18NA355

Bulletin No.:
Service Bulletin
Date:
18-NA-355
March, 2019
TECHNICAL
Subject:
Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH
(40 and 128 KM/H) at Steady Speed
Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East
Operations (MEO). Mexico and Export Regions should follow Bulletin 19-NA-018.
Model Year:
Brand:
Model:
Chevrolet
GMC
to
Transmission:
(8L45, 8L90
Automatic)
to
2016
2019
LCV, LGX, LTG,
LT4, LF4
M5N, M5T, M5U
CT6
2016
2018
LGX, LGW, LTG
M5N, M5X
Escalade
Models
2015
2017
L86
M5U
Camaro
2016
2019
LGX, LTG, LT1
M5T, M5U
CTS
from
Engine:
(2.0L, 2.5L, 3.0L,
3.6L, 5.3L, 6.2L)
from
ATS
Cadillac
VIN:
Colorado
2017
2019
LGZ
M5T
Corvette
2015
2019
LT1, LT4
M5U
Silverado
Models
2015
2018
L83, L86, L8B
M5U, M5X
Canyon
2017
2019
LGZ
M5T
Sierra
Models
2015
2018
L83, L86, L8B
M5U, M5X
Yukon
Models
2015
2017
L86
M5U
Involved Region or Country
United States, Canada, Middle East Operations (MEO)
Condition
Some customers may comment on any of the following conditions:
• A shake and/or shudder during light throttle acceleration between 25 and 80 mph
(40 and 128 km/h) steady state driving when transmission is not actively shifting
gears.
• A shudder feeling that may be described as driving over rumble strips or rough
pavement.
Shudder feeling is evident in both Drive and M7 (MY15-16) and L7 (MY17/MY18) mode.
Diagnosis Instructions
To ensure TCC Shudder is diagnosed correctly, please
drive the following schedule on a smooth road with
transmission sump temperature between
122°F (50°C) - 158°F (70°C).
Important: For some road conditions, it may be
required to apply the brake pedal and throttle
simultaneously to stay within desired gear, engine firing
mode, engine torque range, and engine/vehicle speed
ranges.
Copyright 2019 General Motors LLC. All Rights Reserved.
For Full Size Trucks/SUVs - Press and hold the
tow-haul mode button for 5 seconds to disable grade
braking to prevent downshifts during test.
Run the following tests for 3 operational modes:
A. Normal Operation (GDS2 for viewing only)
B. GDS2 Commanding TCC in Disabled Operation
(TCC Open)
C. GDS2 Commanding TCC in Enabled Operation
(TCC Locked)
Page 2
March, 2019
Bulletin No.: 18-NA-355
Shudder Test
Refer to the table below for conditions pertaining to
specific applications. In each vehicle, constant throttle
input on a smooth grade is desirable. PicoScope
Measured Frequency is the approximate vibration
frequency where TCC Shudder can be found,
discussed in detail below.
Vehicle Information
Shudder Test Conditions
PicoScope
Vehicle
Speed
mph
(km/h)
Engine
Torque
(Nm)
Measured
Frequency
(+/- 2 Hz)
1100-1500
42-55
(67-88)
100250
23
V4
1100-1500
42-55
(67-88)
100250
23
8
V8
1000-1500
42-62
(67-99)
200375
28
M5T
8
V4
1100-1500
42-55
(67-88)
100250
23
LGX
M5N
8
V6
1100-1500
42-55
(67-88)
100250
23
4 CYL.
Turbo
LTG
M5N
8
V4
1100-1500
42-55
(67-88)
100250
23
ATS-V
6 CYL.
Twin
Turbo
LF4
M5U
8
V6
1100-1500
42-55
(67-88)
150300
26
Cadillac
CT6
6 CYL.
Twin
Turbo
LGW
M5X
8
V6
1100-1500
42-55
(67-88)
150300
26
Cadillac
CT6
6
CYL. NA
LGX
M5N
8
V6
1100-1500
42-55
(67-88)
