NetG

My trans had worn/shot clutches, nothing else was wrong. The only fix for ME was to have the trans rebuilt. It had 290,000 original miles (more than 470Km). At that mileage a rebuild isn't unusual.

A rebuild had better include all seals and clutch parts. If the seals needed to be replaced I don't understand how the clutches weren't in need as well unless you just had really low miles or the clutches ONLY were replaced earlier...that sounds very strange.



Xapar...I'm having a really hard time understanding what all you've done to your car. What do you mean you "did the radiator"? Drained and refill the coolant or did you totally replace it?

Sounds like you ran the car with low fluid and even in a brand new car that WILL destroy the transmissions internals. The reason you had to rev high to shift was so the tranny could build line pressure...that's a major red flag as to why it's slipping now...you may have messed up the transmission internally as a result. You could have burnt the clutches or ruined the oil pump.

Next you mention some sort of alternator alteration? Iit sounds like during that you may have zapped your ecu or a fuse via pos wire touching something it shouldn't have.

Did you check ALL your fuses and relays after the alternator tinkering?

Also make sure you've replaced ALL your ground wires you may have taken off...take one ground wire off and you can see a HOST of CRAZY problems that will have you sending the car to the crusher. I had a 93 accord where i left off one little ground wire, blinkers on one half the car would work, dash lights were screwed up, and one headlight was dimmer than the other...turns out it was a pretty important ground junction.



If the grounds check out why not just go to a junk yard and get a used ecu instead of taking this one apart? You'll need a new one anyway right or is it just really easy to swap those capacitors? More power to ya on that front From there you can determine if you need a tranny rebuild but considering; you can't get it to move forward with manual shift, there is ONE main clutch for all forward gears, and the low fluid run, and that these issues existed before the alternator tinkering all makes me believe you need a rebuild. Hope you figure this out, I'm curious.

xaper

NetG, let me explain. The story goes like this :
- I changed the alternator and at the same time being in the garage the radiator
- While changing the radiator some of the atf poured out (then I thought it was engine coolant)
- Without adding atf I drove the car for about 3km
- Back to the garage, cleaned transmission filter, changed the pan seal and added atf
- The car was riding really well, even better than before, for 3 weeks or so when I reved it more than usual (with the atf level 100% right, as I checked it the same day) and the problems with the forward gears started.

Hope that helps explain my situation. As a matter of fact, thanks to all of your posts here I realised that it is not an electrical problem and my tranny needs a rebuild (as NetG explains above). With that being said, can you NetG please tell me how you did your rebuild, I mean where you got the parts. I have searched the ebay and there is a Rebuild Kit but I don't know if it is worth buying it and if it covers all the parts needed.


As for the ECU capacitors, I have already done the replace. It is not really that hard if you have already done that before (I mean soldering) and you have good equipment, as the original capacitors are soldered really firm.

LScowboyLS

A lot of diagnosing transmission problems comes from knowing the true miles on the car, and it's service history, if a well maintained LS400 has a shifting issue at 120K, it is very likely NOT to be internal, but at 250K+ miles, it is likely to be internal

xaper

I have followed the troubleshooting procedure and it is almost sure I would need a rebuild, and more specifically the forward clutch is the cause of my problems, yet if doing the job I would change the clutches and seals all over so that it serves for some more thousands miles.

For the moment I have a question regarding the transmission itself. The label on it says it is Aisin 30-42LE of which I have found almost no info. The "4" stands for four speeds and "2" should be the toyota self id, however I am not sure. Could anyone confirm that 30-42 translates into a340/a341 or this is some kind of a different monster.


LScowboy, I know the true miles w/o knowing the full service history, but in my case this is not relevant, as I did the full harm to the transmission. Anyway, the service manual to the transmission is v. good and the troubleshooting is really easy, if you have place and a bit of knowledge, giving you precise root of problem.

LScowboyLS

Aisin 30-42LE translates to A342E transmission, which is basically identical to A340E/A341E series

xaper

Update, might be useful for future reference.

I had my transmission rebuild. Despite what LScowboy said, I did it myself (with help from a 20 year old experienced engineer, his main field of experience was machine industry, but convinced me that it is no different than the transmission). The main cause of the problems was the forward clutch, which I changed as a whole. To prevent any other problems I changed all (or almost all, as I might have accidentally skipped some) seals (o-rings) together with new pan seal. I didn't go for oil filter change, as it required only cleaning with compressed air, however if anything happens it is easy to access that one. With the manual help I checked all the electrical connections and components of the transmission and I am sure they are all good.

