when is transmission slipping not really slipping

[craigatkins]

My 93 v6, 4wd, automatic transmission seems to be slipping. The problem starts when my speedometer starts to jump about irratically and then the tranny seems to slip out of gear, the tach raises but there is no power. I can shift down to first gear and it will go, and I can turn it off and it seems to reset itself for a bit. Could this be caused by some sort of sensor or something other than the transmission slipping?

 

[MikeInNH]

There is no sensor that is going to cause what you described. When in gear and you press on the gas and the rmps go up, but the car doens't move...pretty much means only one thing....Tranny or clutch. Since you have an automatic...it's tranny slip. Not sure if those trannies can be adjusted.

 

[craigatkins]

Toyota tells me that in fact there is a speed sensor on the rear of the transmission that sends two messages, one to the speedometer and one to lock or unlock the torque converter. That when the speedometer stops working it tells the tranny that you have stopped and then sends a second message to the torque converter telling it to unlock and go into neutral. I hope they are right, Toyota charges 275 for the part, Napa is 90.00. I will post once I get it on and see if it makes a difference.