In the morning when the truck is cold the overdrive does not kick in till it warms all the way up. Is there a sillanoid for the overdirve on the outside of the tranny?

 

overdrive won't engage until the coolant is at operating temperature, or slightly before, and the vehicle is going faster than 35 mph.

 

Yea I kind of figured that.

 

But the thing is I always warm up my trucks, and then after driving 5 miles to the freeway and then running 3 miles on the freeway till the overdrive kicks in. Is there anything like changing a silanode or if I change the tranny filter and oil help?

 

on the 22re motor there is a temperature sending unit for the trans,engine and computer.you might check to see if the trans. sending unit is going bad.

 

Might want to check if you have the right thermostat.

 

My diesel does the same thing but it doesn't go for that long a distance. It locks up at 70*C AFAIK. I have the A343F tranny. Also if you want it to lock up before that there is a mod for the diesels to put in a torque converter lockup switch. I would assume that the gas autos would be somewhat similar. This enables you to lock it up in any gear but 1st and reverse. This would let you force it into OD lockup.

 

Does anyone know how to lock the overdrive like 82yota is talking about?

 

There is no way to by pass it, it is controlled through the temp sensor and the trans computer. Let it warm up and it will shift

 

if you havent changed your tstat. i would do so.

 

Actually, it's really easy to bypass. The OD enable/Disable is controlled by a thermoswitch, which SHOULD enable OD around 55C. I don't have my FSM in front of me, but when it warms up, I believe it goes upen circuit, so you just need to unplug the wire from it to enable the OD.

The other alternative, if I'm completely backwards on the operation of the thermoswitch, is to unplug it, and ground the wire.

 

Odd, my 91 will hit OD within 1/4 mile of the first start in the morning even when it's 40F outside.
Or is this a 4wd only thing?

 

Well guys that was it. After the new T stat put in, the next morning with it 30F the heat went to just below the middle on the gauge and the over drive kicked right in. Thanks for the help guys. And if anyone else has the same problum then this is probliy it. And it cant hurt for only $10 fix.

 

did the 1st gen runners even come in 2wd

 

Nope, they did not.

 

I have one more question, were is the sensor for the overdrive at the coolant? And why can't I just ground or run positive to the sensor, so the OD kick in even if the engine isn't warm?