65 Riviera kick down switch check/fix

[Kahuna28]

Hello all,

I can't seem to find the way to check to see if my kick down switch is working. I seem to remember someone here talking about an article in the Riview about this, but I can't find the post. I am a ROA member and I have the cd of back issues but it doesn't look to be on there. It may be from a more current issue, anyone know where I should look? More importantly I need to get this working so I need to troubleshoot it...

I think the switch is working (not 100% sure but it checked out with a meter), but I don't know where to go from there.. Any suggestions or directions to find this article would be greatly appreciated..

[RivNut]

With the ignition switch on but the car not running, crawl under the car and take your good ol' mechanics stethoscope with you. Have someone depress the kickdown switch and while holding the stethoscope against the body of the transmission. You should be able to hear the actuating mechanism inside the transmission engage and disengage.

[Kahuna28]

Thanx Rivnut,

I did what you said and we could not hear any noise from the trans. Does that suggest the switch is not working or is it a connection issue? What would be the next step?

Thanx,
Aaron

[RivNut]

Take a test lamp and start checking to see where you have power and where you don't. Power to the kick down switch comes from the same fuse that is connected to the windshield wipers - from my recollection, it's a yellow wire that goes to the switch. Start at the fuse box and see how far you get before you no longer have any power.

Ed

[gungeey]

Hey Kahuna...1st of all, always have the OTHER GUY crawl underneath the car for the test...HAHA.
Check your wire heading down the backside of the engine block for breakage...the heat does a number on them over the years.. Stev

[rgfullerton]

Hello all,

I can't seem to find the way to check to see if my kick down switch is working. I seem to remember someone here talking about an article in the Riview about this, but I can't find the post. I am a ROA member and I have the cd of back issues but it doesn't look to be on there. It may be from a more current issue, anyone know where I should look? More importantly I need to get this working so I need to troubleshoot it...

I think the switch is working (not 100% sure but it checked out with a meter), but I don't know where to go from there.. Any suggestions or directions to find this article would be greatly appreciated..

THe "KICK-DOWN" switch is not a Kick Down. This is the OLD Kennedy-Bell Buick race team secret !! This is actually a TORQUE CONVERTER switch pitch. Its like having a high stall torque converter "ON DEMAND". I don't think you would ber able to hear it. KB would put a switch right on the transmission shift for MANUAL control.

[RivNut]

The Kick-down feature and the Switch Pitch feature are both controlled by the same switch. There are two wires running from the switch to the sending unit on the side of the transmission. The sending unit has two male terminals on it. The horizontal terminal is the switch pitch terminal, the vertical terminal is the kick-down terminal. You can hear the solenoid inside the transmission switch the vanes in the torque converter with a mechanics stethoscope placed on the body of the transmission. (Engine off, ignition on)

65-67 TH400's are the only TH400's (Buick just called it a ST400 to continue use of the word turbine) to have "switch" (change) the "pitch" (angle) of the vanes in the converter of these transmissions. All other TH400's continued to use the electrically activated kick-downs up through the 90's when everything became electronically controlled (the TH400 then became the 480LE.)

If you'd like for me to, I'll be happy to make a PDF file of page 74-88 in the '66 Chassis manual which fully describes how the 12V "switch attached to the throttle linkage" and "solenoid on the transmission" are used to "kick" the transmission "down" a gear for "better acceleration for speeds under 70 mph" and post it here.

Ed

[lenmann]

Ed, not sure about the OP but I would like it if ou would post teh manual page describing the operation of the SP trans.

Thansk,

Len.

[RivNut]

Linda and I are waiting for my grandson to arrive so we can leave for a spring break vacation. I'll be back next Saturday and post the picture of the page for you. In the mean time, try "googling" switch pitch ST400 and see what you find

Ed

[Kahuna28]

Ed, yes please.. I got pulled on another project, but I will be back on it shortly. The more info the better.

Thanx,
Aaron

[Wildcat65]

The switch is on the same circuit with the wipers- just a reminder to check the fuse - previous post about checking for 12v power is right on it. (insert story here)

I've taken the switch apart to clean and lube, that helped mine a lot.
I can hear the solenoid click without the stethescope

[Ron Luchene]

For the sake of future searches on this topic I decided to place my question here rather than start a new thread.

