terri73

My transmission doesn't seem to be working right in overdrive...when going 55 mph the rpms are reaching 3000...any ideas?

Also does anyone know how to replace the glass out of the sunroof?

Steveh29

What year/model 4Runner? First thing I'd do is to verify it's shifting through all the gears. You can count as you feel it shift. If it's sticking in 2nd or 3rd or not going into overdrive it could behave like this. I've had an experience where the overdrive solenoid broke and would not activate the overdrive. I've also had one where the overdrive solenoid was so crudded up it couldn't activate the overdrive. I've also had vacuum leaks on older transmissions that caused erratic shifting or failed upshifts.

Final thought: My friend's second generation had this problem. The converter was not locking up. It would rev high and the transmission light would come on as it cooked the fluid. Eventually trashed the tranny. Check your fluid to make sure it's not burning up.

Hope this helps.

terri73

Hi, thanks for the reply, it's a 1991 4x4 automatic v6..replaced the tranny with another used one and it does the same exact thing the last one did. It will go into overdrive but not all the time, and like i said the rpms are running high when it does this.

Steveh29

If this tranny is doing the exact same thing as the old one, and the problem is intermittent, I'd say there's a problem with the equipment telling the overdrive to engage. This could be a faulty sensor, bad wiring or plugs going to the transmission or the computer goofing up. First thing I would do is to see if the transmission is throwing a code. I believe there are some codes designated to the transmission. I'll check my manual tonight. I've got a 5 speed or I'd be more up on this.

Next, check all the wires going to the transmission are not frayed, cracked or damaged. This includes checking the plug ends to make sure they're clean and not corroded. Wires often break at the point where it enters the plug.

Finally I'd check what sensors the transmission uses to know when to shift to overdrive. Maybe there's an RPM sensor, or throttle body sensor used. I do know there's a tempature sensor that will prevent upshifting in the transmission until the engine reaches operating tempature. If this sensor is reading cold intermittently that could cause the problem. I'll poke through my manual tonight.

Steveh29

Sorry for the late reply. The computer does indeed reference a temp sensor to verify it's OK to go into overdrive. If the engine is cold - or the computer thinks it's cold it will not allow the upshift. I will send you off line the procedure for checking the computer for transmission codes. This should help with a diagnosis.

Dryheat

Also check the throttle valve cable for correct adjustment. OD will kick in at speeds as low as 45 mph. With the transmission warmed up you should be able to let up on the throttle just a bit to get it into OD once you are above 45 mph with the power mode ECT button off. I think I saw something in the service manuals that indicate the speed ranges and throttle conditions that it should shift to OD.

ctcost

Shift solenoids. Yup...Mine was doing the same thing...I had a rebuild done and they tried to get away w/out replacing them...It was the same probby before and after a $3000 rebuild. Did the research and told em to change em out. They can be very hard to diagnose as the probby is REALLY intermittent.

Steveh29

I've scanned the transmission diagnosis pages from my Toyota manual. They're too large to post. I'll email them to you offline.

ctcost

yeah make sure the mech goes by the codes and not just drive tests.

ErikB

Yes, and simply replacing the thermostat will usually fix the problem. This is a fairly common problem on the 3.0's.

ctcost

Funny how missing one little line can lead to wrong output...My bad!


Yup what they said

toyotaoffroad91

CTCOST...when your solenoids went bad did they throw codes??

Munkymag

Sorry had too bring this back. I just changed out my Solenoids in my auto tranny in my 87 4runner. Now that i got in those new parts its now not wanting too go into gear? Any one have light on this? Is it cause i don't have full tranny oil lvl's? It was working before i took the old ones out.

Munkymag

thanks guys. I just put in a used trans from ah 88 v6 4runner. Everything running sweet as of now. The trans that was giving me head aches is now out and pulled apart for parts. The new one in now is running strong and sweet, better then when i frist drove it home. Sweet deal guys, gonna go get stuck sum where 2morrow i hopE