1965 Straight 6 Automatic Transmission Torque Converter Issue
 

I am new to the site and look forward to learning and sharing.

I recently bought a tired, but complete 1965 I-6 with the automatic transmission. The car runs/ran great when I first bought it, save for a minor shudder when the car was in gear and I had the brake applied. The shudder varied at acceleration, but completely vanished when going downhill and foot off gas.

The shudder started getting worse, and began to happen even when the car was in "Park." On top of that, when I put the car in "Drive" with the brake applied, the motor almost died. In "Reverse," it completely died. It felt like the motor was way out of balance. I even put the car up on jackstands and it still happened.

I checked the timing, vaccum system, modulator vacuum hose, mounts etc, all OK. I suspected the torque converter was at issue, even though the lockup/ disengage was OK. I replaced the harmonic balancer for good measure-no change.

Last night, I completely drained the trans and torque converter of all fluid: the shudder vanished. The only issue is a faint vibration that can be felt if you put your hand on the valve cover of the motor at idle, and in "Park." I'm convinced it's the converter, as the shudder is gone with an empty converter.

Any thoughts, suggestions? I did notice the old fluid was dark brown and smelled burnt. Thanks

When was the "tried and true" last run? Sounds like you have picked up a lot of varnish and deposited in the carb. You probably need to clean the tank and rebuild the carb, Also the fuel pump may need to be rebuilt. I would also change the transmission and converter fluid and filter.

its not a converter, if it "shudders in park" you are most likely feeling an engine miss fire