The Free Mod Series - Part I Quicker Transmission Shifting
#1
Lexus Champion
Thread Starter
The Free Mod Series - Part I Quicker Transmission Shifting
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.
THIS IS NOT a replacement for a valve body upgrade..If you are making the power to justify one (250whp+) You MUST have one...
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, every things a compromise. If it's too much of a pain going into D & R back off.
Just do that!
*****************************************
Part I Quicker Transmission Shifting
Part III Tuning the ECU
Part IV Cooling
Part V How to pick up MPG, and sleep with her too!
Part VI Acing Aerodynamics
Part VII Cheap Water Injection
Part VIII Cheaply Monitoring the ECU & A/F Ratios
*****************************************
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.
THIS IS NOT a replacement for a valve body upgrade..If you are making the power to justify one (250whp+) You MUST have one...
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, every things a compromise. If it's too much of a pain going into D & R back off.
Just do that!
*****************************************
Part I Quicker Transmission Shifting
Part III Tuning the ECU
Part IV Cooling
Part V How to pick up MPG, and sleep with her too!
Part VI Acing Aerodynamics
Part VII Cheap Water Injection
Part VIII Cheaply Monitoring the ECU & A/F Ratios
*****************************************
Last edited by Pheonix; 07-02-05 at 07:09 PM.
#2
How much should I back the cable off the rubber stopper so I don't restrict WOT? BTW I believe you have mislabeled the cables in writing on the picture...
Last edited by Stub333; 07-02-05 at 11:31 PM.
#3
Lexus Champion
Thread Starter
They are labled correctly. The kick down cable is the one comming from the transmission. That is the outside cable on the throttlebody.
Go as far as you want, every cable will be a different size. OEM is near the middle.
I find most people like it around 1/4 thread on one side.
Go as far as you want, every cable will be a different size. OEM is near the middle.
I find most people like it around 1/4 thread on one side.
#4
Originally Posted by Pheonix
They are labled correctly. The kick down cable is the one comming from the transmission. That is the outside cable on the throttlebody.
Go as far as you want, every cable will be a different size. OEM is near the middle.
I find most people like it around 1/4 thread on one side.
Go as far as you want, every cable will be a different size. OEM is near the middle.
I find most people like it around 1/4 thread on one side.
Sounds good...but why will every cable be different when these are factory OEM cables? They should all wear in close to the same over the years, right?
#5
Lexus Champion
Thread Starter
Just one of those things. They stretch over time, wear, they may not be exactly the same to begin with. (Like how car wiring changes month to month at some plants).
Who knows.
Who knows.
#6
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phoenix...you rock man. i have a 97 ES300 and had my transmission replaced a couple of months ago because the reverse slip was getting worse by the day. the old trans was perfect in all of the forward gears except for reverse. this replacement has great working reverse, but the forward gears dont work as good as the old trans. it shifts earlier, and trans kickdowns are now accompanied by a noticable lag. also no matter how hard i try it wont rev to redline. could this cable be the reason?? anyone else who may know. plese feel free to drop your two cents
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#9
Lexus Champion
Thread Starter
No.
The newer 5 speeds rely on the TPS sensor and adjust it electro-mechanically.
It'll work on every Toyota A/T through the newest model transmissions. It works on most non-Toyota's also. Most makers used a cable connected to the throttle to adjust line pressure.
The newer 5 speeds rely on the TPS sensor and adjust it electro-mechanically.
It'll work on every Toyota A/T through the newest model transmissions. It works on most non-Toyota's also. Most makers used a cable connected to the throttle to adjust line pressure.
#11
Pheonix, you rock, I was noticing a little bit of lag in my tranny, especially when shifting from park to drive or reverse to drive, so I adjusted the cable and left about a quarter of an inch of space from the nut to the stopper, problem solved, also i like the noticably quicker shifts, thanks alot.
#12
Lexus Champion
Thread Starter
turboser1 this will not help slipping.
The line pressure is too low to engage the clutch packs. Low fluid, or bad fluid.
If it's been like that long, you've worn the clutch completely out - requiring a rebuild.
The line pressure is too low to engage the clutch packs. Low fluid, or bad fluid.
If it's been like that long, you've worn the clutch completely out - requiring a rebuild.
#15
i have a 2000 es300 and i can't find the throttle kickdown
i only have one cable which i am assuming is the throttle
should i tighten this or what?
am i lookin in the wrong place or can i not do this?
i only have one cable which i am assuming is the throttle
should i tighten this or what?
am i lookin in the wrong place or can i not do this?