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The Free Mod Series - Part I Quicker Transmission Shifting

97K views 154 replies 70 participants last post by  1252820 
#1 · (Edited)
Background:
We all know that the Automatic Transmissions in the Camry/ES 300 (both of the v6 4-speed automatics 2vz-fe & 3vz-fe A540E, 1mz-fe A541E are mechanically the same) are setup for comfort. The bad news is that they're slow shifting. The good news is that they don't hunt for gears under anything but highly spirited driving. The great news is that there is something we can do about it!

Theory:
Anyone that's looked into making serious power gains on any A/T Toyota engine will notice the second most important upgrade to the A/T is to upgrade the valve body. By raising the pressure in it, the shifts are much harder, and faster. This gives quicker shifts and also reduced wear on the transmission. (less heat is produced)

Most of you that poke around the engine bay will see two cables going to your throttle body. Obviously one is the throttle, but what is the other cable? A good guess would be cruise control, however that is incorrect.
The second cable is the "Throttle Kick-down Cable" and it's function is close to what the name says. It controls a valve in the transmission's valve body that can increase, and decrease the pressure in the valve body.
(A great example is the ECT button on the transmission. With it held down, the transmission shifts harder, and holds gear longer. The astute among you notice if you get on the throttle hard enough at the "right" RPM range the same thing is accomplished. This is because the cable is tighter the more the throttle is open.)

What we are going to do raise the pressure of the valve body, without sending it off to a transmission shop and spending $399 on a great upgrade.

Instructions:



The red cable is the throttle kick-down cable on *my* car in it's stock position (the nuts are in the middle). What we need to do is make the cable as tight as possible WITHOUT restricting wide open throttle. (If you crank it too tight, you can't open the throttle all the way.)

All you have to do is run the top nut in that picture all the way to the rubber stopper, then close the bottom nut on it. (as said above, this will probably restrict your WOT operation, so back off a little)

Your shifts will now be much quicker, and much firmer also. Possibly to the point of just being a really hard shift. Your car is not only quicker, but the transmission will go longer without burning fluid, and the clutches will last longer because they're not holding the planetary gear set as long.

*note*
Forewarning, the transmission will also shift into Drive and Reverse harder also. You can't have it both ways, everythings a compromise. If it's too much of a pain going into D & R back off.





*edit*
So many months later and so many still confused.




Just do that!



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Other Articles in the Series:
Part I Quicker Transmission Shifting
Part II Adding Airflow
Part III Taking Advantage of Intake/Exhaust Upgrades
Part IV Cheaply Monitoring the ECU & A/F
Part V How to pick up MPG, and sleep with her too!
Part VI Acing Aerodynamics
Part VII Cheap Water Injection
Part VIII Electronic Transmission Controller
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#2 ·
Haven't found any real difference in adjusting the A/T cable, over-tightening just makes it down shift too quickly and loosening makes it down after keeping it at WOT for like 10 seconds.

I didn't try extreme's but perhaps I'll try fooling with it a bit more tomorrow (weather pending).

Good info for everyone unaware of the cable though...

Just a FYI though, if you have a black box in your engine bay, inside of it is your cruise control cable and your actual cable that directly relates to your gas pedal, which is very good for taking slack out of the pedal itself). :)

:thumbup: :thumbup: This should be added to the FAQ. :)
 
#4 · (Edited)
just wondering if this works for an 88 camry v6 2.5L engines? gonna plan to do this due to my slowness at take offs and just plain going. but need more info on if it will on my car.

also im not too sure what yer exactly saying but when you say to move the top bolt to the rubber stop up above it or next to it then move the bottom bolt to close it(that part i dont get). do we have to lift the cable to get the bottom nut to the top nut or are u saying move them in the opposite direction. or i just thought of this because the cable becomes loose screw the bottom nut until the cable becomes tyte?
 
#5 ·
dna59 - Good question. Like I said this *improves* reliability over stock, as the transmission clutches are not pushing the planetary gearset in and out as long, and the fluid doesn't build up as much heat.
alex86 - i listed the 2vz-fe. it uses the same basic A540E transmission as the 3vz-fe and the mod will work for you.

To make it easier guys, this mod works on any Toyota that has a kick-down cable on the throttle body.
 
#9 · (Edited)
Toysrme,
Hi would you recommend this mod for a first time car performance modder? I was more of a car audio guru until now :)

It doesn't appear to be that hard to do, but the main thing im worried about is the hardness of the gear changes after the mod.

so D to R,N will be harder? how about L2 and L1..?

Anyhow, this is my first post on the board, so hi :)
 
#10 ·
Welcome!
Yes, every time the transmission shifts it's gears it will shift hard. Going into drive and reverse, through the 4 drive ratios (1,2,3,4)
Sure, it's a great first mod. Noone else seems to have done it, but it'll give more improvement than anything else you can do for no-very little cost.

The beauty is that if the changes make you uncomfortable, you can easily open the hood and start moving them back the other direction. Everyone will find their own balance between "the transmission shifts great, I can deal with it going into drive and reverse harder because the gear changes are quicker.", and "I want it to shift faster, but I can't stand the hard shift into drive and reverse".

It's seriously not technical. You twist a nut, pull the cable fairly taught, move the second nut to hold the cable where it is.
 
#142 ·
Just found the mod

It's seriously not technical. You twist a nut, pull the cable fairly taught, move the second nut to hold the cable where it is.
Maybe it's just a few turns with a wrench but it works. I was a bit skeptical but I'm here to tell you that the shifting is more positive, and the throttle seems a bit more responsive. Even though it's an old thread, I just found it and I'm glad I did.

