I have recently aquired a 94 4runner with the 3.0 and automatic transmission. The problem that I am experiencing occurs when I am towing my popup camper. The transmission seems to want to jump out of 4th (even on fairly level grade) down to 2nd, then 3rd, back to 2nd, etc. It is just jumping all over the place. The problem does seem to lessen after driving awhile. Unfortunately, the vehicle didn't come with much service history, so I can't tell if the transmission was ever serviced regularly. I went into the deal knowing that it was a buyer beware situation, but I did get it for approx 2k below book. Am I in a situation where I will be back up to book value once I replace the transmission or could it be something else? Any suggestion would be helpful.

Thanks

Try replacing the thermostat. If it is not operating correctly, it can do weird things to the higher gears' shift points.

Would you suggest an aftermarket thermostat or an one from the Toyota dealer? I can't imagine there would be much of a difference.

There is so little price difference, you are better off going with a thermostat of known quality - from Toyota.

Thanks for the quick response. Much appreciated.