
• The second design 76 mm (2.99 in) high/low clutch
must be used with the second design fork and
fork pad.
2714414
Page 6
•
April, 2013
The second design 76 mm (2.99 in) high/low clutch
may also be used with the first design fork and
pad if first design fork replacement is not required.
Interim Model Year Design Change –
NQF/NQG/NQH Front Case Half
Assembly, Input Shaft, Planetary
Carrier High/Low Clutch
Interim 2012 model year for Magna light-duty and
heavy-duty transfer case RPOs NQF / NQG / NQH, a
second-design front case half assembly, planetary
internal gear, gear retaining ring, locking plate, thrust
washer-front, input shaft, pilot bearing, thrust
washer-rear, high/low planetary carrier and high/low
clutch were implemented into second-design
assemblies.
The second-design light duty (LD), heavy duty (HD),
and super-heavy duty (SHD) applications have a
reduced OD dimension carrier and the second-design
planetary internal gear has a reduced ID dimension.
The planetary internal gear is a press-fit
non-serviceable component and must be serviced with
the front case half assembly. In service it is possible
that a new or remanufactured transfer case may
contain first or second-design content.
If a second-design transfer case has been installed into
a vehicle that originally contained a first-design
assembly, TCCM reprogramming is not required.
Bulletin No.: 12-04-21-001B
For production, the following transfer cases variations
were produced:
• 2007-12i Magna LD NQG/NQH – produced with
first-design content. First design service
components are available. A second-design
assembly may be used for back-service in a
first-design application.
• 2007-10 Magna HD NQF – produced with only
first-design content. Service components are
available.
• 2007-10 Magna HD NQG – produced with only
first-design content. Service assemblies may
contain either first or second design content. Both
first and second design service components are
available.
• 2007-12i Magna HD NQH – produced with
first-design content. First design service
components are available. A second-design
assembly may be used for back-service in a
first-design application.
• 2011-12i Magna SHD NQF/NQG – produced with
first design content. First design service
components are available. A second-design
assembly may be used for back-service in a
first-design application.
• 2012i-13 Magna LD NQG/NQH – produced with
second-design content. Second design service
components are available.
• 2012i-13 Magna HD NQH – produced with
second-design content. Second design service
components are available.
• 2012i-13 Magna SHD NQF/NQG – produced with
second-design content. Second design service
components are available.
Bulletin No.: 12-04-21-001B
April, 2013
Page 7
Production Assembly Breakpoints
The design level and component content of the transfer
case can be determined by referencing the assembly
part number located on the identification label.
Production Assembly Breakpoints
Approximate
Production
Breakpoint
First Design
Assembly PN
Second Design
Assembly PN
24256476
24261560
NP0
March 2012
K100 / MYC
24256475
24261517
NQH
January 2012
K200 / MYD
24256474
24261516
NQH
January 2012
K100 / M99
24256473
24261515
NQH
January 2011
K100 / M30
24256472
24261514
NQH
December 2011
K100 / MYC
24257578
24261513
NQF
December 2011
K200 / MYD
24257577
24261512
NQF
January 2012
K200 / 300 / MW7
24257576
24261511
NQF
December 2011
K200 / 300 / MYD
24257581
24261510
NQG
January 2011
K200 / MYD / +Z49
24257580
24261509
NQG
January 2012
K200 / 300 / MW7
24257579
24261508
NQG
December 2011
K200 / 300 / MYD
/ -Z49
24252685
24261507
NQG
December 2011
K100 / M30
24252684
24261506
NQG
January 2011
K100 / MYC
RPO
Vehicle/
Transmission RPO
Page 8
April, 2013
Bulletin No.: 12-04-21-001B
Service Parts List
3216483
Magna Light Duty NQG/NQH/NP0 – First Design
Callout
Description
GM PN
Service Usage
1
Front Case Half Assembly w/gear (2) and ring 3)
19132998
NQH
1
Front Case Half Assembly w/gear (2) and ring (3)
19133000
NQG
1
Front Case Half Assembly w/o gear (2) and ring (3)
19255999
NP0
2
High/Low Internal Gear-Not
