Vibration??
Don't mean to push the thread up but I am having a similar issue.
I just acquired a '74 Dart Custom 4-door with a 225 (160K miles) and it starts and runs in P/N just fine (it's blowing some oil into the air cleaner, but that appears to be an unrelated issue) Plugs are all a nice brown, and dry compression came in at 155-165 on all 6. Not sucking air through the tail and no vacuum leaks on the 1-lunger.
However, once in gear is vibrates...the antenna & anything of any length starts wobbling.
When I start off from a dead stop and accelerate hard, I get a good shuddering that disappears when the torque comes off or when it shifts into 2nd, whichever comes first. I had them replace the left motor mount insulator when new exhaust was installed, the tranny mount seemed solid (if I grab the driveshaft with 2-hands and shake it, I can get a little movement); likewise the right mount appeared blameless...
If I rev the motor fairly hard in Park, I hear a train of light knocking, can't tell if it's top end, cam, or crank. I just adjusted the valves today, no change. In gear with the parking brake hard set, there is some lifting of the block at the (new) mount on acceleration, maybe 1/4", which seems normal.
If the car is driven gently, there's no issue except when standing at a light...my son has taking to throwing it in Park because it is so annoying.
I'm guessing that the engine is fairly worn and I'm getting some blowback but that won't cause this...I have a trans mount and can get a right motor mount...reading around about harmonic balancer issues, but it doesn't show up at speed. I've had U-joint issues with previous Mopars ('65 Fury/383, 83 Ram conversion van, 318, both 727s) and this does not feel like that did (which was more of a fine vibration when accelerating at speed).
Thanks
Don't mean to push the thread up but I am having a similar issue.
I just acquired a '74 Dart Custom 4-door with a 225 (160K miles) and it starts and runs in P/N just fine (it's blowing some oil into the air cleaner, but that appears to be an unrelated issue) Plugs are all a nice brown, and dry compression came in at 155-165 on all 6. Not sucking air through the tail and no vacuum leaks on the 1-lunger.
However, once in gear is vibrates...the antenna & anything of any length starts wobbling.
When I start off from a dead stop and accelerate hard, I get a good shuddering that disappears when the torque comes off or when it shifts into 2nd, whichever comes first. I had them replace the left motor mount insulator when new exhaust was installed, the tranny mount seemed solid (if I grab the driveshaft with 2-hands and shake it, I can get a little movement); likewise the right mount appeared blameless...
If I rev the motor fairly hard in Park, I hear a train of light knocking, can't tell if it's top end, cam, or crank. I just adjusted the valves today, no change. In gear with the parking brake hard set, there is some lifting of the block at the (new) mount on acceleration, maybe 1/4", which seems normal.
If the car is driven gently, there's no issue except when standing at a light...my son has taking to throwing it in Park because it is so annoying.
I'm guessing that the engine is fairly worn and I'm getting some blowback but that won't cause this...I have a trans mount and can get a right motor mount...reading around about harmonic balancer issues, but it doesn't show up at speed. I've had U-joint issues with previous Mopars ('65 Fury/383, 83 Ram conversion van, 318, both 727s) and this does not feel like that did (which was more of a fine vibration when accelerating at speed).
Thanks