100250
23
Cadillac
CT6
4 CYL.
Turbo
LTG
M5N
8
V4
1100-1500
42-55
(67-88)
100250
23
Chevrolet
Camaro
6
CYL. NA
LGX
M5T
8
V6
1100-1500
42-55
(67-88)
100250
23
Chevrolet
Camaro
4 CYL.
Turbo
LTG
M5T
8
V4
1100-1500
42-55
(67-88)
100250
23
28
Make
Application:
Engine
Type
Engine
RPO
Trans
RPO
Gear
Engine
Mode
(V4,
V6, V8)
Transmission
Input
Speed
(rpm)
Cadillac
CTS
6
CYL. NA
LGX
M5N
8
V6
Cadillac
CTS
4 CYL.
Turbo
LTG
M5N
8
Cadillac
CTS-V
8 CYL.
Supercharged
LT4
M5U
Cadillac
ATS
4
CYL. NA
LCV
Cadillac
ATS
6
CYL. NA
Cadillac
ATS
Cadillac
Chevrolet
Camaro
SS
8
CYL. NA
LT1
M5U
8
V4/V8
1000-1,500
40-55
(64-88)
(V4)
100200
/(V8)
175375
Chevrolet
Corvette
8
CYL. NA
LT1
M5U
8
V4 (Eco
Driving
Mode)
1000-1800
40-80
(64128)
125250
28
Chevrolet
Corvette
Z06
8 CYL.
Supercharged
LT4
M5U
8
V4 (Eco
Driving
Mode)
1000-1800
40-80
(64128)
125250
28
Chevrolet/
GMC
Silverado/
Sierra
8
CYL. NA
L83
M5U
8
V8
1050-1500
45-55
(72-88)
200375
26
Chevrolet/
GMC
Silverado/
Sierra
8 CYL.
NA BAS
L8B
M5X
8
V8
1050-1500
45-55
(72-88)
200375
26
Bulletin No.: 18-NA-355
Chevrolet/
GMC/
Cadillac
Chevrolet/
GMC
Silverado/
Sierra/
Yukon
Denali/
Denali XL/
Escalade/
ESV
Colorado/
Canyon
March, 2019
Page 3
8
CYL. NA
L86
M5U
8
V8
1050-1500
45-55
(72-88)
200375
26
6
CYL. NA
LGZ
M5T
8
V6
1100–1500
42–55
(67-88)
150–
250
25
To confirm TCC Shudder, the vibration concern must be
created in normal operation (Mode A) of the test. If the
concern is gone with the torque converter clutch
disabled (Mode B, TCC Open) and is gone with torque
converter clutch enabled (Mode C, TCC Locked), then
the vibration root cause is TCC Shudder, and the fluid
flush procedure corrective action described below
should be performed.
If the concern is not present in Mode A, then the
vibration concern is NOT TCC shudder.
If the concern is still present with the torque converter
clutch disabled (Mode B) or with the torque converter
clutch enabled (Mode C, TCC slip speed at zero), then
the vibration root cause is NOT TCC Shudder.
Vibrations not identified as TCC Shudder should be
further investigated using the Vehicle Vibration
Diagnosis in SI as a starting point.
Picoscope Test
The PicoScope (CH-51450) essential tool and NVH
software or GDS must be used to confirm TCC
Shudder, Engine, Tire, or Driveline component related
conditions.
To confirm TCC Shudder, record the PicoScope data
while driving in 8th gear in the application specific
condition above. Minimize extraneous vibration input by
testing on a smooth road and correct any other known
vehicle vibration issues (tires, brakes, etc.) before
conducting test. If TCC Shudder is present, a vibration
peak will appear (highlighted by arrow below) within
+/-2 Hz of the frequency listed in the table above. TCC
Shudder vibration frequency is stationary in 8th gear. If
the vibration frequency follows vehicle speed or engine
speed, then it is NOT TCC Shudder.
