SAR

I have the dreaded "won't shift into Overdrive" issue. Here are the particulars:

97 4runner, 3.4L 5ZE 4WD

1. Problem is ambient temperature dependent - it shifts into Overdrive when the outside temperature is over 80 degrees
2. It takes 40 miles on the highway for the transmission to shift into Overdrive - this happens at any outside temperature.
3. Sometimes it will kick in when the cruise control is engaged when the outside temperature is warm (80 degrees +).

Here's what I've done so far (as per the threads on this site):

1. Changed thermostat
2. Changed Coolant Sensor
3. Inspected the bypass hose - no kinks or clogs.

What should I look at next? The transmission shifts perfectly in every other gear.

Thanks in Advance.

SAR

Hello, anyone there?

ninjarunner

We are stumped.. maybe the tranny fluid.. you have it changed anytime recently?? look to see what color it is. if its black. thats a bad thing.

SAR

Thanks for the reply, ninjarunner.

Should have included the fact that the fluid was changed in May in my original post...sorry.

I was driving today on the highway. After 30+ miles at highway speed, I was able to get OD engaged in two ways:

1. Turn off cruise, then turn it back on.
2. Hit the "O/D OFF" button on then off again.

The O/D will work OK after it catches the first time (for example, after stopping at a rest area and getting on the highway again, it shifts into O/D perfectly at 50 miles per hour).

Thanks for any help you can give.

Joe's Toy

Your tranny sounds like it has a memory problem. It just needs a little reminding that it has 4th gear is all.

Do you think it could be something with the linkage? like maybe you need to adjust you shifter down where it "connects" to your tranny?
Will it shift into O/D if you hit a bump at 50+ mph?

kawicowboy

Just a thought, I had a simmiler problem, mine would go into overdrive evreytime over 30, it would only kick down after I floored it or hit the overdrive switch. The problem got fixed after I changed the plugs and wires, Like I said just a thought.
Have you checked the switch on the gear shift.

SAR

Thanks for the replies guys. Checked the linkage and switch...they look OK. Is there a temp sensor on the tranny? I thought that I read somewhere that there was. If anyone knows where it is and if it's difficult to replace...

Thanks.

mt_goat

Sounds like a solenoid problem to me, pretty common for older Toyota auto trannys. See the very end of this article: http://rigs.corequipment.com/Cebby/9...20Transtec.pdf Things as small as lint from a rag can cause problems with shift solenoids. Did this start after a tranny flush?

Here's some good pics of where the solenoids are:
http://members.cox.net/mgriese5/Level10.html

See a FSM for which shift solenoid controls the OD engagement. Here's a 03 Tacoma FSM it may be the same:
http://www.deserted1.com/FSM/

SAR

Thanks Mt. Goat.

As a matter of fact, the tranny did have a flush when I bought my 4runner from a Toyota dealer in May. I'll try looking at the O/D solenoid.

Thanks for your help. Those links are great.

SAR

Thanks to everyone that replied.

For anyone that has this problem in the future, here's what fixed the issue: the cruise control actuator.

It seems that the signal to shift into overdrive goes through the actuator. If the actuator is not sending or receiving voltage properly, the overdrive solenoid will not engage.

This was proven by disconnecting the actuator then driving. The overdrive engaged perfectly every time.

After installing a used actuator (the dealership cost for a new one was $1200! Used: $160) the vehicle is running great.

881stGenRunner

im having very similar problems with my A340H, do yall think my 88 3.0 has this cruise control actuator?

SAR

Don't know, but my guess is that if it has cruise control, there should be an actuator. If you can find it and disconnect it and the tranny goes into overdrive then you had the same symptoms I had.

mt_goat

Interesting, never heard that one before. Good to know.