Late shift/strange kickdown adjustment (940)

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Old 03-13-2014, 06:11 PM
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Default Late shift/strange kickdown adjustment (940)

My 1995 volvo 940 is shifting late (1st-2nd at 3500 rpm and 2nd-3rd at 3800 only if i let off the gas). I have tried to readjust the kick-down cable while following the instructions in my Haynes service manual. The instructions in this manual explain the cable to be able to have "50.4-52.6mm of space between the crimped stop to the adjuster sleeve" when the throttle is at full throttle. This is not achieved. Furthermore, when I pull the kick-down cable by hand, it only extends 1.35inches (34.29mm). Needless to say, I can never achieve the 50+mm of cable movement, nor can I achieve full throttle when the cable is installed on the throttle spool due to the fact that the kick-down cable is restricting it. Additionally, when the kick-down cable is removed, the transmission still shifts a little late (3000 rpm-ish), but it shifts on its own (without me letting off of the pedal). Is my Haynes manual wrong? This is the original cable and has been working fine for years. Could it have possibly fouled itself inside the transmission? i should also mention that I have recently removed the transmission to replace the rear main seal, but the issue was occurring before this. Any help is appreciated.

thanks
 
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Old 03-14-2014, 01:04 AM
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sounds like you're overdue for a new cable. i had to replace mine (1992 volvo 740T with 230k miles) last summer.

anything that puts pressure on the cable, like routing it so its got extra bends will mess it up.

the south end of that cable is INSIDE the transmission.
 
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Old 03-14-2014, 11:55 AM
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how do you explain the late shift when the cable is removed? I have checked the routing of the cable and it is routed clear of bends, etc. The transmission shift points had been desirable until one day it started shifting late. What would have changed with the cable?
 
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Old 03-14-2014, 12:45 PM
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its jamming partway out so its thinking the engine is under high throttle, which delays upshifts
 
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Old 03-14-2014, 06:07 PM
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I understand the concept of the kick-down cable. But I don't understand what could be restricting the cable from being pulled out further than 30mm... The cable easily moves out and returns the crimped marker to the adjustment housing. I have disconnected the cable and have moved all around, even getting it to be at a straight shot, there never is extra slack in the cable...

Thanks for all of the help
 
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Old 03-14-2014, 06:30 PM
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the cable could be broken inside and partly stretched, although I'd expect it to have a high resistance if this was the case.

something could be broken inside your transmission, that will get more expensive.

when you pull that cable out, about 1/2" before its fully extended, it hits a 'cam', which gives additional resistance til you pull past it. you can feel this on the gas pedal, before the pedal hits the floor, there's a resistance, step harder, and pushes through it. this cam is in the gearbox, and is the kickdown. ok, I just checked mine, I hit the cam at about 2" pulled out from the orange cap, then when it clicks, there's about another 1/4 or 1/2". my measurements aren't exact as the crimp seems to be missing from my new cable.
 
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Old 03-14-2014, 07:13 PM
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yea i feel the 'cam' resistance, and am able to move past that "click"/notch in the cam. But I cannot reach 2 inches of movement.
 
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Old 03-14-2014, 11:04 PM
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when the throttle is at idle, the little bead on the wire is just 1-2mm past the orange dust cap on the end of the ferrule, with no slack in the wire ?
 
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Old 03-14-2014, 11:54 PM
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correct
 
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Old 03-15-2014, 12:14 AM
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then it sounds like something is hanging up in the transmission side. pulling and repairing a transmission is expensive at a shop and fairly advanced mechanics..

assuming the car is a keeper, a used AW70/71 tranny out of a parts car may be your best bet. AW71 is a heavy duty version in the later 740 and all 940 turbos. regular NA 240 and 7/9 got the AW70. they are pretty much interchangeable. that and finding someone to help you change it on the cheap.
 
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Old 07-08-2014, 01:51 PM
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update: i've been dealing with other projects and have had this on the back-burner. With the kick down cable removed, I am getting better shifts but they are still late. I do not have to let off of the gas to go from 2nd to 3rd if the kick down is removed. I recently read that a faulty TPS could impact the transmission's shifting. I tested my TPS with a voltmeter and was getting some strange readings. Idle shows 11.5v and as i press the throttle the volt reading jumps all around, and is never a consistent increase or decrease. The car runs great and the tach doesn't bounce around. Could the TPS affect my vehicle's shift points?

Again, this is a 1995 940
 
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Old 07-08-2014, 02:33 PM
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the only throttle position sensor on an LH car is a microswitch for idle, and another for full throttle, there's no potentiometer there, its just a switch closure.

and none of that is connected to the transmission. the AW7x transmissions are purely hydraulic with the only external input the throttle pressure cable (and the OD/4th enabled solenoid)
 
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Old 07-08-2014, 02:38 PM
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Volvonator, this is quite DIY doable: drop the transmission pan, the cable's spool is right there, no big deal... May be the cable is off the spool there which would cause a restriction. Helps to do it on a lift.
 
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Old 07-08-2014, 08:45 PM
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I have dropped the pan on a lift and the cable, spool, and cam of the kickdown all seem to be functioning correctly.
 
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Old 07-08-2014, 10:09 PM
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Well then, get a new cable and all should be well... Not that much else to it.
 
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Old 07-09-2014, 12:41 AM
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unless the problem is internal in the transmission and/or valving.
 
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Old 07-09-2014, 11:20 AM
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which is what i am thinking it is. The main reason for this is because the shifts are still late even with the kickdown removed. Additionally the kickdown is not at the point of "cam" resistance, and therefore i don't believe it is preventing the transmission from functioning properly in any way.
 
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Old 07-09-2014, 12:09 PM
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Which could be. However, at this point I'd think that a new cable would be a good investment to eliminate it as a possibility before digging into the costly process of more involved transmission repair.
BTW, How many miles on this car? What did the fluid look like?
Any transmission history available, fluid changes, etc?
 
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