4629472
In the above illustration, frequency and default view
have been selected.
Important: Obtain a single page screen print from
GDS or PICO Scope that shows the TCC shudder
event. This screen print must be attached to the Repair
Order hard copy for reference. A screen print can be
completed by pressing the Print Screen button on your
laptop computer or by using a program or application
such as Snipping Tool.
Examples of acceptable screen print:
• GDS2 Session showing TCC slip
• GDS2 Special Functions showing TCC Locked
Slip Speed
• PICO Scope screen print showing TCC shudder
(vibration frequency) in the graphic above.
Page 4
March, 2019
Bulletin No.: 18-NA-355
Special Tools
DT-52263 Transmission Fluid Exchange Kit:
• DT-52263-1 Block Assembly (includes fluid drain
hose, spring clamp)
• DT-52263-2 Cooler Line Plug (qty 3) (use with rear
differential cooler)
• DT-52263-3 ½” Cooler Line Flush Adapter for
2019 Silverado and Sierra
• DT-52263-4 3/8” Hose Adapter (6” long with
2 hose clamps)
• DT-52263-5 Radiator Cooler Drain Adapter
1215917
DT-45096 TransFlow Cooler Flush Machine
3763203
•
4733125
DT-51190 Transmission Oil Fill Adapter
DT-45096-31 TransFlow Adapter (one of two pieces
from DT-45096-30)
5181938
•
GE-47716-2 Graduated Bucket
Bulletin No.: 18-NA-355
March, 2019
Service Procedure
Page 5
1. Fill the DT-45096 with 20 quarts of HP fluid.
2. Raise the vehicle on a hoist.
Initial TransFlow Flush Machine Setup
Important: The prepping procedure only needs to be
completed if the DT45096 supply reservoir has
DEXRON VI fluid in it and has not been converted to
use the new blue label Mobil 1 Synthetic LV ATF HP
fluid.
Note: The prepping procedure only needs to be
completed if HP is not in the supply reservoir.
1. Connect the TransFlow adapter DT-45096-31 to
the supply line of the DT-45096 TransFlow
machine.
5182541
3. Install the DT-45096-31 TransFlow adapter (1) to
the DT-51190 fluid fill adapter (2).
5180884
2. Switch the DT-45096 TransFlow to Idle.
3. Connect power leads to the vehicle 12-volt DC
supply.
4. Turn the TransFlow main switch ON.
5. Connect air supply to the DT-45096.
6. Place the TransFlow supply hose with adapter
DT-45096-31 into a waste reservoir using care not
to spill the expelled fluid.
7. Switch the DT-45096 TransFlow to Flow and allow
all the fluid in the supply reservoir to be removed
and placed in the waste reservoir.
8. Switch the control switch back to idle.
Fluid Exchange Procedure - Colorado, Canyon,
Silverado, Sierra, Yukon Denali and Escalade
Models with an Accessible Transmission Oil
Cooler Line Block Assembly
Important: This procedure must be followed as
published. The exchange process is required to obtain
proper level of new blue label Mobil 1 Synthetic LV ATF
HP fluid. Intermixing of other types of transmission fluid
or aftermarket additive packages will result in a low
concentration level of new fluid and will not provide
satisfactory results.
5180563
4. Remove the transmission oil cooler pipe assembly
from the transmission.
5. Install the DT-52263-1 Adapter Block
Assembly (1), reusing the seal from the
transmission oil cooler pipe assembly.
6. Tighten the bolt (2) to 22 Y (16 lb ft).
7. Place the hose (3) in the GE-47716-2 Graduated
Measuring Bucket, utilizing a Spring Clamp to
retain the hose.
Page 6
March, 2019
Bulletin No.: 18-NA-355
13. Shut the engine off immediately.
14. Connect the DT-45096 to the vehicle battery
12 volts and connect shop air to the air connection.
