440 vibration in neutral
 

About 30 years ago Pa had to replace a 440 magnum. He ordered what was called a short block. The car has vibrated in neutral ever since. Several years ago I replaced the harmonic balancer because the timing marks didn't line up. The car still vibated. Last winter I ordered a heavier weighted torque converter from year one. The heavier weights made the vibration worse. I've heard a lot of ideas about why this is. Some people tell me the flexplate could be the reason. The car is a 1970 charger r/t. The engine is a mid_70s 40 std (5t440). Block was cast in nov 74. My latest idea is to pull the engine and examine the crank. The engine needs freeze plugs now and the valve covers started leaking. My cousin has never seen a 440 with balance weights. How can this be fixed?

440 vibration in neutral
 

The first balancer which I still have weighs 7.75l bs. The one I ordered weighed 13.25 lbs. It has 440 cast stamped on it and the timing marks line up. Didn't quite solve the problem though. The heavier weights on the torque were definitely a mistake. Is it safe to chisel the weights off torque converters? My cousin won't touch the car without knowing the problem.

Your problem has to do with how the engine is balanced. If you have a steel crank the engine is internally balanced and requires no weights on the dampener or torque converter.

If you have a cast crank the engine is externally balanced and requires weights on the converter and dampener.

It sounds like you have an internally balanced engine with external weights. If you get a neutral balancer converter, and the right dampener you should be fine.

I've seen and heard of even more reman long and short blocks not being rebuilt right. I'd try what Commando said. If it still happens then you may have to tear down the motor and have the rotating assembaly balanced properly.

I was just relying on the fact that it was done properly, I hope its as easy as I said. Good Luck!

440 vibration in neutral
 

I've been researching harmonic balancers. I though I had the right one when the timing marks matched. It would seem like the thickness of the balancer would affect belt alignment. I'm not completely positive the engine has a steel crank. What exactly is the difference between a short block and long block? I may have pulled the correct balancer. Several possibilities here

440 vibration in neutral
 

The fact that the timing marks didn't line up on the first balancer suggested that the engine needed a new balancer. It apparently only went on one way. I still haven't figured out what the woodruff key is for. The first balancer is rusty now but the rubber ring look intact. Also the pulley bolts appear to be offset. I'm not sure if this came with the short block. The old man that swapped the motors years ago may still be living. He probably wouldn't remember much.

440 vibration in neutral
 

The car was driven three miles with a busted radiator hose. They said the pistons melted to the block. The new engine has about 2000 road miles on it. I used to start it up once a week. I'd like to get the shake out of it before driving it much. The torque converter we pulled out had looser guts than the new one. My cuz has his reservations about knocking the weights off a torque converter. I also thought about looking for a cast crank.

a short block is a rebuilt engine that was orderd with no heads, a long block comes with heads and intake. if you pull the oil pan the counter weights would be sharp on a cast crank. and forged has more of a radius on the counter weights if you still are not sure. cast cranks 8698 461, or 4027 175, or 3751 888 have these numbers on the big counter weights forged cranks have 2206 160, or 2206 158 on the big counter weights. if it has a forged crank you will be safe with knocking the counter weight off of the converter. grind the welds down flush, gl

Where are you located at, I have a cast crank lying around if that is the route you choose. Not near by it, but I could get you the part numbers in about two weeks.

440 vibration in neutral
 

Thanks for the info. They used what they could off the old motor. Not sure if the original heads cracked or not. I don't know if the balancer I pulled was on the original 440 mag. The torque converter we pulled had two weights and orange paint like the valve covers. I read that the 1970 440 mags had a special cam. I wish I had time to work on it.