Tag Archives: Wheels Lock Up

GM Wheel Lock-Up From Transmission Control Valve Defect

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General Motors (GM) has announced a safety defect affecting the transmission control valve in certain Chevrolet, GMC, and Cadillac vehicles equipped with diesel engines. The issue involves excess wear on the transmission control valve, which could lead to a gradual loss of pressure. This defect has the potential to cause harsh shifting, and in rare cases, a momentary lock-up of the rear wheels.

The Affected Vehicle Models Are:

2021 Cadillac Escalade
2021 Cadillac Escalade ESV
2020-2022 Chevrolet Silverado 1500
2020-2022 Chevrolet Silverado 2500
2020-2022 Chevrolet Silverado 3500
2021 Chevrolet Suburban
2021 Chevrolet Tahoe
2020-2022 GMC Sierra 1500
2020-2022 GMC Sierra 2500
2020-2022 GMC Sierra 3500
2021 GMC Yukon
2021 GMC Yukon XL

GM first became aware of this issue in June 2024 through the company’s Speak Up for Safety (SUFS) program, after a customer claimed that the rear wheels of a 2021 GMC Sierra 2500 HD pickup allegedly locked up while towing a trailer. The incident caused property damage to both the vehicle and the trailer. This report prompted GM to open a new investigation.

Previously, GM had already investigated the condition, finding that excessive wear in the transmission control valve could cause harsh downshifting and, in some cases, a momentary lock-up of the rear wheels. Earlier tests and analyses suggested that the lock-up was unlikely to lead to loss of vehicle control, and no accidents or injuries were reported at the time.

In July, the National Highway Traffic Safety Administration (NHTSA) notified GM that its Vehicle Owner Questionnaire (VOQ) monitoring process had flagged additional reports that could be related to this issue. GM’s investigators conducted an extensive analysis of these reports and reviewed comprehensive field data, identifying 1,888 field reports alleging a potential lock-up condition. Further examination revealed eleven specific incidents where the vehicles veered off the road, causing minor property damage. There were also three minor injuries reported, although none were linked to a collision.

Based on these findings, GM’s Safety Field Action Decision Authority (SFADA) decided in October to initiate a safety recall.

To address the defect, GM dealers will install updated transmission control module software. This software will monitor valve performance and detect signs of excess wear approximately 10,000 miles before a wheel lock-up condition could occur. If excess wear is detected, the software will limit the transmission to fifth gear, effectively preventing a wheel lock-up scenario, which typically happens during a downshift from eighth gear. Additionally, the vehicle’s instrument panel will display a service engine light and a reduced propulsion warning message to alert the driver. GM’s number for this recall is N242454440 and the NHTSA campaign number is 24V-797.

Front Wheels May Lock Up in 2023 Ford Trucks and SUVs

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Ford is reaching out to the owners of certain 2023 Ford trucks and SUVs regarding a power-train issue that could lead to a loss of 4-wheel drive. The front wheels could also lock up as a result of the defect. This problem has been discovered in the 2023 model year Ford F-150 4×4, as well as the Ford Expedition 4×4 and Lincoln Navigator 4×4 vehicles.

The problem was first detected in January 2023 during the loading process, when reports of front axle pinion fractures on three F-150 4×4 vehicles were received by Ford’s critical concern review group (CCRG). An investigation into the issue found that the same pinions were installed on the Expedition and Navigator 4×4 vehicles.

Further investigation showed that the fractured pinions did not undergo the required heat treatment process at Ford’s axle manufacturing plant. This heat treatment process is crucial to reduce the hardness and brittleness of the pinion stem threads. The problem was limited to pinions in 3.73:1 gear ratio axles, and a team was dispatched to conduct eddy current hardness checks of all available stock at affected assembly plants. The CCRG investigative team also reviewed plant process records to determine the build population of suspect dates.

The pinion can break at any time in 4×4 applications, but it is expected to happen primarily while in reverse as the pinion is subject to higher loads. The driver may hear a loud noise when the pinion breaks or when the drive shaft and flange hit the frame cross member and stability bar after the pinion fractures.

Ford will replace the front axle pinion gear set, and if there is a broken front axle pinion, the entire axle assembly will be replaced. Ford’s recall number is 23S07, and the NHTSA campaign number is 23V-128.

If you own a 2023 Ford Expedition, F-150, or Navigator, it is important to be aware of this recall and take appropriate action. This is a safety-related issue that should be addressed to avoid any potential safety hazards while driving.