3723844
8. Remove the level set plug (1) from the
transmission.
Important: DO NOT over tighten the DT-51190 as it
can be damaged by excessive torque. DO NOT exceed
9 Y (80 lb in).
9. Install the DT-51190/DT-45096-31 assembly and
hand tighten as shown in the graphic above.
5181027
15. Switch the DT-45096 TransFlow to Flow and add
4 quarts of HP to the transmission.
5181020
3723839
10. Connect the TransFlow fluid feed (supply) line (3)
to the DT-45096-31 adapter (2).
11. Lower the vehicle.
Caution: DO NOT REMOVE MORE THAN 3 QUARTS
OF FLUID AS IT COULD CAUSE FLUID PUMP
CAVITATION AND POSSIBLY DAMAGE THE
TRANSMISSION.
12. Utilizing the graduated bucket, start the engine and
run 30- 45 seconds until 3 quarts of fluid is
expelled.
16. Switch the DT-45096 TransFlow to Idle (Reducing
fluid level in the TransFlow from 20 – 16).
17. Switch the TransFlow DT-45096 to Flow and start
the engine:
17.1. Add a maximum of 4 quarts of HP Fluid to
the transmission, turn the TransFlow switch
to idle once 4 quarts have been added, while
allowing 4 additional quarts of oil to fill the
DT-graduated bucket (Reducing fluid level in
the TransFlow from 16 – 12).
Bulletin No.: 18-NA-355
March, 2019
Note: DO NOT add additional transmission fluid until
the 4 quarts of oil have been removed from the
transmission (Reducing fluid level in the TransFlow
from 12 – 8).
Page 7
24. If equipped, remove the Thermal By-Pass Block
from the cooler pipes on the Escalade, Silverado,
Sierra and Yukon Models.
17.2. Repeat step 17.1.
17.3. Add a maximum of 5 quarts of HP fluid to the
transmission while allowing 5 additional
quarts of oil to fill the DT-graduated bucket
(Reducing fluid level in the TransFlow from
8 – 3).
1762577
25. Install DT-45096-31 adapters (1) to the
transmission oil cooler lines.
26. Connect the DT-45096 TransFlow to the
DT-45096-31 adapters.
5181401
18.
19.
20.
21.
22.
17.4. Shut the engine off once 16 quarts of fluid
have been collected.
17.5. Properly dispose of the expelled
transmission fluid.
Raise the vehicle.
Disconnect the DT-45096 TransFlow feed (supply)
line from DT-45096-31 TransFlow adapter.
Using care, remove DT-45096-31/DT-51190 as an
assembly.
Remove the DT-51190 fluid fill adapter from
DT-45096-31 hose.
Install the level set plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
23. Remove DT-52263-1 Adapter Block Assembly
from the transmission.
5210461
27. Switch the DT-45096 TransFlow to Flush.
28. Flush the vehicle cooler and lines using 2 quarts of
HP fluid.
⇒ Flush 1 quart of fluid through the lines, then
switch the hose connections and flush 1 quart
of fluid in the opposite direction.
Page 8
March, 2019
29. Remove the DT-51190/DT-45096-31 assembly.
30. If equipped, install the Thermal By-Pass Block from
the cooler pipes on the Escalade, Silverado, Sierra
and Yukon Models.
31. Install the transmission oil cooler pipe using a new
cooler block seal.
32. Partially lower the vehicle.
33. Start the engine.
34. Using care, shift the transmission through all
forward ranges and Reverse.
35. Shift the transmission into Park.
36. Perform the Transmission Fluid Level and
Condition Check outlined below in this procedure:
36.1. Get the transmission fluid temperature to the
proper temperature.
36.2. Install the level set plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
The TCC shudder condition should be directional
improved immediately after the fluid exchange
procedure. It may take up to 200 mi (320 km) for the
TCC shudder condition to be eliminated.
