440 harmonic balancer looooose!

[Shallenger]

I recently picked up a 1975 440 w/trans that the owner claimed low miles that was out of a motorhome winnebago. Checked it all out and disassembled it to make sure it was legit. Did notice heat tabs on the freeze plugs. Engine was clean inside and was rebuild at one time, .030 pistons. Cylinders has no ridges but when I was about to take off the harmonic balancer by installing the removal tool the balancer slid right off which was I was like “oh dam” and I’ve build plenty of small block engines before haven’t done a 440 yet just never ran into a problem like this and I’m wondering if 440s are like this which I highly doubt or is it just a bad harmonic balancer?

 

[Challenger RTA]

Is it loose because balancer is bad? Or is it moving because the thrust bearings are bad?

 

[Shallenger]

I think the balancer is bad because they are usually a press fit and no the thrust is good

 

[Challenger RTA]

The material there made of deteriorate. I do think someone rebuilds them.

 

[Shallenger]

The rubber is still intact but the center hole is the problem unless the crank is the problem.

 

[Challenger RTA]

You can see the wear on the crank? I think the crank metal is harder than the balancer. Clean and buff the crank with 120 grit. Then check. What's the keyway look like? I don't know the specs.

 

[Shallenger]

Might be wear and I wiped it down and it measures 1.528 on the crank area where the balancer presses on. The key way on the balancer looks good. I don’t have a snap gauge to read the inner diameter of the balancer tho.

 

[Chryco Psycho]

You need to measure the crank & see if it is in spec , the damper is done , it is in very bad shape .
It would depend what your plan is for the engine , you could do a 512 stroker kit with a new steel crank , rods & pistons this would allow you to use a internal balance damper instead

 

[Challenger RTA]

To me it looks ok. There are some very good engine builders and machinist here. As I said need to know the spec for the cast crank and year. I have done some. I can feel 2-3 thousands wear on a 350 Cummins valve and others. I put them aside then mic them.

I had a similar experience. On one of my backup cars I changed the timing belts. I knew I need to finish checking it. One day my son came and got it. He was working 7-12 for months at a power plant. I told him it needs checked out. I knew I need to finish something. Because I had to drop working on it. Probably had to go to work! One morning he calls me as he's coming from the power plant night shift. He said it's cutting out and has no power. I ask him what the gauges are showing. He said the alt light was on. I told him turn just the headlights off. He said it got better. He made it 5 miles to an other house we have. I went and looked at it. As I told him. It need check! Well the crank shaft bolt need torqued. It went for about a month before it worked loose. It tore up the pulley and the key. Replaced both. He still drives it. No matter how good you are. Or you think you are! When you do a lot. Something will eventually go wrong.

That's why I think the crank is ok. But check it. I know there are repair sleaves for cams. Not sure about a crank.