Problem Description and Possible Solution
At higher mileages, (125,000-150,000) the automatic transmission may not shift correctly. This can be caused by the throttle position sensor being out of adjustment or a shift solenoid needing to be replaced. Typically the transmission does not need to be completely overhauled.
Average mileage: 172,001 (100,000–250,000)
Drive Trains affected: 2WD, 4WD
22 people reported this problem
Sometimes drives ok, shifting late, or not shifting above third. Other times it won't shift beyond first. Added transmission seal repair, and this seemed to help for a week or so. It's being worked on right now and the kickdown cable is locked in position. We shall see ...
Transmission will not downshift when depressing the accelerator on the highway, or when going on a slight incline at a speed higher than 30 miles per hour. I have to manually drop the transmission from D to 2 in order to accelerate when not on the Highway, and I have to disengage overdrive while on the highway. I intend on replacing the shift solenoids and installing a performance kit in the valve body to remedy the problem. If I absolutely need to, I will replace the TPS (throttle positioning sensor) and have it calibrated (although from what I understand it is a simple open circuit, closed circuit switch and not a proportional switch as the ECM, EFI, and control system is somewhat obsolete).
I drive my truck almost everyday and about once a week the automatic transmission will not upshift from 2nd to 3rd and then will sometimes downshift and start "hunting" for a gear, either upshifting then downshifting even though my foot is steady on throttle.