Fluid Exchange Procedure - Camaro, CTS and
ATS Not Equipped with a Rear Differential
Cooler
Important: This procedure must be followed as
published. The exchange process is required to obtain
proper level of new blue label Mobile 1 Synthetic LV
ATF HP fluid. Intermixing of other types of transmission
fluid or aftermarket additive packages will result in a low
concentration level of new fluid and will not provide
satisfactory results.
1. Fill the DT-45096 with 20 quarts of HP fluid.
Bulletin No.: 18-NA-355
Bulletin No.: 18-NA-355
March, 2019
Page 9
4194576
Note: The MAF sensor must stay connected so that no
DTCs will set.
2. Separate the engine upper air filter box (1) from the
lower air filter housing to gain access to the upper
transmission oil cooler line.
5181322
5181307
Note: Upper air filter box removed for clarity.
3. Remove the cooler line from the transmission oil
cooler.
4. Install end of the DT-52263-5 Radiator Cooler
Drain Adapter (1) to the DT-52263-1 Block
Assembly.
5. Install the DT-52263-5 Radiator Cooler Drain
Adapter into the upper transmission oil cooler line
port of the transmission oil cooler.
6. Install the DT-45096-31 adapter (3) over the
removed transmission oil cooler line (2) to prevent
any fluid spillage.
Page 10
March, 2019
Bulletin No.: 18-NA-355
7. Place the hose in the GE-47716-2 Graduated
Measuring Bucket, utilizing a Spring Clamp to
retain the hose.
8. Raise the vehicle.
5182541
9. Install the DT-45096-31 adapter (1) to the
DT-51190 fluid fill adapter (2).
3723839
Important: DO NOT overtighten the DT-51190 as it
can be damaged by excessive torque. Do not
exceed 9 Y (80 lb in).
11. Install the DT-51190/DT-45096-31 assembly and
hand tighten.
12. Connect the TransFlow fluid feed (supply) line (3)
to the DT-45096-31 adapter (2).
13. Lower the vehicle.
Caution: DO NOT REMOVE MORE THAN 3 QTS OF
FLUID AS IT COULD CAUSE FLUID PUMP
CAVITATION AND POSSIBLY DAMAGE THE
TRANSMISSION.
14. Utilizing the graduated bucket, start the engine and
run 30-45 seconds until 3 quarts of fluid is
expelled.
15. Shut the engine off immediately.
16. Connect the DT-45096 to the vehicle battery
12 volts and connect shop air to the air connection.
3723844
10. Remove the level set plug (1) from the
transmission oil pan.
5181027
Bulletin No.: 18-NA-355
March, 2019
Page 11
Important: ADDING TOO MUCH FLUID TO THE
TRANSMISSION MAY CAUSE FLUID TO BE
EXPELLED FROM THE VENT SYSTEM. DO NOT
OVERFILL THE TRANSMISSION.
17. Switch the DT-45096 TransFlow to Flow and add
4 quarts of HP to the transmission.
5181020
18. Set the TransFlow switch to idle (Reducing fluid
level in the TransFlow from 20 – 16).
19. Switch the TransFlow DT-45096 to Flow and start
the engine:
19.1. Add a maximum of 4 quarts of HP Fluid to
the transmission, turn the TransFlow switch
to idle once 4 quarts have been added, while
allowing 4 additional quarts of oil to fill the
DT-graduated cylinder (Reducing fluid level
in the TransFlow from 16 – 12).
Note: DO NOT add additional transmission fluid until
the 4 quarts of oil have been removed from the
transmission (Reducing fluid level in the TransFlow
from 12 – 8).
19.2. Repeat step 19.1.
19.3. Add a maximum of 5 quarts of HP Fluid to
the transmission while allowing 5 additional
quarts of oil to fill the DT-graduated bucket
(Reducing fluid level in the TransFlow from
8 – 3).
5181401
20.
21.
22.
23.
24.
25.
26.
27.
19.4. Shut the engine off once 16 quarts of oil
have been collected.
