An internal transmission issue can cause a longer than normal shift from first to second gear, and it can feel harsh. Premature wear of the accumulator seal from scuffing of the accumulator case bore is the cause, and replacing the 1-2 accumulator spring, seal, and piston will correct this concern.
Longer Than Usual Shift from First to Second Gear, Harsh Shift on Ford Mustang GT
Average mileage: 198,000 (198,000–198,000)
Drive Train affected: Automatic Transmission
6 people reported this problem