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Harmonic Balancer Recommendation

money pit

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Can anyone recommend a harmonic balancer for a 1978 360 engine. I have a vibration in park and neutral, and at at about 3000 rpm. The motor and trans mounts have just been replaced (quality parts) The torque converter weights are in place. The engine was rebuilt about 3 yrs ago and the crank was balanced. I checked the harmonic balancer to see if it shifted. I checked TDC with a TDC tool (in the spark plug hole). TDC matches turning the engine both ways. I don't think the balancer was replaced when it was rebuild. I was going to start with the balancer before going deeper. There are so many balancers on the market, I don't know what to buy. Thanks
 

pschlosser

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If you really have an internal engine imbalance, that would be corrected by the harmonic balancer, the engine may need to come out, engine torn down, and everything balanced proper at the component level.

that said, are you sure your vibration is from an internal imbalance? If so, you should have seen this issue from day one after rebuild.

Has anything changed on the engine since before and after you noticed the imbalance? Could it be there is something else causing the vibration you feel... where, at the steering wheel?

The balancer is held in place on the crankshaft with a woodruff? key. If that is missing, it seems possible the balancer rotated some on the crankshaft, perhaps causing your vibration.

Buying somewhat random balancers and hoping for a balance just by bolting on the "right" harmonic balancer seems like such a random long shot. I hope I'm wrong.
 

money pit

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If you really have an internal engine imbalance, that would be corrected by the harmonic balancer, the engine may need to come out, engine torn down, and everything balanced proper at the component level.

that said, are you sure your vibration is from an internal imbalance? If so, you should have seen this issue from day one after rebuild.

Has anything changed on the engine since before and after you noticed the imbalance? Could it be there is something else causing the vibration you feel... where, at the steering wheel?

The balancer is held in place on the crankshaft with a woodruff? key. If that is missing, it seems possible the balancer rotated some on the crankshaft, perhaps causing your vibration.

Buying somewhat random balancers and hoping for a balance just by bolting on the "right" harmonic balancer seems like such a random long shot. I hope I'm wrong.
I don't drive the car much and when I do, I rarely drive over 55 mph. I noticed the vibration at 60 mph +. I adjusted the exhaust because the pipes were hitting the floor, replaced the trans mount first (it was broken), then the motor mounts. The things that I replaced within the last year, were the rear end, the drive shaft (had to have it shortened), and the leaf springs. The posi has developed a clicking sound, which I'm going to have it looked at next week. The engine vibration I feel more in the seat rather than the steering wheel. Worse comes to worse, I'll pull the engine have it looked at. The rebuilder is reputable and well known. Thanks
 

Steve340

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I would contact the rebuilder and first confirm - is the engine internally balance or external balance.

If he has converted it to internal balance it will not need any counterweights.
 

money pit

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I would contact the rebuilder and first confirm - is the engine internally balance or external balance.

If he has converted it to internal balance it will not need any counterweights.
I had talked to the builder while it was being built. He told me that he had forgotten that the 360 was externally balanced until one of his guys reminded him.
 

Steve340

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So by the sounds of it it will still be externally balanced. That can make it tricky. It is hard to balls up an internal balance, but due to the counterweights being so far off centre with external balance a little too much or not enough can cause a problem.
 
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