19.5. Properly dispose of the collected
transmission fluid.
Remove the DT-52263-5 Radiator Cooler Drain
Adapter and DT-52263-1 Block Adapter from the
transmission oil cooler.
Remove the DT-45096-31 from the transmission oil
cooler line and install the transmission oil cooler
line using a new retaining clip.
Install the engine upper air filter box back into
position.
Partially raise the vehicle.
Start the engine.
Using care, shift the transmission through all
forward ranges and Reverse.
Shift the transmission into Park.
Perform the Transmission Fluid Level and
Condition Check outlined below in this procedure:
27.1. Get the transmission fluid temperature to the
proper temperature.
27.2. Raise the vehicle and remove the DT-51190/
DT-45096-31 assembly.
27.3. Install the level set plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
Page 12
March, 2019
Bulletin No.: 18-NA-355
The TCC shudder condition should be directional
improved immediately after the fluid exchange
procedure. It may take up to 200 mi (320 km) for the
TCC shudder condition to be eliminated.
Fluid Exchange Procedure - Camaro, CTS and
ATS Equipped with a Rear Differential Cooler
Important: This procedure must be followed as
published. The exchange process is required to obtain
proper level of new blue label Mobile 1 Synthetic LV
ATF HP fluid. Intermixing of other types of transmission
fluid or aftermarket additive packages will result in a low
concentration level of new fluid and will not provide
satisfactory results.
1. Fill the DT-45096 with 20 quarts of HP fluid.
2. Raise the vehicle on a hoist.
5182541
8. Install the DT-45096-31 adapter (1) to the
DT-51190 fluid fill adapter (2).
3723844
9. Remove the level set plug (1) from the
transmission oil pan.
5182245
3. Remove the lower/front transmission oil cooler line
(2) at the rear differential.
4. Install the DT-52263-2 Cooler Line Plug (1) into the
rear differential to prevent fluid loss.
5. Install one end of the DT-52263-4 hose (4) to the
open port of the DT-52263-1 Block Assembly (3).
6. Install the other end of the DT-52263-4 hose to the
transmission oil cooler line.
7. Place the hose in the GE-47716-2 Graduated
Measuring Bucket, utilizing a Spring Clamp to
retain the hose.
Bulletin No.: 18-NA-355
March, 2019
Page 13
16. Switch the TransFlow DT-45096 to Flow and start
the engine:
16.1. Add a maximum of 4 quarts of HP Fluid to
the transmission, turn the TransFlow switch
to idle once 4 quarts have been added, while
allowing 4 additional quarts of oil to fill the
DT-graduated bucket (Reducing fluid level in
the TransFlow from 16 – 12).
Note: DO NOT add additional transmission fluid until
the 4 quarts of oil have been removed from the
transmission (Reducing fluid level in the TransFlow
from 12 – 8).
16.2. Repeat step 16.1.
16.3. Add a maximum of 5 quarts of HP Fluid to
the transmission while allowing 5 additional
quarts of oil to fill the DT-graduated bucket
(Reducing fluid level in the TransFlow from
8 – 3).
3723839
Important: DO NOT over tighten the DT-51190 as it
can be damaged by excessive torque. Do not
exceed 9 Y (80 lb in).
10. Install the DT-51190/DT-45096-31 assembly and
hand tighten.
11. Connect the TransFlow fluid feed (supply) line (3)
to the DT-45096-31 adapter (2).
12. Lower the vehicle.
Caution: DO NOT REMOVE MORE THAN 3 QTS OF
FLUID AS IT COULD CAUSE FLUID PUMP
CAVITATION AND POSSIBLY DAMAGE THE
TRANSMISSION.
13. Utilizing the graduated bucket, start the engine and
run 30-45 seconds until 3 quarts of fluid is
expelled.
14. Shut the engine off immediately.
15. Connect the DT-45096 to the vehicle battery
12 volts and connect shop air to the air connection.
