93 4runner OD

I have a 93 4runner that I purchased from a little old lady that could no longer drive. The maintenance history is not all there just like the old ladies mind. So just as a precaution I did a major tune up on it. Anyways, the 4runner has a problem shifting into OD since day one of my posession. It started out needing to warm up, approx 7-10 miles then it would shift up. After it was warmed up it would periodically shift back down, especially noted when driving down steep colorado mountain passes. I was given some advise from a friend that maybe if I got my tranny fluid and filter replaced it would eleviate the problem. Well obviously it hasnt, thats why I’m here. Now it wont even shift after its warmed up. I’ve check forums and found everything from clogged temperature sensors and castings to a bad overdrive solenoid that might be on the outside of the tranny. Does anyone have any suggestions? Thanks, Wes

Transmission fluid changes are great for extending a transmission's life, but does almost nothing to fix a problem caused by not changing the fluid more often.  

 Yea, it seems most car makers are no longer listing transmission fluid changes a part of the regular maintenance schedule, but you should make it part of yours.

 I would suggest having a local [b]independent[/b] shop check it out.  Good Luck

Good Luck

If you have not done it yet change the thermostat. On some vehicles of the 90’s OD was blocked when the PCM determined that the engine was still warming up. So if the thermostat is openning a little early or stuck open, the PCM will wait forever for the engine to warm up.

If this is not the problem, check the Coolant Temperature Sensor. If this is out of calibration the PCM will again be waiting for the correct perceived temperature before it will allow OD.

Hope this helps.