Kick down
Kick down
Drifting
Joined: Aug 2002
Posts: 2,617
Likes: 2
I am sure you know the kickdown is activated by the switch located under the go fast pedal. Not positive but I think the adjustment for your cable is on the crank near the throttle cable. Steve C is the resident expert here. You might try to chat with him. I'm sure someone else can give more insight than me.
Instructor
Joined: Jan 2006
Posts: 172
Likes: 0
From: Wickenburg, Arizona
I dont know if the kick down can be adjusted, it is an eletrical connection that tells the shift computer to down shift if the rpm is within a certain mph range.
The only way I can think to adjust the kick down is to install a toggle switch that makes the switch active all the time. This is a very common mod and is easily done, the procedure can be found by searching for kickdown bypass.
The other way that might be possible is if you moved the physical placement of the switch, but that might block the throttle from going all the way down negating the purpose of owning a Porsche.
If you do decide to install the byass I will say this, BE CAREFUL. There have been threads of accidents caused by this modification since the kickdown can give a sudden explosion of power. One car was lost to this from a battle with a wet road and a light pole while trying to pass, both got in the way, both won.
If you can place it somewhere visible, most common is next to the handbrake, then this can be more readily avoided if it is something that you can see when get in or look down for another common control.
Hope this answers your question and doesnt scare you too much
.
Lots of people do this mod and have no problem with it, I am just saying that it happens and you should consider all the factors.
Of course the last option is to just get a five speed
.
The only way I can think to adjust the kick down is to install a toggle switch that makes the switch active all the time. This is a very common mod and is easily done, the procedure can be found by searching for kickdown bypass.
The other way that might be possible is if you moved the physical placement of the switch, but that might block the throttle from going all the way down negating the purpose of owning a Porsche.
If you do decide to install the byass I will say this, BE CAREFUL. There have been threads of accidents caused by this modification since the kickdown can give a sudden explosion of power. One car was lost to this from a battle with a wet road and a light pole while trying to pass, both got in the way, both won.
If you can place it somewhere visible, most common is next to the handbrake, then this can be more readily avoided if it is something that you can see when get in or look down for another common control.
Hope this answers your question and doesnt scare you too much
.Lots of people do this mod and have no problem with it, I am just saying that it happens and you should consider all the factors.
Of course the last option is to just get a five speed
.
928 Engine Re-Re-Rebuild Specialist
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From: Brighton, MI
Greg:
I don't think the kickdown itself can be adjust since it's an on/off switch. but you can adjust when shifts occur and how sharp they are. You've got three cables attached to the throttle plate: throttle, cruise (if equipped) and transmission. Try loosening/tightening the tranny cable connection until it shifts the way you like.
You could also install a bypass switch on the kickdown so you can activate it by hand at any RPM instead if just when the pedal is mashed to the floor.
Hope that helps!
I don't think the kickdown itself can be adjust since it's an on/off switch. but you can adjust when shifts occur and how sharp they are. You've got three cables attached to the throttle plate: throttle, cruise (if equipped) and transmission. Try loosening/tightening the tranny cable connection until it shifts the way you like.
You could also install a bypass switch on the kickdown so you can activate it by hand at any RPM instead if just when the pedal is mashed to the floor.
Hope that helps!
Addict
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From: Comox, BC
There are 2 adjustments available on the '86 car. One for shift point (RPM) and one for firmness of shift.
Adjust the shift point first, by adjusting the length of the TV (throttle valve) cable at the throttle quadrant (where the cables meet in the engine compartment).
Then adjust for firmness of shift by adjusting the setting of the modulator valve (the vacuum controlled thing on the left side of the valve body).
Adjust in this order because changing shift-point (rpm) affects shift firmness.
Then, there is a ball on the underside of the gas pedal that you can adjust so that the down-shift switch is activated at the right time..... that is, at WOT.
Adjust the shift point first, by adjusting the length of the TV (throttle valve) cable at the throttle quadrant (where the cables meet in the engine compartment).
Then adjust for firmness of shift by adjusting the setting of the modulator valve (the vacuum controlled thing on the left side of the valve body).
Adjust in this order because changing shift-point (rpm) affects shift firmness.
