swaz

Hi, im new to this forum.

I got this automatic 1986 A340H pick-up with a weird symptom. There is no 3rd gear, it is replaced with the overdrive gear !!

so, when i go, it shift 1-2 then OD-OD. Playing with the OD switch dont change a thing at all.

I got the factory FSM with the supplement.
I went thru all the testing procedures, and all seems electricaly OK. As the FSM suggest, i have disconnected the ECT so it can shift manualy 1-3-Od and this is what i have, so the 3rd gear is not toast.

I have taken the valve body all apart and found nothing but slightly damaged holes where check balls sits in. Changed the plate, gaskets, drained fluid, all solenoids ok, no change at all.

with a combination of manual shifting and the actuation of the 2 solenoids with a switch, i can get all the gears but have to select them manualy. Call it a temporary patch.

I know all the solenoid combination and what gear it should give. they are all fine and are powered when they have to be, but the transmission dont react to the third gearing selection under D, wich is solenoid #2 actuated.

here is a small chart that might help others...

D mode:
1st= #1 on only
2st= #1 and 2 on
3st= #2 on only
OD= none
Lock-up= #4 on

Since i got a second gear, the #2 solenoid is ok and they all test ok anyway. I realy went thru all the testing procedures by the FSM and i found nothing .
Feels like there is a seal that is toasted close to the clutches, but not into the valve body.
Or...
What could be toasted in it? I realy want to fix it, dont tell me to go to a 5spd plz :cry:

Thanks

toyaholic

my 89 4runner auto is giving me probs as well. Mine I believe is electrical though. I am getting codes for #2 speed sensor, #1 solenoid, and lock up solenoid. Have you replaced or do you know how much they run? My truck has to be manually shifted to drive, if left in drive it will not downshift. I am thinking that rather than three seperate items failing that it is possibly the ecu failing. Any thoughts?

cmc86

Bump for you.

Did you ever get this figured out?

I have the exact same problem. I changed all solenoids, and no change. It shifts fine manually (ecu unpluged), but with the ECU plugged in, it's like there is no third. I'm thinking it's the ecu because everything else checks out per the FSM.

cmc86

I troubleshooted some more, and everything checks out electronically, according to the FSM anyway. My next place that I am going to investigate is the valve body. I am thinking that the 3->4 shift valve might be stuck in overdrive position. I don't know thought. I have never worked on auto transmission.

A little background on the runner. It's an '86. I got it from a buddy who had to for about two year prior. He said it, as done it as long as he owned it. It didn't brother him, but it is bugging me.

Anyway, any suggestions are welcome.

scmedic

swaz / cmc

Have either of you had any luck figuring this out? I've got an 85 4runner with the same symptoms but haven't had time to dive into it yet. Any suggestions / info you might have would be greatly appreciated. If I come up with anything I'll be sure to send it your way.

Schooler

This is a guess, if the ecu and solenoids are all okay, check the Park Neutral position switch.

alex22psi

HEy It sounds like you are on the right track for diagnoses.....but i do agree check the manual lever position sensor ..or range sensor.....also do you know if the ECU is commanding 3rd gear when indeed your not getting it........Just watch tvoltage at #2 solenoid if its not supplying voltage to the solenoid when then the problem will be external....if it is than its internal........

patallen

Hi, long time no talk...
i kinda left the truck aside all that time, still no clue on this problem...i still believe its something to do with the valve body since it is very worn out.

...

scmedic

I think I've found the source of missing 3rd gear problem (at least in my transmission):

I had the same missing 3rd gear problem in my a340h and ended up pulling out the transmission and doing a full rebuild a few months ago. Everything in the geartrain looked perfect, but when I took apart the valve body, the retainer plug in the 3-4 shift valve was broken. In addition to all the normal rebuild replacements, I replaced the retainer plug and now the transmission upshifts and downshifts perfectly through 1-2-3-OD. One symptom of the problem I had previously was that the OD button didn't seem to work (ie it would shift into OD and it would not downshift to 3rd if you turned OD off) That problem is gone now and I can turn OD on and off at will...

I actually took some pictures of the rebuild and of the broken retainer plug and was going to write something up to post here but haven't had time yet so I'll include a brief description below:

The retainer plug is at the very end of each valve and serves to keep the valve and its springs in their valve body. To Access the retainer plug, you need to remove and dissassemble the valve body, then locate the valve you want to work on. The vale retainer plug is a small aluminum cylider which has a wide ends and a very narrow body (it looks like a spool with a skinny body). The failure in mine occured in the necked down region where the diameter is at a minmum. There is a small piece of flat barstock (little over 1/4" long) that is used to hold the retainer plug in the valve body. To remove the retainer plug (and the valve itself) just pull out the flat barstock and everything should come right out. As long as you have the valve body off and disassembled it's probably a good idea to remove, clean and inspect all the valves for good measure. Keep in mind there are a lot of little parts (valves, check balls, etc) in the valve body so it's useful to have a good manual available when you're doing this work.

Before I dove into this project, I had a hard time finding any online info on the 3rd gear problem, or on a340h rebuilds in general, so I hope someone out there will find this info useful... Feel free to get in touch if you need more info.

patallen

Hi SCmedic, i am more than interested to hear more from you.

PM sent.

thanks.

patallen

bump

anyone know this guy ? i sent him an e-mail to have more details but didnt replied...

thanks.