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Discussion Starter · #1 ·
Hey guy's & girls,
Last year my tranny was completely rebuilt at a professional shop. I was told that there is no kick down lever on my particular trans. I have also noticed since day one that when driving under normal conditions, it will shift from 1st to 2nd almost immediately after takeoff. It does not build up any RPMs. Sometimes it will shift right through to third all in one shift. Could this be a module problem? When I hit the accelorator it shifts out normal, building up the RPMs before shifting. (Yes it does chirp 2nd gear). When I brought it in for the 500 mile inspection the mechanic said the module and vacume pressure were fine and had no answer for the shifting problem.
Any suggestions would be greatly appreciated.

Thanks

289, c-4 trans
Edelbrock performer RPM
Holley 600 cfm w/vacume secondary
Compitition RV cam
MSD Ignition
3:55 gears
 

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Hello.:) As far as the 'shifting funny' thing goes, that is very often a modulator problem. A new one is cheap and is very easy to install. I would also check the vacuum line going to it to see if it had any 'issues'. A C4 transmission had a kick-down linkage when it was new. That linkage might be missing from your car, but it is supposed to have it. The linkages were a little different for different year models, but they all had one. Hope that helps.:)
 

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Discussion Starter · #3 ·
Thanks veronica,
I was told that my trans was a manuel type valve body and did not have a kick down cable. I don't think that is correct though. I will check for one and try installing myself. The vacuum line/hoses are new and the modulator I was told was in good shape. I'll change it anyway since it's a cheap fix. Hopefully that will solve my problem.

:thanks:
 

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First thing to do is to make sure that there is no vacuum leak or excessive lengths of rubber line (Which can collapse and cut off the available vacuum signal) to the modulator valve. There is an adjustment on the mod. valve through the hose nipple. By adjusting you can increase the duration of the shift point between gears. The range of adjustment on the modulator is plus or minus 200 or so RPM between shifts. You should have hard line plumbed between the vacuum source and mod. valve with small sections of hose for connecting the ends. There is a molded 90 degree hose that is for the mod. valve connection. The pre-bent hard line and molded hose are available from resto vendors.

The kickdown lever is available from National Parts Depot as well as the return spring and bracket that goes with it. The cable too, as well as the above mentioned hard line and hose.

On the 66 model trans if you place the gear selector in the second notch down from neutral, the trans starts out in second and then up to third. You will not get first gear in that position. Possibly you also have a shifter adjustment needed.
 

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Discussion Starter · #5 ·
Thanks for the info.
Well I checked and do see a cable kickdown, however, It has some wear to it. Some of the strands of cable have broken away and all is left is a very thin stran. I'm going to change that first and adjust it. I noticed that when I push the pedal all the way the kick down cable is not engaging far enough. I will also try adjusting the modulator. The vacuum lines appear to be good and not bent or collapsed. Do you know of any other auto part stores that may carry the kick down cable?

Thanks again
 
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