Auto Tranny Cold Shift Mode? Hard Shifting

[landtoy80]

Does the 87 Supra auto tranny have a cold shift mode like other Toyota trannys have where it wont shift into overdrive until the temp gets to a per set temp?

My tranny shifts hard, when I floor it, until the tranny gets warmed up.
It also shifts into overdrive when the tranny is cold.
If I drive it like a normal person, it shifts fine cold.

If the tranny does have a cold shift mode, I guess it could be the temp sensor off the thermostat???

 

[Nick M]

If you drive it like a normal person... *sigh*

Pick up the factory repair manual. The older manual had the trans section in it. The newer ones don't have the overhaul section, just some diagnostics.

 

[Poodles]

autos always shift a bit odd when cold... it's the nature of the beast.

you shouldn't be hard on the car until it's warmed up anyway...

 

[IJ.]

No OD till 60c engine temp.

 

[landtoy80]

No OD till 60c engine temp.

It shifts into OD today when motor cold. I guess I need to find out why.
I will test the temp sensor.
If the temp sensor is not working correctly, will that affect my cold and warm shifts?

I drove around today and when it was cold it shifted fine but later when I got on it, it shifted hard. I drove some more and it shifts fine.
Its like it shifts fine one time and hard the other.

 

[landtoy80]

No OD till 60c engine temp.

I get OD when water temp is cold.
I searched the Toyota Service Manual with no luck and found nothing about temp sensor for tranny.
How do I trouble shoot this problem so I can fix it?

 

[supra_man87]

I get OD when water temp is cold.
I searched the Toyota Service Manual with no luck and found nothing about temp sensor for tranny.
How do I trouble shoot this problem so I can fix it?

do you have super monitor or no. cause i found a self diagnosis for an auto trani in a haynes supra manual. i don;t and its alot like checking your engine codes. but instead of looking at the engine light, you look at the o/d off light. let me know what you have and i'll walk you through it if you don't know this already.

 

[landtoy80]

I installed a super monitor and there are no codes.
Does the super monitor show all codes or are there codes you have to check manually?

Before I installed the super monitor I checked the tranny via the Toyota service manual.
Maybe the Haynes manual is different???

 

[supra_man87]

I installed a super monitor and there are no codes.
Does the super monitor show all codes or are there codes you have to check manually?

this is am not sure of. you might have to find that out from someone that is more experienced with the surper monitor and has an auto

Before I installed the super monitor I checked the tranny via the Toyota service manual.
Maybe the Haynes manual is different???

and this i don;t think they would be different. i would just check the level, the trans link, and the basic stuff. but i know that my car, an auto, does sometimes shift hard when its cold. but when my car does warm up, it's fine.

 

[Zumtizzle]

Does the 87 Supra auto tranny have a cold shift mode like other Toyota trannys have where it wont shift into overdrive until the temp gets to a per set temp?

My tranny shifts hard, when I floor it, until the tranny gets warmed up.
It also shifts into overdrive when the tranny is cold.
If I drive it like a normal person, it shifts fine cold.

If the tranny does have a cold shift mode, I guess it could be the temp sensor off the thermostat???

In ECT power it won't shift up into overdrive or 3rd when hella cold. I dd'ed a Auto Turbo supra for 2 years.

This is bullshit you don't want to do, toying with a cold motor and trans maybe fun but its not fun when you go knock knock or get stuck in 2nd (common issue)

 

[mkIIIReed]

when the car is first fired up, and put into reverse with the brake pedal depressed, is there a really hard lurch? Mine started doing this as temps here in Tucson are starting to warm up (strange.) Or is this issue caused by something else entirely? By hard, it would seem as though i'm neutral dropping it. It also shifts like it has shimmed accumulators from first into second and second into third. no OD, of course. It does not have shimmed accumulators, but i like the hard shifts. both issues go away once its warmed up, but it did not used to lurch so hard, even during winter.

 

[Zumtizzle]

when the car is first fired up, and put into reverse with the brake pedal depressed, is there a noticeable lurch? Mine started doing this as temps here in Tucson are starting to warm up (strange.) Or is this issue caused by something else entirely?

I came to the conclusion this is caused by old Dex II, and it's time to do a drain and refill.

Dex II from toyota has an addictive to make it smoother.

Knowing some of you on this thread; DO NOT MIX DEX II and DEX III they're not compatible!

 

[mkIIIReed]

I just had the trans flushed by a local mechanic, and he assured me that they fluchsed everything, not just a top-off. However, i woudln't be surprised if he filled the whole trans with dex III. would that cause the same issue? Like i said before, it feels like the accumulators are preloaded to hell. It happens regardless of engine temp... its all about how long i've been driving. Usually takes 10 minutes or so before hte problem goes away. Not trying to thread jack here... i think solving this issue could help the original poster as well.

 

[jdub]

Did he clean the filter (screen) in the pan?

Have you adjusted the line pressure up (throttle) cable?
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=AT&P=19

Is the O/D Off light on the tach blinking?

 

[mkIIIReed]

I have checked both adjustments in the past, according to the TSRM, trying to diagnose another problem. At the moment, i know the throttle is correct, and the shift lever functions as it should, i do not feel that it is out of adjustment, but i will follow the procedure and adjust again to eliminate the possibility. On the invoice (January 4th, 2008) the mechanic noted that he did clean the screen, and the invoice lists Castrol Dex III ATF, not the Toyota stuff. The kicker for me is that the problem goes away when the trans is warm, but it is violent when it is cold, enough to cause concern. It only started about 2 weeks ago, and it is getting hotter by the day here in Tucson. I am still open to more suggestions. Thanks!

EDIT: and no, the O/D off light does not blink.

 

[jdub]

Well, it's not the Castrol Dex III...that's what I use

The flush *may* have loosened some debris in the tranny, especially if it has not been changed for a long time.

 

[mkIIIReed]

thats very much a posibility. I bought the car less than a year ago, and was told that the previous owner, while the only one, was rather neglectful. It already has a JDM bottom with "40,000 miles" because the old owner practically let the thing run dry (two quarts or more i was told). I am going to flush it again myself next weekend. there is agood write up on this, and i feel confident in my abilities. i'm going to check out the accumulators as well. Not exactly sure what i'd be looking for (in terms of damage, i know what accumulators are, mind you ), but i'm going to use the shimming writeup as a start. i'll probably do the modification while i'm at it and see what happens. Do shimmed autos usually lurch hard when the lever is moved from N to drive or reverse?

 

[Kckazdude]

Knowing some of you on this thread; DO NOT MIX DEX II and DEX III they're not compatible!

???
Enlighten me please. GM, who created the Dex II and Dex III spec, designed III to be a drop in replacement for II. Dex II has since been out of development for some time now. So please, tell us how they are not compatible.

 

[mkIIIReed]

???
Enlighten me please. GM, who created the Dex II and Dex III spec, designed III to be a drop in replacement for II. Dex II has since been out of development for some time now. So please, tell us how they are not compatible.

I think the main reason you wouldn't want to mix them is because it will screw up your service interval. If you're using dex II, you can follow the Toyota manual. Service intervals are different for Dex III, but if you mix them then it can be unclear as to when the fluid should be serviced. Its not like oil and water or anything, but there is a reason they don't recomend mixing them or using one over the other. Most companies have said Dex III is fine after the warranty has expired, again a product of service intervals more than likely.

 

[Kckazdude]

Dex III has a longer service interval. Even mixed with Dex II the service interval wouldnt be that adversly affected. Again Dex III is a recommended drop in replacement for Dex II. Not to mention you cant even get Dex II.