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
1 person shared problem details
1993 GMC Vandura 3500118,000Visitor
Hard to shift
When I start my truck in the morning it will not shift out of low gear. when it gets to 170 deg...
transmision will shift fine except into drive stays in secound I believe that it is the speed s...
my transmission shift sometime rough and other time it will not get out of second gear.
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