Then, there is a ball on the underside of the gas pedal that you can adjust so that the down-shift switch is activated at the right time..... that is, at WOT.
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Joined: Jun 2001
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From: Ball Ground, GA
As Brian G implies, the kickdown is not switch operated. The 928 automatic transmission is a pre-computer design, and shifting is controlled by the internal hydraulic control pressure. This pressure is affected by the governor, the valve body, the TV cable, the vacuum modulator, and the kickdown switch.
The TV cable is the primary adjustment. Tighter shifts later.
The kickdown switch is an off-on adjustment thru a solenoid valve. Adding a parallel driver-controlled switch allows you to trick the transmission into thinking that you are at full throttle when you aren't. If you are at full throttle, the switch has no impact. The switch simply makes the transmission more eager to shift down under the control of the TV cable, governor, and valve body, and less eager to shift up.
The vacuum modulator affects the softness of the shifts. It has little affect on the shift points on the 928.
The TV cable is the primary adjustment. Tighter shifts later.
The kickdown switch is an off-on adjustment thru a solenoid valve. Adding a parallel driver-controlled switch allows you to trick the transmission into thinking that you are at full throttle when you aren't. If you are at full throttle, the switch has no impact. The switch simply makes the transmission more eager to shift down under the control of the TV cable, governor, and valve body, and less eager to shift up.
The vacuum modulator affects the softness of the shifts. It has little affect on the shift points on the 928.
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From: Dallas Texas
928SS has some good experience:
all shifts were higher, but 1-2 was noticably higher/now at redline from 4500-5400 before. other shifts at about 6200/a tad over redline but not enough to worry about on this motor, imo and it just seems faster overall as a result, but the track timers will tell the story better than my assometer
two screws are on the govenor body. it pulls out the side of the trans, and you can't miss'em - one on each side/white plastic.
I also did the trans bypass switch, but it only seems to affect shifting under part throttle (ie nicely drops down a gear when activated w/out any additional throttle input), and forces the trans into 1st while moving at low speeds w/no throttle input (impossible to do before).
I've also found some articles that indicated a low rpm shift (assuming everything is adjusted properly) could be from a dirty valve body circut or bad/spring or worn 1st gear clutch packs.
I'm pulling my valve body this weekend to insure it's 100%, and if there's any doubt after that it's going to the place in NY above, just to be sure...
I also found a place that makes HP clutches/stuff for our 722.3 trans http://www.altousa.com/pdf/bulletins/updateBook.pdf#search='mercedes%20722.3%20shifts'
all shifts were higher, but 1-2 was noticably higher/now at redline from 4500-5400 before. other shifts at about 6200/a tad over redline but not enough to worry about on this motor, imo and it just seems faster overall as a result, but the track timers will tell the story better than my assometer
two screws are on the govenor body. it pulls out the side of the trans, and you can't miss'em - one on each side/white plastic.
I also did the trans bypass switch, but it only seems to affect shifting under part throttle (ie nicely drops down a gear when activated w/out any additional throttle input), and forces the trans into 1st while moving at low speeds w/no throttle input (impossible to do before).
I've also found some articles that indicated a low rpm shift (assuming everything is adjusted properly) could be from a dirty valve body circut or bad/spring or worn 1st gear clutch packs.
I'm pulling my valve body this weekend to insure it's 100%, and if there's any doubt after that it's going to the place in NY above, just to be sure...
I also found a place that makes HP clutches/stuff for our 722.3 trans http://www.altousa.com/pdf/bulletins/updateBook.pdf#search='mercedes%20722.3%20shifts'
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Joined: Dec 2002
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From: Australia
My kickdown bypass switch is a momentary, mounted on the top of the left foot rest (under the rubber pad). Initially didnt get the response I wanted, but after a little tightening of the TV cable, it was fine. All I do is tap the switch by rolling foot upwards, and as long as I have enough throttle in, it goes down a gear, and holds it until normal change point for that throttle setting, as though you were accelerating up through the gears from rest, then goes up a gear. Needs no hands or resetting to normal.
jp 83 Euro S AT 50k
jp 83 Euro S AT 50k
