[Vista Cruiser]

Has anyone ever had a harmonic balancer fail, and it caused the car to vibrate? A harmonic type vibration?

I have a 400 sbc with a StreetDampr (Fluidampr's little brother) on it. While I was messing with the transmission governor weights to change WOT shift points, I over revved the engine once or twice. Its gotta shift some time, right?

Well, since then I've been chasing a vibration around that I can't seem to find and I have rebuild, balanced or replaced about every rotating part at the front and back of the car. I have not replaced anything in the engine or tranny yet.

Can a vibration in the engine cause the whole car to shake?

It doesn't seem to vibrate in neutral revving up.

I guess my question is has anyone one had a dampener fail that they could feel while driving?

Thanks

JImR

 

[Siggy_Freud]

They can become old and begin to become out of balance yes. However the balancer is spinning just as much and just as fast in neutral.

If your vibration goes away in neutral your looking at more of a driveline problem (tailshaft, driveshaft, etc.) than an engine problem I'd think.

 

[johnsongrass1]

Are you sure it's not a bent pushrod or valvetrian causing a miss?

If the miss is slight you may not feel with no load.

 

[k-star]

ENGINE

Over reved engine,,, and a vibration under load and not at idle.... Sounds like a busted valve spring to me...

do a quick compression test and it will show up if that the problem

keith

 

[milehifordfreak]

sounds like a bent push rod to me

 

[Vista Cruiser]

I'll check it out over this long weekend coming up.

Thanks

 

[docvette]

Dampner

Doc here:

HAPPY THANKSGIVING!

Are you Sure you didn't knock the Vacuum line to the modulator valve off while working on the tranny? On either end?

While your checking things DO check the dampener...anyway, even if it isn't the problem..If it comes apart at highway speeds it can be deadly...

But as all have said sounds like a valve train / vacuum problem.

Doc imp:

 

[Vista Cruiser]

Sorry, no vacuum lines on this tranny, 700R4, but I did check the other vacuuum lines last night and they all looked connected. There is only two other not counting the brake booster, which is new, and the PCV line.

I can't feel a miss but I'm willing to look at the valvetrain.

Thanks again for the advice. I'll be back with the results.

 

[milehifordfreak]

vista,

you can also do a cylinder balance test and see if there is one cylinder that is not hitting (rpm drop) as good as the others.

 

[Vista Cruiser]

Are you talking about pulling one plug wire at a time?

I usually get bit whenever I do that...

 

[milehifordfreak]

you can do it that way, or if you have acess to a scope that can do that, that is the easiest way, without messing up your hair.