serviceable-part of case
assembly
NO/PN
NQG/NQH
3
High/Low Internal Gear
Retaining Ring
19133009
NQG/NQH
4
High/Low Planetary Carrier
Retaining Ring
19132997
NQG/NQH
5
High/Low Locking
Plate-Single tab design
19132996
NQG/NQH
6
Thrust Washer-Front-No tab
design
19132995
NQG/NQH
7
Input Shaft Assembly - w/pilot
bearing
19132977
NQG/NQH-w/M30
7
Input Shaft Assembly-w/pilot
bearing
19132978
NQH-w/M99
NQG/ NQH-w/MYC
Bulletin No.: 12-04-21-001B
April, 2013
Page 9
Magna Light Duty NQG/NQH/NP0 – First Design
Callout
Description
GM PN
Service Usage
7
Input Shaft Assembly-w/pilot
bearing
19255997
NP0-w/MYC
8
Pilot Bearing
19132983
NQG/NQH/NP0
9
Thrust Washer-Rear-No tab
design
19132995
NQG/NQH
10
High/Low Planetary Carrier
Assembly- Three pinion
design
19132986
NQG/NQH
11
High/Low Clutch
19260068
NQG/NQH - w/M30
19260067
NQG/NQH w/MYC and NQH
w/M99
11
High/Low Clutch
3218120
Magna Light Duty NQG/NQH/NP0 – Second Design
Callout
Description
GM PN
Service Usage
1
Front Case Half Assembly w/gear (2) and ring (3)
19299077
NQH
1
Front Case Half Assembly w/gear (2) and ring (3)
19299078
NQG
19299076
NP0
Note: The second design
NP0 front case half assembly
is interchangeable with first
design
1
Front Case Half Assembly –
w/o gear (2) and ring (3)
Page 10
April, 2013
Bulletin No.: 12-04-21-001B
Magna Light Duty NQG/NQH/NP0 – Second Design
Callout
Description
GM PN
Service Usage
2
High/Low Internal Gear-Not
serviceable-part of case
assembly
NO/PN
NQG/NQH
3
High/Low Internal Gear
Retaining Ring
14037953
NQG/NQH
4
High/Low Planetary Carrier
Retaining Ring
15547397
NQG/NQH
5
High/Low Locking Plate- three
tab design
19300745
NQG/NQH
6
Thrust Washer-Front - No tab
design
12470959
NQG/NQH
7
Input Shaft Assembly- w/pilot
bearing
19299085
NQG/NQH-w/M30
7
Input Shaft Assembly - w/pilot
bearing
19299088
7
Input Shaft Assembly-w/pilot
bearing
19255997
NP0-w/MYC
8
Pilot Bearing
19132983
NQG/NQH/NP0
9
Thrust Washer-Rear- Three
tab design
19300746
NQG/NQH
10
High/Low Planetary Carrier
Assembly- Three pinion
design
19299090
NQG/NQH
11
High/Low Clutch
19299092
NQG/NQH - w/M30
11
High/Low Clutch
19299093
NQG/NQH w/MYC and NQH
w/M99
NQH-w/M99
NQG/NQH-w/MYC
Bulletin No.: 12-04-21-001B
April, 2013
Page 11
3216484
Note: 2007-2010 MY Heavy Duty NQF transfer case
assemblies were only produced with first-design
content. Service 2007-2010 MY Heavy Duty NQG
transfer case service assemblies may contain either
first or second design content.
Magna Heavy Duty NQF/NQG/NQH – First Design
Callout
Description
GM PN
Service Usage
1
Front Case Half Assembly
w/gear (2) and ring (3)
19257420
2011-13 NQF
1
Front Case Half Assembly
w/gear (2) and ring (3)
19133000
2007-10 NQG
1
Front Case Half Assembly
w/gear (2) and ring (3)
19259038
2011-13 NQG
1
Front Case Half Assembly
w/gear (2) and ring (3)
19132998
2007-13 NQH
2
High/Low Internal Gear-Not
serviceable-part of case
assembly
NO/PN
NQF/NQG/NQH
3
High/Low Internal Gear
Retaining Ring
19133009
NQF/NQG/NQH
4
High/Low Planetary Carrier
Retaining Ring
19132997
NQF/NQG/NQH
5
High/Low Locking
Plate-Single tab design
19132996
NQF/NQG/NQH
6
Thrust Washer-No tab
design - Front
19132995
NQF/NQGF/NQH
Page 12
April, 2013
Bulletin No.: 12-04-21-001B
Magna Heavy Duty NQF/NQG/NQH – First Design
Callout
Description
GM PN
Service Usage
7
Input Shaft Assembly w/pilot
bearing
19132979
07-10MY NQF/NQG w/MYD
and MW7
7
Input Shaft Assembly-w/pilot
bearing
19257419
2007-13 NQF/NQG w/MYD
7
Input Shaft Assembly-w/pilot
bearing
19259039
2011-13 NQF/NQG w/MW7
8
Pilot Bearing
19259040
2011-13MY NQF/NQG
w/MW7
NQH w/MYD
2007-10MY NQF/NQG/NQH w/ MW7 / MYD
8
Pilot Bearing
19132984
2007-13 NQH w/MYD
2011-13 NQF/NQG w/ MYD
9
Thrust Washer-No tab
design-Rear
19132995
10
High/Low Planetary Carrier
Assembly-Five pinion design
19132987
11
High/Low Clutch
19260067
NQG/NQH
2011-13 NQF
NQG/NQH
2011-13 NQF
NQG/NQH
2011-13 NQF
3218121
Bulletin No.: 12-04-21-001B
April, 2013
Page 13
Magna Heavy Duty NQF/NQG/NQH – Second Design
Callout
Description
GM PN
Service Usage
1
Front Case Half Assembly
w/gear (2) and ring (3)
19299079
2011-13 NQF
1
Front Case Half Assembly
w/gear (2) and ring (3)
