Well I've searched and can't seem to find anything related to my problem.
First my tranny won't shift into O/D. This started a few months back. I changed the fluid and filter and the thermostat. No help. I haven't tried the temp sensor but I will. Lately I have have a worse problem. When my 4Runner is cold it will shift normally for about 10-15 minutes. After that it drops into second and won't upshift at all. After it cools down from sitting for several hours it starts the pattern again.
I've pulled the codes and there are none. Fluid level is good. Is my tranny fried and ready to be replaced or do I have anything I can check?
Thanks for any help!
Hope everyone has a good 4th of July!

 

Sounds like 1 & 2 shift solenoids. This is how they work. 1st gear no. 1 on, 2 off. 2nd gear, both on. 3rd gear, no. 1 off and no. 2 on. OD, both off.

 

Thanks but shouldn't it be throwing codes to that effect? I would love to be able to change solenoids and fix the problem just don't want to throw good money after bad if you know what I mean. I guess the next step would be to pull the solenoids and test them according to the FSM right?

 

this might be a pain but try to disconnect the connector for the solenoid harness. The solenoid harness comes out of the driver side of the trans near the rear. dont confuse the trans and transfer case. if you follow the harness to the connector which I believe is somewhere around the top of the transmission hear the bell housing, maybe leaning toward the passenger side. When you disconnect the trans solenoid harness you are then just able to manual shift. L=1st gear, 2=3rd gear and D=4th gear. However the tc will no longer lock up either. If you are able to manual shift fine then the trans is ok and you have an electrical problem. more than likely the solenoids then.

So if your trans is ok then you can test the solenoids in the transfer by just putting 12v to them from the car battery. If you here the solenoids click then they are fine and you have something else going on outside of the trans. To check the solenoids you will have to drain and remove the trans oil pan. This might be a good time to add new fluid to it when you replace it. Dont over fill the trans because they really really dont like to be overfilled.

 

BAMF, did I read correctly. If I wanted to trouble shoot whether I have problems with which ever solenoid, I can disconnect the ECU input (electo controlled trans etc.) and shift it manually? Previous owner of my 89 4runner dropped about a grand having the stealership install a number 2 solenoid. Your diagnoses procedure is interesting but I'm wondering whether the electrical system involved in running the 340h is something one should disconnect in trying to find the problem. It would be handy tip in the tool bag that's for sure. Also, you mentioned that when shifting through L, 2, and D where equivalent to 1, 3, and 4 respectfully. Is second gear a bypass gear? I thought that when shifting manually, if in fact the ECU controlling it was disconnect, that 4th gear (overdrive) would be missing as it is either on or off depending on whether you engage it. Hope my questions make sense as this is really good straight forward way to diagnose tranny issues.
Harold

 

Ok I disconnected the wiring harness and did road test. Here's what I got.
L-started off normally
2-no change in gear
D-upshifted normally
So it would appear there is something wrong with the transmission missing that shift in 2.
I guess now it's time to go to a shop or are there any other things I can do? Mabye drop the valve body and see if there's anything sticking? I can't really afford a rebuild at this time. Can I continue to shift manually without hurting anything worse?
Thanks for the input everyone!
Chuck

 

ploch out of curiosity, how difficult was it to disconnect the wiring harness to your tranny?

 

Get ready for a long response. I have done alot of research and experimenting with the electronics in the h.

With the solenoid harness connected, the park nuetral switch sends signals to the ecu to let it know where the shifter is located. If the shifter is in L the park nuetral switch tells the ecu that the shifter is in L. The ecu the activates the solenoids so that the trans is in first gear. The same with second. Second is only availble electronically. Just the way the valve body was designed. Not a bad idea in my opinion.

Diconnecting the solenoid harness on HELPS in troubleshooting. If you have issues with shifting and you disconnect the solenoid harness, and find out that you can obtain 1, 3, and 4. Your problem is more than likely electrical. So then the next set is to try and find a bad solenoid. Kind of a pain but easy. It only takes about an hour to find a bad solenoid and replace it and put is all back together for a toyota mech. Maybe two. I can believe the previous owner paid $1k for it. Unreal. Just drain the trans drop the test pan. And BAM solenoids are right there. one bolt and it comes right out. Very easy. A dealer solenoid i think is only about 200 possibly 300 at the most. You can find them cheaper else where new.


