a340e ma70 NO reverse.tranny info please?

[petespipes]

I searched a340e and found some info but still not able to sort this out as im not very familiar with autos at all.

I recently aquired an ma70 supra turbo which is stock.possibly mistreated.about 225000ks.

Apparently the auto lost ability to drive very quickly quite recently and when i recieved it the car would not drive forward or reverse at all.There was no indication of even selecting a gear.

After reading posts on toymods i drained tranny fluid and dropped the pan,cleaned mesh filter,replaced with fresh oil and bingo! Forward gears and reverse OK with rear wheels in the air.

Next tested with car on ground and forward gears OK but no reverse.

Considering the tranny selects reverse and the wheels turn OK without load i am happy that the tranny at least selects reverse OK.After that im lost.

What can i check next? I am able and have tools and time,happy to take any parts etc for testing but dont like leaving an open cheque with my car at a workshop due to lack of knowledge.

Any guesses as to the nature of the problem?

[brett_celicacoupe]

tried doing the tests in the mkIII TSRM?

http://www.cygnusx1.net/Supra/Librar...tion=AT&Page=1

[petespipes]

thankyou.a very useful resource if you have an electronic problem.

I used it to determine i did not have an electronic fault code,but as the gearbox selects gears when it should i was confident there was not an electronic problem.

I feel the problem is a simple hydraulic [or lack of] problem and need input from someone who understands the a340e.

the info supplied by the guide [transmission is faulty] is not useful.Still i have stored the address as a very useful resource,thanks Brett.

[sideshow]

reverse does not work thru any electronics

so if the shifter selects some gears and when u select reverse u get nothing

i think that the auto is stuffed im pretty sure its a mechanical prob not elect

[brett_celicacoupe]

the epicyclic gears require 2 inputs to create an output.
the 2 inputs are the engine and being locked relative to the casing.

since the engine is actually spinning, the problem would most likely be in the locking mechanism. im not sure what specific gear locks for reverse though.

[sideshow]

in other words throw the auto out heheehe

[thechuckster]

Pete- talk to wilbo about whether one of his (growing number of) soarers might be able to donate/sell you an auto gearbox... it might not be strong enough in the long run (they're all behind 5/6M motors), but if you're just after something to get you going?

[MS-75]

I had this prolem a few years ago.

Trans required serious re-build.

Get a second hand trans dude-that one is most probably dead.

[Ribfeast]

Clutches are probably worn out. When I blew up my auto, I lost reverse, 3rd, and 4th all in one hit. I think they all run off a common clutch pack. Drove around with just 1st and 2nd for a month. It would go into reverse, and on really level ground would reverse slowly, but not up any kind of incline.

Sent the valve body to MV Automatics for them to kit up, and they found a large amount of clutch material in it
Bought another auto from a wrecker for $330 + shipping.

[petespipes]

Wow,doesnt sound good.I have sold these boxes for $50 in the past.....Is the a340e behind a 7m cressida for example going to swap into a 7mgte ma70? sorry havent searched this.
edit.just spoke to michael of MVautomatics. he says "most common failure of these boxes is 3rd and reverse clutch pack" and suggested purchase of another box ie mx83 cressida a340e.
Will go this way,cheers to all for the assistance.

[Ribfeast]

Hmm I always thought it was the 2nd gear clutch pack that normally went. They usually upgrade them to 6 instead of 4. Not sure how the N/A box will handle the turbo, anyone know if they are different?

[petespipes]

MV's Michael said the later model boxes did the second gear clutch pack??? I have no idea.........

Yes,any accurate assistance re which a340e donor cars trannys will swap into the ma70 supra turbo [7MGTE stocker] would be useful thanks.

[MS-75]

Yes they are different (turbo to non-turbo)-more clutch plates in second I think-but I can't quite remember ATM. I'll check the manual I have.

Yes second gear is a weak point in the A340, but the big failure is that the 2nd gear sprag lets go. (until the motor is making pretty serious power it should hold up though-mine let go at just over 450rwkw.)