5181401
5181027
16.4. Shut the engine off once 16 quarts of fluid
have been collected.
16.5. Properly dispose of the collected
transmission fluid.
17. Raise the vehicle.
18. Remove the DT-52263-2 Cooler Line Plug from
rear differential and install the transmission oil
cooler line using a new retainer clip.
19. Remove the DT-52263-4 from the transmission oil
cooler line.
Page 14
March, 2019
Bulletin No.: 18-NA-355
20. Install the transmission oil cooler line using a new
retainer clip.
21. Partially lower the vehicle.
22. Using care, shift the transmission through all
forward ranges and Reverse.
22.1. Get the transmission fluid temperature to the
proper temperature.
22.2. Raise the vehicle and remove the DT-51190/
DT-45096-31 assembly.
22.3. Install the level set plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
The TCC shudder condition should be directional
improved immediately after the fluid exchange
procedure. It may take up to 200 mi (320 km) for the
TCC shudder condition to be eliminated.
Fluid Exchange Procedure - Corvette and CT6
Important: The Drain and Fill Procedure Will Need
to be Performed Three Times.
Important: This procedure must be followed as
published. The exchange process is required to obtain
proper level of new blue label Mobil 1 Synthetic LV ATF
HP fluid. Intermixing of other types of transmission fluid
or aftermarket additive packages will result in a low
concentration level of new fluid and will not provide
satisfactory results.
1. Fill the DT-45096 with 24 quarts of HP fluid.
2. Raise the vehicle.
3. Using care, remove the transmission oil pan and
drain the transmission fluid.
4. Install the transmission oil pan.
3723844
6. Remove the level set plug (1) from the
transmission oil pan.
3723839
5182541
5. Install the DT-45096-31 adapter (1) to the
DT-51190 fluid fill adapter (2).
Important: DO NOT over tighten the DT-51190 as it
can be damaged by excessive torque. Do not
exceed 9 Y (80 lb in).
7. Install the DT-51190/DT-45096-31 assembly and
hand tighten.
8. Connect the TransFlow fluid feed (supply) line (3)
to the DT-45096-31 adapter (2).
9. Connect the DT-45096 TransFlow to the vehicle
battery 12 volts and connect shop air to the air
connection.
10. Switch the DT-45096 TransFlow to Flow and fill the
transmission with 8 quarts of transmission fluid.
10.1. Switch the DT-45096 TransFlow to idle.
11. Partially lower the vehicle and run the transmission
through all 8 forward gears, Reverse and Neutral.
Bulletin No.: 18-NA-355
March, 2019
12. Repeat steps 2-4 and 9-10 for 2nd drain and fill.
13. Repeat step 2-3, clean the transmission oil pan
and magnet, repeat step 4 and step 10-11.
14. Perform the Transmission Fluid Level and
Condition Check outlined below in this procedure:
14.1. Get the transmission fluid temperature to the
proper temperature.
14.2. Raise the vehicle and remove the DT-51190/
DT-45096-31 assembly.
14.3. Install the level set plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
The TCC shudder condition should be directional
improved immediately after the fluid exchange
procedure. It may take up to 200 mi (320 km) for the
TCC shudder condition to be eliminated.
Transmission Fluid Level and Condition
Check
This procedure checks both the transmission fluid level,
as well as the condition of the fluid itself. Because the
transmission on this vehicle is not equipped with a fill
tube and dipstick, a tube in the bottom pan is used to
set the fluid level.
Warning: The transmission fluid level must be
checked when the transmission fluid temperature
(TFT) is between 35–45°C (95–113°F). If the TFT is
not within this range, either idle or brake torque the
vehicle to raise the fluid temperature, or shut off the
vehicle to allow the fluid to cool as required. Setting
the fluid level with a TFT outside this range will
result in either an under or over-filled transmission.