The down shift on acceleration has never functioned on my car. I recently completed several adjustments after my carburetor rebuild and out of no where the other day the transmission kicked down on full throttle. Great news I thought and than I realized the car was now stuck in 2nd gear. I was able to limp it home by shifting manually but after a few miles I couldn't get it to go into 3rd gear.

I checked all of the connections today and adjusted the detent and stator switches as discussed in the manual. The car shifts automatically through all gears but again it will not kick down. A few questions...

1. I noticed a lot of play in the linkage where the detent switch is mounted. I assume this is not normal and needs to be corrected. Any advice? Are there bushings available or do I just need to visit my local Lowes store and find something that will work?

2. I am confused as to how the detent switch would open upon full acceleration. Is the cam it rides on flat on one side?

3. With regard to the connector at the transmission, I have 12v on one wire at all times and the other has 12v on full acceleration. The solenoid functions on full acceleration so it appears to be okay. My question is why I have two wires coming to the transmission but only one hooks up to anything. Do I have a newer style switch or the wrong switch?

Sorry for so many questions but I do not know a lot about transmissions and would love to learn how this is suppose to function. The transmission was rebuilt before I bought the car and seems to function normal in all other ways. I appreciate any assistance.

Thanks!

Ron

[RivNut]

Two wires to the transmission: One if for the kick down, the other is for the varible pitch torque converter. The horizontal terminal is for the variable pitch converter, the vertical terminal is for the kickdown.

I have switches for a '64 and a '66 but not one for a '65, therefore I don't know which style it is. The variable pitch also has a switch on the brake pedal that puts the converter in the high stall mode when the car is at idle with the brake on. Buick used this feature to keep the car from creeping when at a stop using less brake pedal pressure.

Find a copy of a '65 wiring diagram and see what you can figure out.

If the car is not upshifting that's a function of the vacuum modulator. Check the vacuum line from the passenger's side of the transmission to the base of the carburetor. Look for cracks or breaks in the rubber line or it might be just as easy to put a new vacuum hose on it.

Ed

[Ron Luchene]

Ed,

Thanks for the reply. Since the transmission was rebuilt before I bought the car and I only have one terminal on the switch at the side of the transmission, I thought it might be best to figure out which transmission I have. The tag has the following information on it:

BR 66 112198. 442 is stamped above these numbers.

I assume the year code is 66. Is this still a variable pitch transmission? If so, I assume I need to drop the pan to see if the wire for the variable pitch is laying inside the trans body. Is it possible they would be trying to drive control for both kick down and variable pitch from a single wire? There is only a connection for kick down on the switch at the side of the transmission even though the connector coming from the carb has both wires present.

Also, can you explain how the detent and stator switches work in conjunction with each other in layman's terms? Is the play in the linkage at the location of the detent switch normal?

Sorry for all the questions!

Ron

[RivNut]

I have no idea why there would be only one terminal on a '66 transmission. Someone has done something that's not kosher.

If I were you, my next step would be to visit a reputable transmission shop and see if they can help you. There are other ways to identify a variable pitch transmission besides the terminal. The pan will look like someone stomped on it really hard from the inside and left a heel print on the bottom of the pan (fluid pick up area.) There are three dimples on it as well. To identify it further would require that you drop the transmission and look at the input shaft on the transmission. Look around on google for images of other "switch pitch" transmissions and see what you can dig up.

Ed

[Ron Luchene]

Definitely a variable pitch pan by your description. I guess I will drop the pan and see what is lurking on the inside. Would the transmission function without the variable pitch wired up?

[RivNut]

Yes, it will function just like any TH400 that Chevy built or any TH(ST)400 that Buick built starting in '68. Rumor has it that the variable pitch function was removed by the bean counters (additional expense that wasn't necessary.)

The performance guys like it because the variable pitch converter will allow the engine to reach a higher rpm before the stall speed of the converter over powers the brakes. You can power brake the engine for more RPM's for a quicker launch when drag racing. I doubt if that was Buick's use for it though.

Ed