19299078
2007-10 NQG
1
Front Case Half Assembly
w/gear (2) and ring (3)
19299080
2011-13 NQG
1
Front Case Half Assembly
w/gear (2) and ring (3)
19299077
2007-13 NQH
2
High/Low Internal Gear-Not
serviceable-part of case
assembly
NO/PN
NQF/NQG/NQH
3
High/Low Internal Gear
Retaining Ring
14037953
NQF/NQG/NQH
4
High/Low Planetary Carrier
Retaining Ring
15547397
NQF/NQG/NQH
5
High/Low Locking Plate-Two
tab design
15664905
NQF/NQG/NQH
6
Thrust Washer-No tab
design - Front
12470959
NQF/NQGF/NQH
7
Input Shaft Assembly-w/pilot
bearing
19299086
07-10MY NQG w/MYD
and MW7
7
Input Shaft Assembly-w/pilot
bearing
19299087
2011-13 NQF/NQG w/MYD
7
Input Shaft Assembly-w/pilot
bearing
19299089
2011-13 NQF/NQG w/MW7
8
Pilot Bearing
19259040
2011-13MY NQF/NQG
w/MW7
NQH w/MYD
2007-10MY NQF/NQG/NQH w/ MW7 / MYD
8
Pilot Bearing
19132984
2007-13 NQH w/MYD
2011-13 NQF/NQG w/ MYD
9
Thrust Washer-Two tab
design-Rear
15547390
10
High/Low Planetary Carrier
Assembly-Six pinion design
19299091
11
High/Low Clutch
19299093
NQG/NQH
2011-13 NQF
NQG/NQH
2011-13 NQF
NQG/NQH
2011-13 NQF
Page 14
April, 2013
Bulletin No.: 12-04-21-001B
Front Case Half Identification
2778675
The first design front case half assembly can be
identified as having an internal gear that is a 94 tooth
design with an inside diameter (a) of
148.5 mm (5.85 in).
The second design front case half assembly can be
identified as having an internal gear that is a 91 tooth
design with an inside diameter (a) of 142 mm (5.59 in).
Bulletin No.: 12-04-21-001B
April, 2013
Page 15
Input Shaft Identification
2778674
The first design input shaft can be identified as a
56 tooth design with an outside diameter (a) of
91.4 mm (3.60 in).
The second design input shaft can be identified as a
53 tooth design with an outside diameter (a) of
87.50 mm (3.44 in).
Page 16
April, 2013
Bulletin No.: 12-04-21-001B
High/Low Planetary Carrier Assembly Identification
3216481
The first-design light-duty 3-pinion high/low planetary
carrier (1) can be identified as having a 30 tooth design
with an inside diameter (a) of 61.3 mm (2.41 in). In
addition, the first-design carrier can also be identified
by the presence of a recessed washer pocket (3) at the
rear thrust washer location.
The second-design light-duty 3-pinion high/low
planetary carrier (2) can be identified as having a
29 tooth design with an inside diameter (b) of
60.2 mm (2.37 in). In addition, the second-design carrier
can also be identified by the lack of a recessed washer
pocket (4) at the rear thrust washer location.
Bulletin No.: 12-04-21-001B
April, 2013
Page 17
3216478
The first-design heavy-duty 5-pinion high/low planetary
carrier (1) can be identified as having 5 pinions and a
30 tooth design with an inside diameter (a) of
61.3 mm (2.41 in).
The second-design heavy-duty 6-pinion high/low
planetary carrier (2) can be identified as having 6
pinions and a 29 tooth design with an inside diameter
(b) of 60.2 mm (2.37 in).
Page 18
April, 2013
Bulletin No.: 12-04-21-001B
High/Low Clutch
2778672
The first design high/low clutch can be identified as
having a 30 tooth design with a gear tooth outside
diameter (a) of 65.50 mm (2.58 in).
The second design high/low clutch can be identified as
having a 29 tooth design with a gear tooth outside
diameter (a) of 63.25 mm (2.49 in).
Bulletin No.: 12-04-21-001B
April, 2013
Page 19
Component Replacement – Conversion from First Design to Second Design
2787432
It is possible to repair a first-design assembly using
second-design components. Refer to the parts catalog
and the tables above for component part number
clarification.
Note: First-design LD components are shown in the
view above.
When servicing a first-design assembly with
second-design components, the following components
MUST be replaced as a group:
1. Front Case Half Assembly – with internal gear and
retaining ring
2. Locking Plate
3.
4.
5.
6.
7.
8.
Thrust Washer (front)
Input Shaft
Pilot Bearing
Thrust Washer (rear)
Planetary Carrier Assembly
High/Low Clutch
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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