NHTSA ID Number: 10161883
Manufacturer Communication Number: 18NA378
Summary
This technical bulletin provides a procedure to replace the fluid cooler exchanger and the torque converter or transmission and torque converter, depending on if the exchanger leaked into the transmission fluid.
1 Affected Product
Vehicle
CADILLAC | XT4 | 2019 |
Parts
| EXCHANGER, A/TRNS FLUID CLG | 24290617 | 1 |
| TRANSAXLE, AUTO (FWD) | 24274847 | 1 |
| TRANSAXLE, AUTO (AWD) | 24293570 | 1 |
| RING, FRT WHL DRV INTER SHF RET | 90121202 | 2 |
| WASHER, FRT WHL DRV SHF | 11611965 | 2 |
| NUT, FRT WHL DRV SHF (M27 X 2 X 6H) | 11612295 | 2 |
| BOLT, FRT STAB SHF INSL CLA | 11547610 | 4 |
| SEAL, TRANS FLUID CLR PIPE (SLIMLINE WASHER 3/8″) | 25874797
GM Genuine Parts 25874797 Automatic Transmission Fluid Cooler Line Fitting Seal
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API | 2 |
| BOLT, TRANS MT TRANS SI (M12 X 1.75 X 61) | 11547918
GM Genuine Parts 11547918 Multi-Purpose Bolt
Last update on 2026-06-19 / Affiliate links / Images from Amazon Product Advertising API | 4 |
| BOLT, TRANS RR MT BRKT | 11611642 | 2 |
| BOLT, HFH, M10X1.5X75 (TRANS FRT MT) | 11588747
Compressor Bolt
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API | 2 |
| BOLT, HFH, M10X1.5X55, 25.7 THD, 22.3 OD, 10.9 STL, GMW3359 (TRANS FRT MT) | 11588743
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API | 2 |
| SEAL, PROP SHF TO DIFF CARR INTERFACE | 23321677 | 1 |
| RETAINER, PROP SHF TO DIFF CARR INTERFACE | 23432713 | 1 |
| SEAL, PWR TRFER U PROP SHF | 23206807
GM Genuine Parts 23206807 Drive Shaft Seal
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API | 1 |
| RETAINER, PWR TRFER U PROP SHF | 23206808 | 1 |
| GASKET, EXH SYS INTER | 22816982 | 2 |
| SEAL, OIL LVL IND TUBE | 12670252 | 1 |
| FLUID, A/TRANS (DEXRON VI) (1 QT/0.946 LITRES) | Refer to EPC | Refer to EPC |
SEOCONTENT-START
Bulletin No.: 18-NA-378
Date: May, 2019
Service Bulletin
TECHNICAL
Subject: Surge, Chuggle, Fishbite, Shudder Feel During Driving Maneuvers
| Brand: | Model: | Model Year: | VIN: | Engine: | Transmission: | |||
| from | to | from | to | |||||
| Cadillac |
XT4 | 2019 | 2019 | 2.0L (LSY) | 9T50 Automatic (M3H) | |||
| Involved Region or Country | North America, Middle East, Israel | ||||||||
| Condition | Some customers may comment on one or more of the following conditions:
• Surge • Chuggle • Fishbite • Shudder |
||||||||
| Cause | This condition may be caused by fluid contamination from the stack plate heat exchanger. | ||||||||
| Correction | Perform a transmission fluid level and condition check. Refer to Transmission Fluid Level and Condition Check in SI.
1. Order a glycol test kit from the Warranty Parts Center (WPC) using the attached form. 2. Perform a glycol test. • If no glycol contamination is found (no color change), drain and refill the transmission using DEXRON VI. Refer to Transmission Fluid Drain and Fill in SI and further work is needed. • If the glycol level is 50 ppm or above: Important: It may be necessary to drive a minimum of 321 km (200 mi) if slight shudder remains after the repair. 1. Replace the transmission. Refer to Transmission Replacement in SI. 2. Refer to PIP5645 for transmission part restriction information. 3. Replace the transmission fluid cooling exchanger. Refer to Automatic Transmission Fluid Cooling Exchanger Replacement in SI. |
||||||||
Parts Information
Note: Only select the parts that coincide with the repair performed.