Here is an idea. This is totally up to you though. By no means am I saying this will work. Just a thought. A buddy of mind noticed the h slipping. added a bit more fluid over a good period of time until eventually the trans OT light came on. pulled over immediately. let it cool. was able to drive it home. Next day. couldnt get the truck to move. At this point he got lucky and a 3.4 became readily availble and he just did the swap. He took his trans apart just to se the damamage and all the clutch packs and everything looked really good. nothing was burnt. So this raised the question, What if we just swapped out the valve body??? Couldnt test it because the trans was already torn apart and out of the truck completely. Maybe the valve body just got fried from the AT fluid running through it. Swapping out a valve body could be cheaper than having the entire trans rebuilt when in fact it might not need it.

You might have just a bad valve body. Up to you if you want to try my theory. Just a theory because it has not been proven.

 

If not apparent already 2nd and 3rd share the same valve in the valve body. Just depends on where its opened or closed. This is why im thinking it could just a bad valve not closing or opening all the way maybe just stuck in the middle or leaking somewhere

 

Very good info BAMF thanks! Is it possible to rebuild the valve body to fix the sticking valve if that's what it is? I don't really have transmission experience except for swapping so is it something I might be able to do?

And Harold no it wasn't difficult at all...only took a few minutes once I figured out which one it was. It's on the passenger side hanging down by the bell housing just like BAMF said. Hardest part was getting a small screwdriver in to pop it loose. But we all know that Toyotas don't always give us much room!
Thanks!
Chuck

 

When it comes to the valve body thats where my knowledge comes to an end. Im assuming it probably could be rebuilt. There is performance shop it NJ ( I think) that makes some mods to the 340f valve body so that people can run the supercharge without burning up there trans. I have never compared the to but in my opinion I would think that the f and h would have identical valve bodys. the only difference between the to is the tranfercase. I cant remember the name in the shop but I think it is listed in mt_goat's thread when he did his 3.4 swap. I was thinking if you could come across a cheap valve body from a junk yard a put it in and see what that does. If there is no change with that then the clutch packs could be done and it that case it is just better to have a new trans. I have heard of too many people having any good luck with there trans after it has been rebuilt.

 

Thanks for all the info BAMF. I did another road test after she had warmed up, which doesn't take long here in Texas, and once I had shifted into drive it kept downshifting again. If I can't find a good one to swap out it might be time to drop in a 5 speed which I'd prefer anyway. The brisket's almost ready so have a good 4th and thanks again!
Chuck

 

This doesn't sound like exactly the problem I had because my transmission would shift when I unhooked the solenoid wiring, it shifted like it was supposed to. My problem ended up being in the computer, it seems some japanese ECU's will leak fluid out of the electrolytic capacitors and ruin the mother board in the ECU. There is a company in FL that fixed my ECU for $250 which included return shipping, and an 18 month warranty. Tranny works great now! I also had a 343f tranny with a diesel set up, not a 340h.

 

The only codes you can get for the solenoids are electrical problems. If they fail mechanically, there will be no code. With the manual shift, if you didn't have any change from L to 2, and there was a change into D, sounds like shift solenoid 2 is bad.

 

So it might not be a bad idea to get the solenoid kit and change them out you think?
I'd much prefer that to a new tranny or a swap...much less work in the long run.

 

Possible but very unlikely. The whole point of disconnecting the solenoid harness is to rule out solenoids. Like i said you can test them before you order a kit. I would check to see how that goes first.

 

Yup I'll run the test on the solenoids and let you know what I come up with. Hopefully sometime this morning.

 

Ok I checked the solenoids and 1 and 2 are functioning. The TCC solenoid is not. In fact the little black end that looks like a plunger is broken off. When I pulled that one the piece fell off. Could that be one of the problems I'm having? Still gotta finish putting the bolts back in the pan and refilling but it got a little hot. It's 102 right now...

 

possibly. I would try to replace it before putting the pan back on and then having to do it all over agian. I have absolutely no idea how the valve body functions but that could very well be your problem.

 

You only have torque converter lock up in 3rd and OD. How did you test the solenoids?


also check these seals