Auto tranny questions!!!!!

[supraman7mgte]

I have a few questions about the auto tranny in my 1991 supra turbo. The car is new to me for about a year and a half. I have done most of the routine maintenance things like changing the oil and other fluids,so i'm pretty hip to whats going on.Afewdays ago I noticed that the transmission started to shift bad,like when it's cold,it would take longer than the motor to warm up it seemed.Other than that,it shifted fine and gave me no problems. Now when I engage the overdrive,it dam near locks up the tranny at speed.I can turn it off,and it seems to be normal. Now Icheck codes to see if a solenoid is bad or what,no codes show up. Okay,it must be a dirty filter or something. Sure enough,the filter looks like it's never been changed,and there is a tranny fluid soup,it was thick! No metal shavings,no metal collected on the magnets...WHEW!! So I change the filter and the 1.7 quarts of fluid that the book says it holds. VIOLA!! Shifting through 1-2,2-3,and 3-4 are smooth. BUT when I engage the OD again it still wants to lock up!!!! The only thing that has been added is a tranny fluid cooler since i changed out the OG radiator to a aluminum one. ANY HINTS TRICKS OR IDEAS AS TO WHAT THE HELL IS GOING ON WOULD BE APPRECIATED!!!

 

[supraman7mgte]

Wait,hold up,there is no 3-4 shift change ooops

 

[mrnickleye]

3-4 IS 3rd to OD. So when you say it 'locks up' , what actually happens. Describe to us what takes place. Off hand, I am thinking the 'lockup' totorque converter is locking up immediately when it shifts to OD.

Also...go here to finish the trans service, which may help, and won't hurt.
http://www.supramania.com/forums/showthread.php?t=3179

 

[Nick M]

Are you driving off with the O/D in the off position?

 

[supraman7mgte]

When I take off and it shifts normally,everything is cool. But as soon as I put it in OD(at about 30 mph),it will lock up the tranny! I did not let it come to a rolling stop,I just did a Hank Hill,(wahaaaaa) and took it out of OD.It did it to my pass rear tire and freaked me out!Im not sure if it still might have some of the old tranny sludge in there or what.I'm going to stay out of OD for a week,and flush out the new/old fluid,and put in some more. I think there might be more bad fluid in the tourque converter.

 

[Allan_MA70]

sounds toasty to me have you been doing burnouts or towing?

 

[supraman7mgte]

No towing,but the occasional burnout. I think it needs serious service due to the lack of maintenance by the previous owner.Oh well,been wanting a 5 speed anyways! lol

 

[Allan_MA70]

stalling it up / burnouts without a LARGE trans cooler = toasty auto

 

[mrnickleye]

Well...that's a weird one. It sounds like when you put OD on, the oil pressure is being diverted to the wrong area. These trannys are computer controlled, so it may be in the computer. Maybe sending wrong signals somewhere.:icon_conf

 

[rakkasan]

No towing,but the occasional burnout. I think it needs serious service due to the lack of maintenance by the previous owner.Oh well,been wanting a 5 speed anyways! lol

Let me be the first in this thread to say that the A430 sucks ass. I have spent a lot on money to find that out. I had mine rebuilt (shoving a lot more clutches & friction plates in it, too) & I fragged it after less than 2k miles, and i'm not pushing more than 300rwhp. Do yourself a favor, convert to a 5-speed & rid yourself of the A430 headache.

 

[Allan_MA70]

if you where runing an A43D yes thats a MA61 auto designed for a stranged 5m-ge! an A340le has been proven to take ALOT of punishment with the right mods and be fully reliable for the street and track