Engine (?) Vibration

[dgs]

I'm not sure 'vibration' is the right word. Let me describe what's happening.

My 352 Cruise-o-matic 'Bird feels like the engine is off balance under load. Rev'ing the engine in Park or Neural it's not real noticeable, but under load when accelerating the whole car shakes like someone clamped a weight on the side of the drive shaft. Disconcerting to say the least. No shake in the wheel, it goes away at cruise speed or while coasting.

Up until now, I've had no problems with the drive train to speak of and I've done nothing to it since I got it 4 years ago. The odo shows 51K, but I'm pretty certain it's 151K. The only things I've done to the engine since I got it is change the plugs & wires, install Petronix & a Petronix coil, change the radiator and heater hoses, change the radiator cap and thermostat and replace the leaky fuel pump this spring.

I haven't touched the tranny at all and it shift good and hard, even would chirp the tires into second gear with the old skinny black walls that were on it.

I haven't looked into it yet, I'm not sure what to check. Universal joints? Engine miss? What else??

[Alexander]

RE: Engine (?) Vibration

I have had this happen to me. Change the u-joints.

Does the car "clunk" when you go from drive into reverse? this a sure sign of a worn u-joint.

Alexander
1959 Hardtop
1960 Golde Top

[byersmtrco]

RE: Engine (?) Vibration

Check the trans mount & mtr mounts too.

[JohnG]

RE: Engine (?) Vibration

Under the heading of less likely causes should the U joints not turn out to be the culprit, check the balance of your rear tires and
at the same time the balance of the brake drums. Never heard of that? Me either, but there is an article in the current Auto Restorer about the vibrations you can get from out-of-balance rear drums. Easy to check and fix.

In a totally different area, an engine which is running too rich will sometimes shudder while being leaned on to accelarate. If this is the case then backing off a bit with your foot will cause the vibration to cease.

An area I know little about but which others do would be the harmonic balancer. Do these deteriorate with age? Since rebuilt ones are available, their exisitence would seem to indicate that they do. But I don't have any experience with the symptoms of one that needs replacing.

John
58 Hardtop

[dgs]

RE: Engine (?) Vibration

Thanks for all your help.

It does 'clunk' when going into gear, has since I got it. Sounds like new U-joints are likely in my future.

At this point, it'll have to wait until next spring to check. Boy, the projects are adding up faster than I can get 'em done. Top to go on, deck lid cylinder hose to change, rear interior panels to paint, rear seat cover to change, front end kit & shocks to install, power windows to fix. Yikes.

[tarps3]

RE: Engine (?) Vibration

welcome to squarebirds!
the list never gets any shorter - the items just change names.

good luck!
Casey
60 hardtop

[byersmtrco]

RE: Engine (?) Vibration

Yup, sounds like another 60 Conv I know of.
They're never done. Lotta fun though. Can't wait to get mine back and put the top down. Rotate your tires AND your drums. See if the vibration changes. UJoints are cheap and easy fix. Do those things and see what happens. Sounds like you have something simple wrong.

John