General Motors is expanding an earlier recall of some 2011 model year trucks and SUVs to fix a problem that could cause the vehicles' rear axles to lock.

The recall, originally announced in December, now covers 26,751 Cadillac, Chevrolet and GMC trucks and SUVs. The models affected are: Cadillac Escalade, Escalade ESV, Cadillac EXT, Chevrolet Avalanche, Colorado, Silverado, Suburban, Tahoe; and GMC Canyon, Sierra, Yukon and Yukon XL.

GM said rear-axle cross pins, used to hold the axle in place, weren't properly heat-treated and may not be durable. They can fracture, interfere with the axle and cause it to lock. The driver could then potentially lose control of the vehicle.

GM says owners of the -vehicles are being contacted and urged against driving the trucks until the axle pin is replaced.

The December recall for this same issue covered 1,262 trucks and SUVs. But the company has since discovered that more vehicles were built with the faulty axle pin.