Service Bulletin

Bulletin No.:

18-NA-355

Date:

April, 2020

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.
Note: This procedure should only be completed once
per vehicle. Any vehicle that returns with suspect
shudder should be diagnosed utilizing published
diagnostics, GDS, PICO Scope or other diagnostic
tools. Sometimes shudder is not caused by the torque
converter clutch (TCC). In some instances, shudder is
fish bite, chuggle, surge or vibration.
Model Year:
Brand:

Model:
ATS
CTS

Cadillac

CT6

from

to

2016

2019

2016

2018

from

to

Engine:
(2.0L, 2.5L, 3.0L,
3.6L, 5.3L, 6.2L)

Transmission:
(8L45, 8L90
Automatic)

Feb.
1, 2019

LCV, LGX, LTG,
LT4, LF4

M5N, M5T, M5U

LGX, LGW, LTG

M5N, M5X

L86

M5U

EOP

Escalade
Models

2015

2017

Camaro

2016

2019

Feb.
1, 2019

LGX, LTG, LT1

M5T, M5U

Colorado

2017

2019

March
1, 2019

LGZ

M5T

Chevrolet

GMC

Date Breakpoint:

SOP
Corvette

2015

2019

Feb.
1, 2019

LT1, LT4

M5U

Silverado
Models

2015

2018

EOP

L83, L86, L8B

M5U, M5X

Canyon

2017

2019

March
1, 2019

LGZ

M5T

Sierra
Models

2015

2018

L83, L86, L8B

M5U, M5X

Yukon
Models

2015

L86

M5U

EOP
2017

Involved Region or Country

United States, Canada, Middle East Operations (MEO)

Condition

Some customers may comment that their vehicle is experiencing 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.

⇒ The condition may be described as if they are driving over rumble strips or a
concrete road surface with rough expansion joints.
Cause

Copyright 2020 General Motors LLC. All Rights Reserved.

This condition may be due to Torque Converter Clutch (TCC) Shudder.

Page 2

April, 2020

Bulletin No.: 18-NA-355

Note: This procedure should only be completed once per vehicle. Any vehicle that
returns with suspect shudder should be diagnosed utilizing published diagnostics, GDS,
PICO Scope or other diagnostic tools. Sometimes shudder is not caused by the torque
converter clutch (TCC). In some instances, shudder is fish bite, chuggle, surge or
vibration.
Correction

Vehicles that are presented with TCC shudder should have the appropriate fluid
exchange procedure completed. Diagnosis beyond the customer compliant is not
required if vehicle was built prior to production dates indicated above.
For vehicles built after the production dates listed above.

⇒

If a customer presents a vehicle with a similar complaint, follow normal SI
diagnostics. These vehicles are already equipped with the latest HP fluid.

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 and Camaro V8 non 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

3763203

•

DT-51190 Transmission Oil Fill Adapter
5181938

•

GE-47716-2 Graduated Bucket

1215917

•

DT-45096 TransFlow Cooler Flush Machine

Bulletin No.: 18-NA-355

April, 2020

4733125

•

DT-45096-31 TransFlow Adapter (one of two
pieces from DT-45096-30)

Page 3

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

Service Procedure
Initial TransFlow Flush Machine Setup
Important: The prepping procedure only needs to be
completed if the DT-45096 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 fluid is not in the supply reservoir.
1. Connect the TransFlow adapter DT-45096-31 to
the supply line of the DT-45096 TransFlow
machine.

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 20 quarts of HP fluid.
2. Raise the vehicle on a hoist.

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.

Page 4

April, 2020

Bulletin No.: 18-NA-355

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.
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.

3723839

Bulletin No.: 18-NA-355

April, 2020

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.
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.

Page 5

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).
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).
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).

5181027

15. Switch the DT-45096 TransFlow to Flow and add 4
quarts of HP to the transmission.

5181401

18.
19.
5181020

16. Switch the DT-45096 TransFlow to Idle (Reducing
fluid level in the TransFlow from 20–16).

20.
21.

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.

Page 6

April, 2020

22. 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.
24. If equipped, remove the Thermal By-Pass Block
from the cooler pipes on the Escalade, Silverado,
Sierra and Yukon Models.

Bulletin No.: 18-NA-355

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.
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

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.

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 320 km (200 mi) for the
TCC shudder condition to be eliminated. It is not a
requirement for the dealer to drive the vehicle 320 km
(200 mi). The customer should be advised that the full
effect will take up to 320 km (200 mi) and a minimum of
two cold to operating temperature drive cycles.

Fluid Exchange Procedure - Camaro (Except
Camaro V8-See Procedure below for Camaro
V8), 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 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 20 quarts of HP fluid.

5210461

27. Switch the DT-45096 TransFlow to Flush.

Bulletin No.: 18-NA-355

April, 2020

Page 7

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