A concern that could arise is that the rear wheels may lock up; this will impact about 500000 full-size bodies on frame vehicles, GMC Yukon, and Chevrolet Silverado included. General Motors has launched a recall of its 461,839 diesel vehicles, which includes full-size trucks and SUVs, because a faulty gearbox could cause the back wheels to lock up. This problem is applicable to the 2020-2022 models of the Chevrolet Silverado and GMC Sierra models of 1500, 2500, and 3500. Also, the 2021 Cadillac Escalade, GMC Yukon, Chevy Suburban, and Tahoe are among the vehicles involved in the recall.
The use of a control valve in the gearboxes can be very extreme, which causes shifts to be harsh or even reach a point where a gear shift will force the rear wheels to lock up. A report from a GM engineer in June 2024 elaborated on a case of a 2021 GMC Sierra 2500 pulling a trailer. In the first appraisal, the automaker stated that if there were a lockup, it would not persist long enough to deny anyone control. However, a quantitative analysis of the data collected after controlling for a number of factors gave a rather different picture.
Through mid-September, GM had received 1,888 complaints of lock-ups which might have been caused by this problem, and several reports of cars straying off the road and damaging property. Three reported cases of minor injury incidents, which cannot be attributed directly to crashes, have been associated with the lock-up phenomenon.
Instead of recalling some of its models and re-fixing the faulty valves, General Motors plans to produce software that will detect and prevent hard shifting and excessive wear and tear in the transmission. This software update will theoretically restrict it to the fifth only and bring up the check engine light roughly 10,000 miles before a potentially damaging lock-up problem, so the drivers can address it before it develops further. More so, specific early December will be devised for sending particular alerts to specific car owners after starting to make dealer notifications for an active recall.
Out of the 461,839 cars involved in the problem, an overwhelming majority, or 377,951, are considered pickup truck models. The recall is focused on only 1,502 Escalades but also on 5,182 Yukons and 6,383 Suburbans/Tahoes.
