Two problems related to differential unit have been reported for the 1999 GMC Jimmy. The most recently reported issues are listed below.
: the contact stated while driving 30 mph, there was a thumping noise from underneath the rear of the vehicle, and it was difficult to steer from side to side. The vehicle was inspected by an independent repair shop, who determined the differential unit failed and needed to be replaced. The manufacturer was alerted.
The engine light illuminated several times, because the air pump froze, the right front wheel bearing, fuel pump, and rear differential bearings were replaced.