1960s Adjusting the TV rod '61 Deville

[MattG]

My '61 is running great but it seems to not want to down shift.  I read the manual about adjusting the TV rod but some of it I don't get.  Is the dash relay by the carburetor or back by the firewall?  Whatever is by the firewall doesn't seem to move at all with the lever (second pic).  There is also a spring it looks like somebody added that doesn't show up in the manual (first pic).  Does anybody have a cleared explanation of adjusting this?  Normally I would jump right in and try something, but it is running so good I hate to do anything to make worse.
Thanks

[Jeff Rosansky CLC #28373]

If nobody else jumps in, I'm going to say the bottom one with the adjuster on it. Looks like what our 55 has. BUT I don't have that year, so I'm not positive. Does it go down to the transmission?
Someone just added a spring at some point.

[Clewisiii]

The lower is a throttle check valve.

[Gabe Davis]

That is a similar looking setup to my '59. My knowledge is based off of that.

The larger lower rod is the TV that goes down to the transmission. You loosen the two jamb nuts and move it forward or backward. I don't remember which direction affects how the transmission behaves but if you need it to kick down I think it needs to move forward.

The spring is the throttle return spring. It is in a odd place compared to my '59. On mine it runs forward to the oil filter (which was moved to the block in '60) and is attached to the throttle linkage using the hole on the bracket.

It looks like it is effectively doing the same thing as it is below the pivot point. But I'd be curious to know if that was factory. I kind of doubt it.

The smaller upper rod is the linkage that goes to the gas pedal. It runs over to the firewall where it links up to the dashpot and then down and back to the pedal.

The dash pot on the firewall is there to keep the engine from stalling if you get off the throttle very quickly. I had my carb rebuilt by Daytona and the friendly gentleman on the phone explained that those were needed as the idle RPM is so low on these engines (my non air 59' is 450) that the engine can stall when you quickly let off of the throttle. The little button is vacuum activated and pushes out when there is high vacuum and slowly lets the throttle back down to idle.

It looks like yours is an AC car as you have the idle up relay up top to bring the RPM up when the compressor kicks on.

[Big Fins]

First, get rid of the spring. It is incorrect. Someone put it there to return the throttle back to idle because they didn't know how to set the base adjustments. It should go behind a small hook of sorts on the throttle linkage at the carb and attach to a fitting with a hole in it held by the right rear bolt in the thermostat housing as you are looking at it from the front of the car. The long straight shank is toward the front of the car too.

That rod the spring is hooked to is the TV (Throttle Valve) rod. When the car is off you should be able to remove the nut holding the adjusting trunion onto the throttle linkage and it should be able to slip in and out of the trunion not snapping forward or back. Loosen the jamb nuts so that is possible. This is the base TV rod setting. The trunion slips back and forth, it is not threaded.

The dashpot on the firewall is as noted above. An anti stalling device that has a vacuum hose attached to the rear of it so that the plunger retracts slowly.

The throttle linkage is mounted on the firewall and a 1/4" drill bit is used to set the base setting on that. This also adjust the accelerator pedal at the same time for optimum throttle travel. From there you have to adjust the linkage on the carburetor so that like the TV rod, it attaches with no forward or rear movement. It should be held in by a Cotter pin with a flat washer. Now you have to set the base idle and air/fuel mixture.

When you have the TV rod off of the carb, move it forward and backward to be sure it's not sticking or binding. Sticking could be in the valve body of the transmission due to worn out or burned fluid. Reattach the trunion to the carb and run the forward nut back and the rear nut up until both contact the trunion and without moving it.

Now go for a test ride. Shifting 1-2 is seamless. 2-3 you may feel the shift but it shouldn't be harsh or jerky. 3-4 is also a fairly seamless shift. You are going to be stopping to adjust the trunion many times until that 2-3 shift is smooth.

To make the adjustments, move the trunion only a quarter turn on the jam nuts each time. You'll need 2, 7/16 open end wrenches. This makes the TV rod longer or shorter and the increments of the adjustment are very small to perfect the shift. I say small, meaning you are moving the trunion about 1mm in either direction. Write down which way you are moving it and how many moves, so you can get it back to a base point if you need to start over and go the other way.

This is going to take time and sweat because you are constantly taking off the air cleaner and working over the now very hot engine. Keep rereading the manual until you understand exactly what it's telling you. The exact sequence is there, you just have to understand it.

[David King (kz78hy)]

Very small moves on the nut change how it shifts.