| Causal Part | Description | Part Number | Qty |
| X | EXCHANGER, A/TRNS FLUID CLG | 24290617 | 1 |
| N/A | TRANSAXLE, AUTO (FWD) | 24274847 | 1 |
| N/A | TRANSAXLE, AUTO (AWD) | 24293570 | 1 |
| N/A | RING, FRT WHL DRV INTER SHF RET | 90121202 | 2 |
| N/A | WASHER, FRT WHL DRV SHF | 11611965 |
2 |
| N/A | NUT, FRT WHL DRV SHF (M27 X 2 X 6H) | 11612295 |
2 |
| N/A | BOLT, FRT STAB SHF INSL CLA | 11547610 | 4 |
| N/A | SEAL, TRANS FLUID CLR PIPE (SLIMLINE WASHER 3/8″) | 25874797
GM Genuine Parts 25874797 Automatic Transmission Fluid Cooler Line Fitting Seal
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API |
2 |
| N/A | BOLT, TRANS MT TRANS SI (M12 X 1.75 X 61) | 11547918
GM Genuine Parts 11547918 Multi-Purpose Bolt
Last update on 2026-06-19 / Affiliate links / Images from Amazon Product Advertising API |
4 |
| N/A | BOLT, TRANS RR MT BRKT | 11611642 | 2 |
| N/A | BOLT, HFH, M10X1.5X75 (TRANS FRT MT) | 11588747
Compressor Bolt
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API |
2 |
| N/A | BOLT, HFH, M10X1.5X55, 25.7 THD, 22.3 OD, 10.9 STL, GMW3359 (TRANS FRT MT) | 11588743
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API |
2 |
| N/A | SEAL, PROP SHF TO DIFF CARR INTERFACE | 23321677 |
1 |
| N/A | RETAINER, PROP SHF TO DIFF CARR INTERFACE | 23432713 |
1 |
| N/A | SEAL, PWR TRFER U PROP SHF | 23206807
GM Genuine Parts 23206807 Drive Shaft Seal
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API |
1 |
| N/A | RETAINER, PWR TRFER U PROP SHF | 23206808 | 1 |
| N/A | GASKET, EXH SYS INTER | 22816982 |
2 |
| N/A | SEAL, OIL LVL IND TUBE | 12670252 | 1 |
| N/A | FLUID, A/TRANS (DEXRON VI) (1 QT/0.946 LITRES) | Refer to EPC | Refer to EPC |
Warranty Information
Note: Only select the Labor Operation that coincides with the repair performed.
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 |
| 8464670 | Transmission Replacement | Use Published Labor Operation Time |
| 8480808* | Automatic Transmission Fluid Pan Drain and Fill | Use Actual Clock Time |
| Add | Glycol Test | 0.3 hr |
| *This is a unique Labor Operation for Bulletin use only. | ||
| Version | 4 |
| Modified | Released December 17, 2018
January 22, 2019 – Added the AWD Torque Converter part number to the Parts Information section. February 04, 2019 – Added Warranty Information. May 16, 2019 – Updated the Correction section and Warranty Information and added the WPC Part Request Form. |
IMPORTANT NOTE WHEN PRINTING THIS FORM: If the form prints out on two pages, make certain you fax BOTH pages so that the WPC receives all the needed information. Missing information will delay or prevent the part from being shipped.
| Parts Request Form – Warranty Parts Center |
| Use this form ONLY for U.S. and Canadian Dealers. Export markets and Mexico Dealers must contact their regional Technical Assistance Center for assistance. To: Warranty Parts Center e-mail: [email protected] or WPC Fax: 248-371-0192
Attn: WPC Customer Assistance Part Being Requested: Glycol test (P/N WPC #835) Dealer BAC (U.S.) /Dealer Code (Canada)/Dealer Number (Mexico): Dealer Name: Dealer Address: Dealer Contact Person: Dealer Phone Number: Repair Order Number: Vehicle Model Year: Vehicle VIN: Important: If you do not receive the part within 2 business days after e-mailing or faxing your part request to the Warranty Parts Center, please call WPC Customer Assistance at 248-371-9901/9902. |
IMPORTANT NOTE WHEN PRINTING THIS FORM: If the form prints out on two pages, make certain you fax BOTH pages so that the WPC receives all the needed information. Missing information will delay or prevent the part from being shipped.
SEOCONTENT-END
Bulletin No.: 18-NA-378
Date: May, 2019
To View or Download this Document Click Here
SEOCONTENT-START
Bulletin No.: 18-NA-378
Date: February, 2019
To View or Download this Document Click Here
SEOCONTENT-START
- Backward compatible with previous Dexron automatic transmission fluids and can be used as a much-improved replacement for older vehicles/transmissions originally using previous Dexron fluids
- Improved performance over previous Dexron fluids in: friction durability, viscosity stability, aeration and foam control, and oxidation resistance
- Potential to enable improved fuel economy and longer transmission life
- Provides for extended drain intervals. Provides consistent shift performance, even in extreme conditions.
- Formulated with full-synthetic base stocks and advanced additive technology to meet the challenging demands of automatic transmissions
- Enhanced anti-shudder protection for smooth shifting and maximum power transfer
- Developed with anti-wear technology to help improve transmission durability
- Engineered with a proprietary blend of base oils and advanced additives to provide better oil flow at low temperatures and greater film protection at higher temperatures
- For use in 95% of vehicles including most CVTs in operation with US registered light duty applications
- High performance conditioning agents prolong seal elasticity to prevent leaks
- Improved durability & transmission life with anti-wear technology to avoid costly repairs
- Enhanced high & low temp performance supports transmission fluid in all weather situations
- Full synthetic formula with advanced additives protects against transmission breakdown better than conventional fluids
- Formulated with full-synthetic base stocks and advanced additive technology to meet the challenging demands of automatic transmissions
- Enhanced anti-shudder protection for smooth shifting and maximum power transfer
- Developed with anti-wear technology to help improve transmission durability
- Engineered with a proprietary blend of base oils and advanced additives to provide better oil flow at low temperatures and greater film protection at higher temperatures
- Backward compatible with previous DEXRON automatic transmission fluids and can be used as a much-improved replacement for older vehicles/transmissions originally using previous DEXRON fluids
- Improved performance over previous DEXRON fluids in: friction durability, viscosity stability, aeration and foam control, and oxidation resistance.
- Designed for anti-wear protection and shear stability
- Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
- ACDelco GM Original Equipment parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
Last update on 2026-06-13 / Affiliate links / Images from Amazon Product Advertising API
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