49 Shift Problems - TV Rod Adjustment?

[FabCad]

I just put a new carb on my 49 and the hydramatic won't shift properly now. It must be something with the TV rod/throttle linkage because it was shifting just fine before. I tried adjusting the TV rod several times - but no luck. The trans shifts into 2nd gear smoothly. But it won't shift into 3rd easily. It just hangs in 2nd gear as I accelerate. But once I take my foot off the gas - just slightly - it slams into 3rd gear.

Any advice on how to set up the linkage properly?

Thanks.

[FabCad]

Did the procedure in the shop manual, and read several old forum posts here, but still no luck. It seems like the longer I make the TV rod, the sooner it shifts. But the trunion is now at the end of the TV rod. And it still won't shift into 3rd gear. It holds 2nd gear as I accelerate. It's only when I let off the gas a little that it finally slams into 3rd.

[dadscad]

Is the new carburetor identical to the old one? Compare the new to old linkage plate where the throttle rod and TV rod connect. Be sure the holes move in the exact same arc. If the TV rod isn't pulled in the proper ratio, the transmission will misbehave. Did the TV rod become disconnected from the transmission lever?

For my 63, when I tried to purchase a rebuilt carter, the new one didn't have the adapter plate on it for the TV rod. I had to take it off the original carb and put it on the new rebuilt one. Could that be your situation, also?

HTH, David

[FabCad]

There's a 53 motor in my 49 Cad. But the previous owner was using the 49 2bbl intake/carb setup. I reverted back to the 53 4bbl intake/carb. As far as I can tell the carb linkage is identical. And I confirmed the TV rod is hooked up at the transmission properly.

[dadscad]

I would think, the centerline of the 4 bbl carburetor primary shaft and TV trunion mounting hole would have to be in the exact same position of the 2 bbl carburetor, when mounted on the engine, for that to work. I take it your transmission and TV rod are original to the 2 bbl design. If the 4 bbl primary shaft center, is physically farther forward on the engine, than the 2 bbl carburetor, that would require the TV rod to be longer. Were there different length TV rods for 2 bbl and 4 bbl configuration?

[FabCad]

That's a great question... I don't know if the TV rods were different lengths for 2 vs. 4 bbl setups. I don't have the other TV rod - only what was on the car with the 2bbl setup.

[dadscad]

If you still have the 2 bbl manifold and carburetor, measure from the same reference point on the 2 & 4 bbl manifold to the trunion pivot hole on the respective carburetor. If the pivot locations are not positioned identicly in location, there would have to be one of two solutions, either enough adjustment to accommodate both 2 & 4 bbl set ups or two different TV rods. In my minds eye, I think the 4 bbl TV rod pivot will be farther forward on the engine than the 2 bbl will be. I suspect the 4 bbl set up will require a longer TV rod.

HTH, David

[Matt Innocenzi]

Just a thought - what if you temporarily disconnect the TV rod and drive the vehicle?  This way it will isolate the problem and tell you for sure if it is the TV rod and not some other adjustment inside the transmission.  I had a similar problem and the fine folks on the forum suggested that and it helped me isolate for certain it was a mal-adjusted TV rod.

Matt

[FabCad]

I measured the distance from the manifold back mounting hole to the trunion pivot hole on each set up. It is the same distance for both.

One thing I did notice is the pivot arc of the carb linkage is a bit different -- the 2bbl carb seems to pivot at a steeper arc.

I not yet attempted to drive the car with the TV rod completely disconnected.

[Jeff Maltby 4194]

49 off firewall linkage.