Frknswt

After searching the web and checking locally, I could not find a used automatic transmission/transfer case for my '90 4runner so I bought a full rebuild kit with steels/clutches/gaskets/seals.
I would have to agree with one of the other members here that they are a "monster". There is a multitude of gears and clutch packs and other things that I don't have the proper name for. It is very time consuming but can be done if you lay everything out neatly and orderly. I put each part on my cleared off bench and labeled them with a number in the order which they came out. I should mention that I had no reverse, or rather, a very weak reverse. I found the problem in the very last clutch pack to come out, which is the first/reverse pack. The clutches were severely burned (you could scrape away the clutch material with a thumbnail) and the steels were discolored. Up to that point I was getting worried because everything else looked great and measured easily within specs. I beleive that someone has been in this trans before and packed these clutches incorrectly. When I reassembled the same pack with new clutches and steels in the same way that it came out there was no gap at all between steels and clutches. Everything was really compressed. After reviewing my rebuild book and an online book I decided that the large round spacer that was in there did not belong. It's not shown in any diagram I found. I did, however, have to add an additional steel to take up some space in order to get the gap within spec.
While reassembling the tail end of the trans I snapped off the vehicle speed sensor tip. I continued the reassembly process and ultimately got the thing installed back into the 4runner. Yesterday I filled it with fluid, started the engine and went through the gears to get the fluid distributed. I knew the VSS was an issue but decided to rig it where it would, hopefully, work. It did't. When I pulled the truck out it seemed to slip a little in reverse but then pulled stronger. Forward did the same thing. I figured it was the fluid still forcing out any air pockets. Not so. It would not shift out of 1st and ultimately would not even engage any gear. That was made worse because I drove it about a mile when this happened. After going through the gears and revving the engine it finally engaged first and I was able to turn around in a neighbors field and get home, still in first gear the whole way. Total drive time was probably 15 - 20 minutes. Now my fluid has that stinky burned smell, but still very clean. I'm hoping that I didn't do major damage to the clutches I so painstakingly installed. What do you guys/gals think? I most certainly need a new VSS, which I'll get tomorrow.
That's my transmission story so far. If anyone has a question about my experience, I'll be happy to share.

mt_goat

Wow, can't really help with rebuilding one. But I do have a good used A340H just south of you. Do you have a 3.0 or 22re?

Brenjen

Good luck to you; automatic transmissions are one of the things I am helpless as a kitten about. I can change one out no sweat but cracking it open & playing around in all that mess confuses the crap outta me. I had a tranny guy that lived across the street from me for a while, he tried to explain all the stuff to me; I knew when I wasn't gonna understand what he was saying when it started out "Look man, it's really easy...."

Frknswt

Mt_Goat, We PM'd about your trans several weeks back. It was a bit out of my price range. Thanks anyway.

Brenjen, I thought the same as you about A/T's but decided to throw caution to the wind and crack this mystery. It turns out that I could do the job given a good rebuild manual and lots of patience.

I'm still curious about what some of you think about the burned smell of the fluid now and if you think 15-20 minutes of run time and about a mile of driving could have severely damaged the clutches.

breknraj

I'm no fan of automatics, but I just wanted to find out how much cleaning (and with what) you did with the case and parts before re-assembly. I'm just thinking that the burned smell might be residual from the original failure.

Good luck with this project!

Frknswt

The interior of the case was very clean so a just wiped it out prior to reassembling. All of my work may have been for naught since I think I may have burned it up tonight.
After replacing the VSS on the trans I gave it a test drive. Engaging reverse seemed to be good but drive was slipping. If I dropped it all the way into L the truck would move forward a bit then immediately stop, as if I put it in R. I could take off in D or 2nd but it was slipping the whole time. At 65 mph it seemed to do alright but I'm sure it was not locked up, but it's hard to say. Then I tried to move it around the yard and it didn't want to go so I revved the engine more and the Check Engine light came on about the same time smoke came rolling out from under the hood. Upon popping the hood I could see that the smoke was coming from the rear of the engine. I looked throught the wheel well and could see that the smoke was coming from the transmission. I don't really know where that much smoke could have been coming from but it disipated quickly. The Check Engine light and A/T light both gave me a code 42. What the f..k? I just put a brand new one in!!! This is all getting extremely frustrating. I checked the cable adjustments as outlined in the diagnostics. I haven't figured out why it won't engage/shift gears. Maybe the trans is toast now but I'm wondering if it's the transmission or something else. It did, however, shift in the forward gears before I rebuilt it. Now it seems like reverse is not bad but the forward gears are not working.

SEAIRESCUE

Well, I too have gone through a 340H to repair it and took it down to the one/reverse clutch pack. I was not intimidated by the clutch packs and band but when I got to the overdrive section I was concerned. Those little carbon snap ring looking seals that fit under the aluminum hub were tough. The transfer case assembly worried me. But, I had three manuals and took my time. Actually put it together 3 times before I was confident that it was likely OK. Did you pressure test each clutch pack as you put them into the case? Did you replace the "O" rings in each clutch pack piston assembly? Yes, it is a monster. I would drop the pan, remove the valve body and pressure test the packs and check their end gaps unpressurized. That will validate the clutch packs good/bad status. Check the band assembly for correct assembly on both ends. Make sure the 3 aluminum spools are correctly located in their holes with correct springs before putting the valve body back in. Refill and cycle the transmission to get the fluid level right before another road test. A pressure test is necessary at this point. The kick down cable will set the base line pressure and as the cable is pulled the pressure rises. Get its adjustment correct. That is all you can do with it in the car.

Best of luck. May have to get a shop's opinion if problems persist.

My $0.02

Whitey13

Pics?

buckz6319

I know this is a old thread but I do have a pic of what my used donor A340H looked like when I tore it down.I even separated the hydraulic transfer case from the transmission.This pic is every thing that is inside of the A340H except a few parts. I did all this on the donor A340H just to learn from, and decided not to tackle a rebuild on the one that is in my 4runner

mt_goat

I bet you have a nice pile of metric bolts now LOL.

iamsuperbleeder

now point out and name each part I see a pan and a bell-housing; that's about all I can' help you with, lmao

screw that mess... get a manual (as in a manual transmission, not an instruction book)

buckz6319

I do have some parts left if any one is interested...and lots of Metric bolts and the shafts are in good condition 23 spline I think

fsprandy

Still have the kick down cable?

buckz6319

sold the kick down cable

birdduck

looks as if this thread is old and tis be my first post and all....
i worked in a trany shop for a wile(aamco) and carefully watched the builder when i could.
on thing i noticed is he pre soaked all clutches in atf for at least an hour. the reason exactly? but probly to well get them saturated with atf to keep them from burning up before the pump could do so. and i could label almost 90% of those parts for yah....