On the 4L80-E Transmission (Diesel and 7.4L gas engine), Transmission fluid may leak through the electrical connector on the side of the transmission, damaging the wire harness and causing the transmission to shift erratically. Our technicians tell us there are updated shift solenoids, an internal transmission harness, and a connector pigtail available to correct this fault.
Transmission Fluid Leak, Erratic Shifting on GMC Vandura 3500
Average mileage: 118,000 (118,000–118,000)
4 people reported this problem
1993 GMC Vandura 3500 118,000 mi, Visitor
Hard to shift