Originally Posted by Transman
Originally Posted by TimS
Have been working on various vibration issues with my 72 Roadrunner, 400, 727 car. I have one with the motor from around 1000 to 1200 rpm or so while the car sits. So pronounced that the steering wheel and dash vibrate quite a bit. Doesn’t do this at idle around 800 rpm or when you get in the 1300/1400 range. I unhooked the alternator, fan and power steering belts. Still have it. I noticed the crank pulley is pretty wobbly. Bad crank pulley cause this issue or does it sound more like a bad damper?

Thanks.


When did the vibration start?

Always there since the engine was built or did it start on it’s own or ?

If from day one realize that a normal 400 is externally balanced - meaning it takes a special damper and converter or flywheel.


Previous 30+ years owner isn’t sure when it started but that it’s been there for quite some time.

The damper on the motor does have a good size weight on it. Previous owner did have the motor rebuilt over 25 years ago but couldn’t recall if the vibration has been there that long or not.

What is special about the torque converter and flyweel?

1968 Barracuda Fastback 318-2BBL 904 2.76 Frost Blue Survivor
1970 Roadrunner 440+6 BBL 727 AT 4.10 SG Dana Blue Fire Metallic
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1972 Barracuda 318-2 BBL 904 AT 3.23 1 Legger Tor Red/White Vinyl Top
2007 Dodge Ram 1500 5.7 Hemi AT Patriot Blue
2011 Dodge Challenger RT 5.7 Hemi 6spd 392 SG Triple Black
2014 Dodge Charger RT Max AWD 5.7 Hemi AT 305 Billet Silver