The pics that were posted didn't apply to my 1MZ-FE, 6CYL, 2000 Camry, so I took some in case anybody want's to see what it looks like on that motor. Like your post the throttle is on the right, and the transmission is on the left, with a bit of a different placement.

I also put a mark on the lock nut (see insert) so I could keep track of what I was doing. Turned it one turn, went for a drive, then another turn, and then finally a third turn. That seemed to be the best for me. Shifts nice, and at WOT it upshifts fine. Thanks again Toysrme for the mod. :D

 
#11 ·
i did this on my aussie 94 3vz (its the lower cable you cant miss it, it goes straight to the tranny, the throttle cable goes to the air sensor thingy) and oh boy it shifts damn quick now. you gotta fly past the R so it doesnt engage, takes less then .5 seconds, makes the engine feel really positive between gears, not lazy and smooth. i also tightened up my throttle cable as well, there was about 1.5cm of freeplay b4 it started pulling.
 
#12 ·
well i screwed the other cable in as far as it could go i can only feel a quick response from the engine from shifting at lower gears and very slightly on higher gears but imma start messin with the throttle cable so that i can get more out of the engine hopefully wont frick up the car:D
 
#14 ·
i dont noe ive done wat i can with the other cable not the throttle and it does shift fast but doesnt give much kick bak when it shifts only in low gears must b doin something wrong.

so far i did screw it so that i got barely any threads left on the cable but there is still some slack on the line. am i doin something wrong? i also did the same with the throttle cable and i did see that the car did launch faster cause it reved higher than usual. got any ideas to fix?
 
#15 ·
Toysrme said:
You are so welcome. ;)
I try and do nice things and give you guys free mods, then get flamed sheesh!
Gotta love it:lol:
well nobody is forcing you to share your free mod info...so don't be surprised when some people are gonna flame you or whatever :rolleyes:

as i have said before opinions are like assholes, everybody's got one :)

Keri
 
#16 ·
yes i rember when i did my free mod about oh 2 years ago .... the links still work on it too :disappoin

but hey thanks for this, seriously i forgot all about the kick down cable it helped with my tranny slipping ....... mucho props to you home boy
 
#18 ·
All you have to do is run the top nut in that picture all the way to the rubber stopper, then close the bottom nut on it. (as said above, this will probably restrict your WOT operation, so back off a little)
this is confusing... do you mean, screw the top nut to the stopper, then screw the bottom nut so that it is touching the top nut that i just screwed up to the stopper, so it looks like the picture, only higher up on the cable?
 
#19 ·
For the '94+ Camry with ECT transmission, the line pressure readings will be off by adjusting the throttle valve cable like that. This would actually trigger a CEL.

This mod is great to tailor the transmission to shift firmer at partial throttle ranges.

At full throttle however, it will still shift the same because the total line pressure has not been increased. Total peak line pressure can only be increased by a recalibrated valvebody.

So if you need your transmission to hold more power, there is really no choice but to get the valvebody done/build the transmission.


Benefits of adjusting the throttle valve (TV):

- more aggressive/earlier downshifts
- less slippage at partial throttle ranges
- tranny actually runs cooler because fluid circulation is increased

Misconceptions:
- does not make the car shift firmer at WOT
- does not make the transmission to hold more power than it actually could
- will actually trigger CEL for ECT transmissions
- would cause more wear and tear to engine mounts because of shudder during R -> D, or P -> R, etc... A properly calibrated valvebody would not over-increase line pressure during idle
 
#20 · (Edited)
It triggers a CEL? I've never known it too.
- does not make the car shift firmer at WOT
I know, that's once reason I cited the ECT on/off as an example in the original posting. You can ge the same shifts with the ECT button on the trasmission being off as if it is on if you know how to get on the throttle at the right circumstance.

My fault if someone got a misconseption. I should have spelled everything out in the first place, but I figured noone would even both reading what I posted anyway heh.

I also doubt that if you adjust it to your liking (I doubt most people will drive with it all the way up because it does shift quickly and harder into gear) that any mount issues will arise. I honestly doubt any mount issues will come up to begin with if a car's mounts are in OK shape to begin with. (Not all ratty on the inside)


At any rate, good info Tony! 'cource it would come from you wouldn't it LoL!
 
#21 ·
i have a 96 camry le 5sfe. will this work with my car. and if so where is this cable in my engine.
 
#22 ·
I did this mod last night and I have no engine lights on (if thats what a cel is(sorry about the lack of knowledge)) I haven't tried playing with my ECT though its always on. I didn't do it to the rubber stopper about 1/4" below it. There is a difference in the way it shifts, my gf noticed last night when I picked her up from work and I didn't say a thing about it.
 
#23 ·
^^

Almost forgot about this thread... :)

Anyways, you can check the full Toyota manual on the A541E auto trans. It states that if the throttle valve (TV) for the transmission is improperly adjusted, it would trigger a check engine light.

If your CEL isn't on, it means that your TV is probably loose to start with, and now you are slightly on the tight side. Enough to feel a shifting difference, but not enough to trigger the CEL.

I had mine tightened pretty much all the way (yes I was greedy) when I was still on stock transmission and it triggered the CEL after a couple of driving trips (2 trip logic CEL).
 
#26 ·
That's really strange Tony. I've never heard of that from anyone else and it's been a trick on a ton of Toyota cars for a long time.
I believe you though ;) Maybe it's just a CEL on the A541e because it interfaces with the ECU more??? I've never heard of a problem on A540E's and A340E's.

JetspeedCamry I don't know. The tighter the cable, the
 
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