Does anyone know where I could find a kickdown cable for a 1969 TH-350 setup...or do I have to use some kind of universal cable? Thanks, Dan
Only thing I can think of is stopping by a local tranny shop and seeing if they have any. I don't know if Buick's are specific to Buicks cause I've never seen more than one at a time and its so infrequent that I see cable from other makes.
I wondered about this as well when i did my ST300 to TH350 swap along with the 350 to 455 swap. I found with a BBB it was not needed (more than enough power)and i never looked into it again, if i need the downshift i just do it manually. Everything else works as it should.
I had luck ordering straight from parts of a local buick dealership although that was 6 years ago. Had it next day. Later Greg
Did you try NAPA, AutoZone, Advance, etc.? That's a pretty generic part. I got one from A.Z. several years back for my V6 w/TH350. It was like 20 something bucks.
Greg, That cable does more than direct a downshift. In order for the trans to shift correctly, it needs 3 inputs. 1) vacuum to the modulator(engine load). 2) governor signal (road speed). 3) detent cable input(throttle position) Without the cable, the trans will typically short shift and the the line pressure may not be optimal for the shift. Shifting manually is a way around this, but you may be harming the trans by doing this. I know on the 400, shifting 2-3 manually will eventually wear a band in the trans causing problems. I don't know if this is also true of the 350. Of course your transmission might be built for manual shifting, and all of the above will not apply. IMHO, it's much better if you set the trans up to do what you want, when you want it. One less thing to worry about in a race or street encounter situation:grin:
I had the same problem this year. The kickdown goes from the gas pedal straight to the tranny on my 71. Most th350 go from the carb to the tranny. I bought a b+m universal kit and made some mods. Works fine. This is before I found that C.A.R.S. carries them. Good luck.
I just switched my '72 Skylark from a TH350 to a 200-4r so I have an extra kickdown cable that I should be able to spare. If you can't find one, send me a PM and I should be able to hook you up.
Larry thanks for the great info. the car does short shift but i thought the 4200RPM stahl convertor was the cause. I do let it up shift by itself in normal street driving and manually shift at the strip or any other full throttle fun times. driveabilty is fine as is for me as long as the trans is not being hurt. thanks for letting us know this as i would have hated to misinformed anyone and caused them problems. good news is i dont have to correct it because the slush box is comming out and a Muncie is going in.
I'm no transmission expert, but I believe that the ralationship between a cable and shift points only applies to TV cables, like a 200R4 or a Torqueflite, and not a downshift cable, like a TH 350. The function performed by the TV cable in those transmissions is performed by the vacuum modulator in a trans that has one. If your TH350 is short shifting, adjust the modulator.
Nick, The detent cable definitely affects the shift points and shift feel. The modulator only adjusts minimum throttle shift points,and feel, and the adjustability is 2-3 MPH at most. If you do not have a detent cable installed and adjusted, it will cause the trannsmission to short shift. This is because the detent valve is in the closed throttle position, and it is telling the transmission the throttle is closed even when your foot is on the floor. The same thing happens in the 400 if the electrical kickdown is not hooked up or defective, it shortshifts. The transmission valve body determines the correct shift points for a variety of conditions according to engine load(modulator), governor(speed), and detent(throttle position) signals. Without all 3, the trans won't shift correctly. The TV cable on a 200R4 is critical. If you don't have that right, you can ruin a good transmission in a hurry. That is one reason I dislike the later GM transmissions. When the time comes, I'm going with the GVO for my GS.
Larry I'm not disputing your knowledge, but how can this apply to a TH400? Isn't the electric kickdown an on/off switch? That wouldn't give the transmission throtle position, but only tell it when it is at full throtle.
Nick, The electrical switch for the 400, actually passes the 12 volts to the detent solenoid before full throttle if it is adjusted correctly. The trans will either downshift or not depending on the other 2 inputs, modulator, and governor signals. On the 400, no detent hookup, it will short shift, trust me on this, I'm sure. I'm no expert either, but I've talked with enough experts(like dcm422 on this BB) to know
The kickdown switch on a th400 works a bit differently than the cable on a th350. It is connected to a solenoid that exhausts oil to the detent valve in the valve body which causes the trans to kickdown. The cable on the th350 is directly attached to the detent valve and (along with vacuum) sets the shift points. Once full throttle is reached, the detent valve is bottomed and the trans kickdowns. Unlike the th200 or 200 4R, you can run a th350 without the cable as the cable doesn't drastically affect trans pressure. The TV cable on the 200's takes the place of the vacuum modulator and you will cause trans damage if you run without it. In the case of the th400, when the trans is in kickdown, detent oil is also directed to the pressure regulator valve to increase trans pressure. Running without the kickdown hooked up will not damage the trans. It will short shift at full throttle and not shift as firm. I would have to check the flow of detent oil on the th350, but my guess is that the same principle applies and oil is directed to increase shift firmness as well. Years ago, a well know individual on this board (you know who you are! :Brow: ) ran his th400 without the kickdown hooked up and just manually downshifted it when he was street racing. "I Just pull first and punch it!" It worked good for a while until I got a call that the trans wouldn't go into reverse. :eek2: By manually shifting into first, the rear band would come on and engage. It does not do that when in kickdown. The excessive use caused the band to wear out and would no longer apply when put in reverse. So...........Rebuild time! :ball: A similar thing can happen when upshifting from 1-2. The intermediate band will come on and can burn out. While it may be time consuming (or a pain in the neck) to hook up either kickdown switch or cable, the factory would not have spent the money to design these items as "extras". They are needed to have the trans function properly. This is just my opinion on this, and others may disagree. Hope this helps, Mark DeConti
Get a new cable! B&M has a "Universal" TH350 Kickdown cable at your local auto parts store for $35. It has a connector to hook it up to the carb/throttle, but I just cut that end off, leaving the cable end itself, so you can run it through the firewall to your gas pedal, for original function.:Smarty: :TU:
Driver2, How did you connect the gas pedal side? I believe there was an adjustable piece attched to cable on original aetup right? You wouldn't happen to know the PN for that would you? I looked on B&M website and didn't find anything. Thanks, Dan