TFT>45°C=under-filled, TFT<35°C=over-filled. An
under-filled transmission will cause premature
component wear or damage. An over-filled
transmission will cause fluid to discharge out the
vent tube, possibly causing a fire that may result in
serious bodily injury or severe vehicle damage,
fluid foaming, or pump cavitation.
Note: Silverado, Sierra, Yukon and Escalade Models
equipped with a thermal bypass valve, the transmission
fluid level should be checked only after the TFT has
reached or exceeded an operating temperature of 90°C
(194°F). Once the TFT has reached or exceeded 90°C
(194°F), then turn OFF the vehicle and allow the TFT to
cool back down to 35-45°C (95-113°F) before checking
the fluid level as required. Reaching or exceeding an
operating temperature of 90°C (194°F) opens the
bypass valve and allows the cooler to fill up with fluid,
which will result in a more accurate fluid level check.
1. Observe the TFT using the driver information
center (DIC) or a scan tool.
2. Start and idle the engine.
3. Depress the brake pedal and move the shift lever
through each gear range.
3.1. Pause for at least 3 seconds in each range.
3.2. Move the shift lever back to PARK.
3.3. Ensure the engine RPM is low
(500–800 RPM).
Page 15
4. Allow the engine to idle for a minimum time of
1 minute.
Caution: THE ENGINE MUST BE RUNNING when the
trans oil level check plug is removed or excessive fluid
loss will occur, resulting in an under-filled condition. An
under-filled transmission will cause premature
component wear or damage.
5. Raise the vehicle on a hoist.
⇒ The vehicle must be level, with the engine
running and the shift lever in the PARK range.
Note: Continue to monitor the TFT. If the TFT is not
within the specified values, reinstall the trans oil level
check plug and repeat the previous steps.
6. Remove the transmission oil level check plug (1)
from the transmission fluid pan.
7. Allow any fluid to drain.
• If the fluid is flowing as a steady stream, wait
until the fluid begins to drip.
• If no fluid comes out, add fluid until fluid drips
out. Refer to Transmission Fluid Fill Procedure
in SI.
8. Reinstall the transmission oil level check plug.
Tighten
Tighten the plug to 9 Y (80 lb in).
9. Inspect for external leaks. Refer to Fluid Leak
Diagnosis in SI.
Parts Information
Note: Only select the parts that coincide with the repair
performed.
Causal
Part
Description
X
Mobil 1 Synthetic
LV ATF HP
(Available only
through Local GM
Oil Distributors)
N/A
Part
Number
Qty
19417577
(US - 1
quart)
19418066
(Canada 0.946L/1 qt)
20
Note: Fluid
production
will start in
drums and
will switch to
quarts.
Drums will
not be
available
long term.
24 (CT6,
Corvette)
1
Drum 55
gallon
19417904
(US)
N/A
RETAINER,
TRANS FLUID
CLR PIPE FTG
24205103
2
N/A
SEAL, TRANS
FLUID CLR PIPE
23135703
1
Page 16
March, 2019
Bulletin No.: 18-NA-355
Warranty Information
For vehicles repaired under the Powertrain coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor
Operation
Description
Labor Time
8480818*
Diagnostic Testing and Fluid
Exchange
1.4 hrs
Add
CT6 AWD Triple Drain
and Fill
1.0 hr
Add
CT6 RWD Triple Drain
and Fill
1.6 hrs
Add
Corvette RWD Triple Drain
and Fill
1.6 hrs
Add
DT-45096 Prep (Not
required unless the fluid is
not Mobil 1 Synthetic LV
ATF HP)
0.1 hr
*This is a unique Labor Operation for Bulletin use only.
Version
2
Modified
Released January 17, 2019
March 01, 2019 – Added Canada, Middle East Operations, Mexico and Export Region
reference to Attention statement, added Canada and Middle East Operations to Involved
Region or Country, added printing information to the Important statement under
PicoScope Test section and added fluid part number for Canada, a Note and two
additional part numbers in the Parts Information 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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