Th350
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Heel & Toe
Joined: Dec 2020
Posts: 18
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From: barnsley england
Th350
Corvette 1978 pace
Kick down cable disconnected
The th350 doesn’t have to have it connected and no it will not harm the box , th400 that’s a throttle valve and that needs a cable fitted , th350 different animal.
Right can any one tell me and no guesses if you don’t know please don’t comment,
When driving say coming out of a rounderbout when the car is in as the modulator has changed up into 3rd as the pace car has a 3.55 diff so it’s low geared not like the anniversary of the same year. Which has a 3.08 which is long legged compared,putting the accerator half way down the car changes down and when the revs rise it changes back into 3rd bearing in mind this was not wot (wide open throttle )
When it does this if I put it manually in second when it has changed down on its own it sort of goes into a solid second and runs up till you snick it into third,is it meant to do this change down and is it the modulator that does this , is it the vacuum decreasing that causes the modulator to down shift , the governor’s responsible for changing when the revs rise as opening the throttle decreases manifold vacuum so the modulator becomes ineffective,
Should it change down mid throttle without the kick down cable? What do you think
Kick down cable disconnected
The th350 doesn’t have to have it connected and no it will not harm the box , th400 that’s a throttle valve and that needs a cable fitted , th350 different animal.
Right can any one tell me and no guesses if you don’t know please don’t comment,
When driving say coming out of a rounderbout when the car is in as the modulator has changed up into 3rd as the pace car has a 3.55 diff so it’s low geared not like the anniversary of the same year. Which has a 3.08 which is long legged compared,putting the accerator half way down the car changes down and when the revs rise it changes back into 3rd bearing in mind this was not wot (wide open throttle )
When it does this if I put it manually in second when it has changed down on its own it sort of goes into a solid second and runs up till you snick it into third,is it meant to do this change down and is it the modulator that does this , is it the vacuum decreasing that causes the modulator to down shift , the governor’s responsible for changing when the revs rise as opening the throttle decreases manifold vacuum so the modulator becomes ineffective,
Should it change down mid throttle without the kick down cable? What do you think
Drifting
Joined: Aug 2019
Posts: 1,510
Likes: 498
First off why would you not have the Kickdown cable connected ? It’s a Boost circuit that’s all part of the equation.
second thing , Vacuum Modulator controls pump pressure and that’s it . High vacuum low throttle situations call for the Pump to relax , high throttle low vacuum situations call for max pressure to prevent clutch slipping and the Modulator does this . Of course pump pressure has an effect on the equation and is tune able through the vacuum modulator to allow easy cruising not to hunt for a gear or down shift in light throttle situations
The Governor is controlled by the rotation of the out put shaft and fluid line pressure of the valve body in order to shift up , faster you go centrifugal weights move an internal valve to gain strength against the line pressure, that’s what Governor’s like to do is shift up , line pressure from the valve body (controlled by the pump/vacuum modulator and kick down switch ) try to keep it from shifting too early
Everything is fighting for control of the actual shift valve , Pump pressure controlled by the vacuum modulator, the Governor, the Kick down switch all have to be in tune with each other to move the shift valve inside the valve body to shift right or correctly under all circumstances
to answer your questions I have no idea what you are asking but maybe now you’ll understand more the basic functions of what’s going on inside the “ box” that may in courage you to do more research
second thing , Vacuum Modulator controls pump pressure and that’s it . High vacuum low throttle situations call for the Pump to relax , high throttle low vacuum situations call for max pressure to prevent clutch slipping and the Modulator does this . Of course pump pressure has an effect on the equation and is tune able through the vacuum modulator to allow easy cruising not to hunt for a gear or down shift in light throttle situations
The Governor is controlled by the rotation of the out put shaft and fluid line pressure of the valve body in order to shift up , faster you go centrifugal weights move an internal valve to gain strength against the line pressure, that’s what Governor’s like to do is shift up , line pressure from the valve body (controlled by the pump/vacuum modulator and kick down switch ) try to keep it from shifting too early
Everything is fighting for control of the actual shift valve , Pump pressure controlled by the vacuum modulator, the Governor, the Kick down switch all have to be in tune with each other to move the shift valve inside the valve body to shift right or correctly under all circumstances
to answer your questions I have no idea what you are asking but maybe now you’ll understand more the basic functions of what’s going on inside the “ box” that may in courage you to do more research
Last edited by Eric P; Aug 28, 2021 at 05:54 PM.
