ramrugby09

Does any body know where the over drive relay is on a 1986 4runner with an auto tranny? My tranny won't down shift from over drive. Thanks

eric-the-red

I don't know about the older vehicles but on the newer trannies overdrive is controlled by the computer, there isn't a relay. And from what I've read most of the shifting problems on Toyota trannies are from sticking or dead solenoids. Does it shift OK if you move the lever manually.

ramrugby09

it will not come out of over drive when I hit the O/D button

eric-the-red

I just looked through the FSM I have and there is an overdrive relay in the trucks, shown on the left side of the dash. According to the manual the 4Runners don't have one My manual is for a 1995 so for yours it may be different. It covers A340E, A340F and A340H trannies, if you have one of those it might help.. If you want a copy send me an email address.

ramrugby09

Does anyone know where I can get a good deal online for some solinoids for a A340H? Also do I need to remove the tranny to do it?

regularguy412

I don't have a source for the solenoids, but I believe the solenoid replacement operation can be done with the tranny in the vehicle. Here's a link to the 93 FSM. Look in the tranny section for the A340H and go from there.

http://personal.utulsa.edu/~nathan-buchanan/93fsm/

Mike in AR

ramrugby09

Thanks...I'll figure this out eventually

ctcost

Check ebay. There was a guy rebuilding them if you can wait. Otherwise they are expensive...My quote was $185.50 a piece and, you might as well do both...I got mine free with a tranny remanufacture (thanks to links in this forum, I found out it was part of the tranny rebuild procedure, took the papers into my mech and he had no choice but to change em out after he had rebuilt the tranny) though as it is part of what's supposed to be done. Yes you can change em out with the tranny still in the vehicle. Check my early posts for alot more useful info on the tranny.

ramrugby09

I am not sure if the solinoids are my problem now. I did the manuel transmission test from the factory service manuel and the transmission shifts fine. So does this mean it has to be electronic?

regularguy412

By default, the A340H will allow itself to be shifted through the gears from 1-2-D,,when the solenoids go out. It's so you can get yourself home. I'd say, 'yes', it's likely solenoids. The transmission is shifted electronically and uses hydraulic pressure , in conjunction with the solenoids/valves/valvebody, to perform the shifts. Hydraulic pressure can be lost which will affect shifting. The pump can go out, or the seals within the transmission are worn enough to allow pressure leakage. I would think, tho I don't know for sure, that if hydraulic pressure fails, you get no movement , either from normal shifting, or by running the shifter up throught the gears. Be aware that the A340H has an integral transfercase that uses fluid from the tranny to do its shifting, also. There can be leaks and in the transfer case, as well, which will lower the hydraulic pressure.

I'd almost be willing to bet that it is a solenoid problem. It 'could' be that a valve in the valvebody is stuck and the solenoid doesn't have the power to unstick it. The valvebody can be removed and cleaned with the tranny in the vehicle. To me, the easiest step would be to drain the fluid, drop the pan and check the O/D solenoid for performance within spec and then go from there.

Mike in AR

ramrugby09

That sounds like what I should do. The tranny is still stuck in O/D. Could that mean that the O/D solinoid is stuck? If I pull it apart will I need to replace seals or anything like that? O-rings? Are those all dealer parts?

regularguy412

It could mean the O/D solenoid is stuck, or it's not working at all, or that it is OK, but the valve it operates is stuck. I believe replacing seals requires a removal and tear-down of the transmission. You should be able to get parts from the dealer. There may, however, be less expensive sources. (Did a quick online search but came up empty) Be sure to determine the auto tranny you have. There may be subtle differences between the solenoids -- both for the various gear shifts and between different trannys. There is an A340H, A340F, A340E and A43D. Check here for more info : http://www.off-road.com/toyota/tech/other/4_dts.html

MIke in AR

ramrugby09

Ok, I have pulled the pan off of the tranny and each of the three solinoids that I could see. I tested them per the Factory service manual, they all work perfectly. Is there a separate O/D solinoid? If so where is it? I also pulled the valve body and the only thing that I can see that may be the culprit is one of the plungers that is on top of the valve body(I'm not sure what to call them) does not move smoothly like the others, it kind of hangs up and makes a metal on metal noise. It is the one on the end on the side that has three in a row. Also is there a diagram of how to put back the parts that come down on top of the valve body...? Thanks

regularguy412

If you have a stuck valve, that could well be the problem.

I'm gonna assume you have an A340F tranny. This link should help with re-installation:

http://personal.utulsa.edu/~nathan-b...52onvehicl.pdf

I believe the O/D solenoid is nearest the rear of the transmission.

Mike in AR

ramrugby09

Regularguy thanks greatly for all of your help. The problem I am having with reinstallation is all of the springs and small rods that are under the valve body. I have a small tube that has a rubber end several springs and a plastic peice with a ball bearing attached to the end. When I took out the valve body I was laying on my back so I didn't see exactly where they came from. Is there an online parts fiche that shows an exploded view? Also is there a test to see if your vales are operating properly? Thanks again

regularguy412

Hmmm. Seems like I remember seeing one -- 'somewhere'. I'll search around.

MIke in AR

ramrugby09

well I checked the valve body and the valves seem to move fine. Everything looks brand new when I opened it up. My only problem now is I am not sure how the springs go back on top of the valve body. If anyone has that part of the FSM or a exploded view of that part of the tranny I would greatly appreciate it. The tranny is a A340H. Now that I have ruled out the most common problems where should I go? The ECT ECU? Thanks

regularguy412

I suppose the ECT ECU could always be considered as a source, but from what I have seen on the boards,,the ECUs are usually not at fault. I would hazard a guess, but don't think it will be what ya wanna hear. The whole tranny is hydraulically actuated. There is probably some kind of pressure loss inside. That could be the pump going out, or the seals around moving parts worn out. If it's either one of those, it means pulling it out and rebuilding.

When I thot I had a transmission problem,, I took it by a reputable shop and had them drive it with me along for the ride. The diagnosis they gave was , 'there's no problem ' that they could discern, just by driving. I'm glad I did that, too, cause it turned out to be a bad fuel pump. Maybe see if you could get the problem to reproduce itself with a local transmission tech along for the ride.

Mike in AR

ramrugby09

Thanks for all of your help That sounds like my final option. I had the tranny rebuilt about eight months ago and when I pulled it apart everything seems new. Once I get it back together I'll take it back to a shop.