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Crank Walk? Balancer Failure?

Zeppelin264

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So back in August I installed the Borgeson steering conversion box. Got all done after 2 days and took the car around the block to make sure everything is good to go. I get back to my buddies place and pop the hood and as I'm listening to the valve train click away I rev the engine up just a little and the balancer moves in and out with the rev of the engine. I confirmed this a few times, drove the car home, parked it and put it on the back burner.

Fast forward to today, I decide to fire the car up (first time since August) and sure enough, at a cold idle the balancer isn't moving at all! That day in August was very hot out, and under hood temps were even hotter.

So I'm wondering if either A: the oil thins out, metal warms up and the crank starts to move, or B: when the temp outside is hot the rubber begins to get squishy on the balancer causing it to move in and out?

Has anyone ever had a "crank walk" that only happened at a hot idle?
 
Put a dial indicator on your front pulley or balancer bolt, and see how much movement fore and aft it has. Should be no more than .017"
 
If you started the car and the crank pulley was not moving,it's junk and you need a new one.Get one for the level of performance you plan on getting to:thumbsup:
 
Doesn’t that mean the key is gone or sheared? How can the pulley not turn? Isn’t it all metal from the crank to where the pulley bolts to?

That’s gotta be crazy, engine running but no crank or any accessories running.
 
So if its solid(running true) when cold and moving in and out while hot you think its the balancer?
 
Is it moving in and out or is it not spinning/turning with the engine? I’m not following.
 
Engine runs, pulley is driving all accessories. When cold, pulley runs true and straight. When engine is hot, if you rev the engine up a little you can watch the pulley move away from the block and suck back in when it returns to idle. Movement is probably about 1/8" - 3/16" inch. I figure that is too much for thrust bearings.... I hope.
 
That should not be happening. Make sure you investigate and remedy the problem before you have a major failure.
The crankshaft should only have about 6 or 7 thousands end thrust which you would not be able to see.
However I have heard of harmonic dampers coming lose or falling apart many times.
 
That seems like your thrust bearings are damaged.
 
Remove the bottom pulley and balancer
20190103_101843.jpg
bolt. Use a puller and remove the balancer and inspect it closely. Check in/out movement of crank with balancer off, but don't start it. By this time you will know the problem. I can't see that the thrust bearing could get 1/8" pf play. It would be hitting the block by then. Here's a close up of a good 400 thrust bearing upper half. You working on a 440? I guess the thrust bearing could be worn 1/8", but very unlikely. It gets oil full time.
 
So back in August I installed the Borgeson steering conversion box. Got all done after 2 days and took the car around the block to make sure everything is good to go. I get back to my buddies place and pop the hood and as I'm listening to the valve train click away I rev the engine up just a little and the balancer moves in and out with the rev of the engine. I confirmed this a few times, drove the car home, parked it and put it on the back burner.

Fast forward to today, I decide to fire the car up (first time since August) and sure enough, at a cold idle the balancer isn't moving at all! That day in August was very hot out, and under hood temps were even hotter.

So I'm wondering if either A: the oil thins out, metal warms up and the crank starts to move, or B: when the temp outside is hot the rubber begins to get squishy on the balancer causing it to move in and out?

Has anyone ever had a "crank walk" that only happened at a hot idle?

I think your putting too much emphasis on the temperature out side.

If the crank is moving enough that you can see it, you have a thrust bearing issue. The next question is why did the motor loose the thrust bearing. Usually it's a torque converter issue or a manual transmission car.

Certainly check you damper, but I'm not real optimistic.
 
My 2-cents.... It is either your thrust bearing (middle main bearing) or the balancer itself. Maybe you should just loosen the belts & see if you can move the balancer in/out by hand and look? I have had a balancer go bad myself and it is A LOT easier to change than a main bearing.

As I see it, your only possibilities are:
a. main pulley bolts coming loose
b. balancer going bad (rubber inside)
c. thrust bearing in engine bad...really bad.
 
Pry the crank back and forth and watch the converter. Does it move excessively.? That'll point you in the right direction.
Doug
 
I'm thinking thrust bearing. I can't imagine the balancer not squealing if it's slipping. You can mark the inner ring to the outer on the balancer, reproduce the motion, and recheck the marks on the balancer.

Here's a '68 440 steel crank with the rear thrust bearing land worn out of it.....
WastedThrustA.jpg
 
Since the pulley is attached to the solid part of the balancer, and the solid part of the balancer is press fit onto the crank shaft and bolted, I would say the crank bearing thrust is loose and whole crank is walking, or the balancer is slipping on the crank shaft,( would have to be really loose and the bolt is backed off, I would think its unlikely, because the key way keeps it from spinning at least), or the bolts holding the pulley on the balancer are loose.
Pull the belts tension off the pulley and see, start there. The outer part of the balancer could be messed up too, but that would be a separate issue.

I would guess your pulley is not bolted tight on your ballancer, perhaps when the belts heat up they loosen up just enough to let the pulley slide out a bit on the bolts? It could be dangerous as is, if something let's go.
 
By the description given, the only way I see this has any possibility of not being a thrust bearing issue is if the damper bolt doesn’t have the damper help tight against the crank gear, the damper fit on the crank is on the loose side, and the damper is walking in and out on the crank.

Yeh...... that’s really a loooong shot.
 
Engine runs, pulley is driving all accessories. When cold, pulley runs true and straight. When engine is hot, if you rev the engine up a little you can watch the pulley move away from the block and suck back in when it returns to idle. Movement is probably about 1/8" - 3/16" inch. I figure that is too much for thrust bearings.... I hope.

So is it the just the pulley moving, or the dampner too? Does the pulley move together with the dampner?
 
Furry & PRHeads make a good point..... it "could" be that the balancer bolt is loose (unlikely, but possible).

FYI- I had a balancer go bad on a *cough* Ford & it didn't squeal. Looking back, it did chirp once or twice, but I didn't realize what it was. Me, one standard shop & a Ford dealership couldn't figure it out....2nd dealership caught it by marking the balancer with a line from the center bolt to the outside, ran the engine & then the mark didn't line up anymore. I had a poor charging situation since the balancer/pulley was only spinning maybe half speed.
 
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