So to sum all things up, the trans has been rebuild and what is most important it works. I have now better knowledge of how it works. Additionally I know that if something brakes down with it, it is a real pain to get it fixed - not because it is complicated, but because it takes a lot of time to get it out and then install once finished. The total cost in time was around 40 - 60 hours together (most of which I would say is the removal and installation of the exhaust). In money it was 17 litres of oil (totally, since I firstly as described had it replaced, when I realised this makes no difference) around $14 each, clutch parts where $150 delivered and the seals where around $35. Took a while, but was worth waiting I guess.
So if anyone fells like doing it on their own, I would suggest inspecting the exhaust. If it looks hard to remove, give it to someone else and leave the transmission for your own and you won't regret it. I asked some guys how much it would be to remove the trans and they said $80, so looking in the past I really regret the decision, however in my case they were busy when I needed them so to 'save' time I tried it myself.

Yotarip

XAPER,
Just out of curiosity, how would you rate the difficulty of your rebuild? 1 to 10, 1 = easy to 10 = extremely hard. I'm talking about just repairing the trans not the removal and installation. I have worked on a A340 and an A650 and I would rate them both at a 4. The most difficult part for me was aligning the clutches in the planetary gearset for reinstallation.

LScowboyLS

if you can do an automatic transmission rebuild yourself successfully, then you are qualified to tackle any repair on the car, as the tranny is the most complex part to work on. The only exception to this might be ECU repair and A/C, those are the other two areas that are definitely an art to do correctly.

anyone that can rebuild their own tranny and have it work well and stay reliable has my respect!

xaper

Yotarip, I really can't say, as this was my first transmission rebuild attempt - I don't know what to relate it to, however I wouldn't say it was anything more than 5. The most important thing is to remove all the parts slowly and store them somewhere as they were taken out. I agree that the installation is more demanding than removal and it takes several tries to align the clutch's plates, but doing sth for the first time is always the hardest.

Thanks LScowboy for your words.

NetG

New issue...will be taking car back to transmission shop. When it gets really cool, below 50...the car won't stay in reverse or d, either pops out or has to rev to move. Shifts slowly on the road and feels like it's slipping. Since it was JUST rebuilt it shouldn't be the friction plates...maybe they didn't do some seals? Fluid level is good if not a little over filled. When cold and you go from neutral to R or D there is not "jolt" when it engages either. I'm kinda pissed I'm having this issue after it was rebuilt.

Once the engine warms up the transmission behaves normally, jolts when going from N to R or D, doesn't need to be overly rev'd to move, doesn't come out of gear...shifts more quickly but I can still feel some slippage and power loss. Also the shifting, while improved, still isn't as quick as it should be...well it'll be going to the shop in a day or so...I didn't notice all this before because I was driving it easy (fresh rebuild) and it wasn't until the temps got low that I noticed the coming out of gear issue.

The friction plates and seals SHOULD have all been replaced with the rebuild but apparently something was missed or there is something else wrong. Is it possible that some solinoids are worn out, could they do this?

Gmach

This is a question for anyone but aimed at LScowboyLS..who may or may no still be on the forum. To place the transmission in manual, as described above, if the transmission still won't shift could that be a solenoid failure? We have a code 63 on a transmission that stops shifting as it comes up to temperature. Could this be because solenoid #2 has failed or is that code just coincidental with a larger problem?

dicer

63 is an open or short number 2 solenoid valve. So either the valve coil or wiring or connectors to it. The larger problem could be the ecu itself. Its really not going to be something to do with mechanical or hydraulic with in the transmission. With temperature metal expands and that could cause an open or a short possibly in the solenoid coil. I guess more likely an open where the wire pulls apart, its all just a guessing game.

Sc400dan

I bought a 92 sc400 and my car was only going in reverse.. replaced filter solenoids and torque converter with no fix.. I decided to just pull a trans from a junkyard and it fixed my problem.. the issue was the clutches and friction disc's were toast in the forward drive gears... no one really had a answer to the fix and I've been stuck on it for couple weeks.. hope this helps in the future.

hitachi