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.Google+
Car Problem Reports
Toyota T100 Automatic Transmission May Not Shift Correctly at High Mileages
Toyota T100 Problem
Drive Trains Affected: 2WD, 4WD
Average Mileage: 137,348 mi (117,000 mi - 149,600 mi)
Doesn't shift from 2nd to 3rd when cold. When engine temp is on the way up to normal, it will shift. A 2 minute warm up usually works. Also shifting onto OD doesn't usually happen until 55 MPH, even when driven for 10 miles or more. Letting off the gas at 50-53 MPH will sometimes allow it to shift but not always.
Visitor, 1997 Toyota T100, 4WD
most the time i break i here a sqeez noise.
Visitor, 1993 Toyota T100
Visitor, 1997 Toyota T100, 2WD, 149,600 mi
Transmission fails to shift properly at the 2-3 shift when cold. Called toyota and they have informned me it is normal. this process is to get the A/T fluid up to temp