I have a 1996 Toyota T-100, ext cab, 4X4, automatic with 40,000 miles. My truck seems like it will not shift into overdrive quick enough when getting up to speed, unless I almost completely take my foot off of the gas pedal. Also when I am in overdrive and want to gain a little speed it automaticly downshifts to the torque converter. I would think that you could give it some kind of gas without it switching to the torque converter. Keep in mind all of this was tested on flat roads. I have a Nissan Xterra 4X4 auto and I can actually give it gas when it is in overdrive without it downshifting. Is there any kind of adjustment with the gas pedal or trans. Any help will be greatly appreciated. Thanks!

I also have a '96 T100 auto. Are you sure you are not confusing overdrive with torque converter lockup? Next time you feel it drop down, try pushing the 'O/D off' button on the end of the stem shifter. If it revs up then you WERE in OD. I had the same issue when I lived near the mountains back East, up a steep hill at 70 mph it would drop down (rev up), but if I hit the OD 'off' button it revved up again. I interpreted that as first being in OD with the torque converter unlocked, then switching off OD. I believe that the torque converter will only lockup during true steady state cruise with no throttle. Addd gas by pedal or cruise control and expect the TC to unlock fairly quickly. I am not a trans expert, so others may feel free to correct my diagnosis!

Well I guess I am experiencing torque converter lock-up. My concern is that it does not seem like my truck shifts into overdrive until I reach 55 to 60 mph, or if I completely let my foot off of the gas and then it shifts to overdrive. If I am not mistaken when the torque converter is locked, it generates more heat in the transmission from it spinning, causing the fluid to heat up and break down. Any input or info would be great. Thanks!

From what my mechanic has told me overdrive does not kick in until 45 MPH and once you have stopped accelerating. As soon as you accelerate or encounter resistance such as a hill or drop below 45 MPH overdrive kicks out for a normal vehicle and that Toyota and a few other 4x4 makers set up there 4x4Æs at 55 MPH and make the overdrive kick out with even the slightest hill or acceleration.

Thanks for the info. I also have a Nissan Xterra and the overdrive on that transmission shifts into overdrive pretty quick even when the accelorator is pushed. What it boils down to is that I can't expect the 2 trucks to shift the same. When going from one truck to the next and noticing they shift totally different, you start to think something is wrong with one of them.