Engine shakes under acceleration

[standup303]

Put a timing light on it. You'll spot it real quick if you cannot see the timing mark on the balances, or if the mark is WAY off the pointer.

Awesome thanks I’ll try this weekend.

 

[standup303]

Mr dramatic, not really. Was expecting another post and run, others were thinking the same after a week...it only takes a couple of seconds to say "Thanks, I'll get back to you guys". *sigh* Anyways, good luck.

I should have. My bad on the mr dramatic comment. Appreciate the feedback. I’ll keep hunting for the issue this weekend.

 

[Dave999]

has the rear trans mount turned to cheese, when they go soft the trans movs left or right under load. the diff doesn't. and you get vibration much like you would with an pinion angle issue.

the 4 pin joints when angled speed up and slow down. same angle at each end the speed up and slow down matches. and all is good. different angle at each end, makes the shaft vibrate as each joint PINGs through the tight bit.

Dave

 

[gesklund]

Had a friend have a similar issue with a 360. They were using the wrong flywheel. The shaking was there the first time they fired up the engine after installation. It became noticeable after about 2500 RPMs. Is the engine newly installed or has this been working without issue until now? The issue is, he was using a 318 flywheel. A 318 is internally balanced. A 360 needs and offset balanced flywheel

 

[standup303]

Hey guys, so now the car has the vibration even at idle, all the way through the RPM range. I ended up taking it in for an alignment and had them take a look. They recommended replacing the balancer first then if that doesn’t do it drop the trans and look at the converter and flex plate. Attached are some pics and a video of the balancer. I don’t see any vibration that’s concerning. I don’t have a timing light to set up either. Do you guys see anything off?

However, I can now feel the vibration a lot more in the cab and almost feel like it’s closer to the trans tunnel….

Thanks in advance.

 

[standup303]

 

[moparlvr166]

Do you have anybody that can help you? If so, get it up safely on jack stands, get under the car and use a rag so you can touch items to feel the vibration from front of engine to back of trans while someone controls the throttle to get the most vibration. try in drive or rev and see if it changes and let us know what you find.

 

[RustyRatRod]

You need to identify the crankshaft. Period. Until you do that, you're just playing around.

 

[Phreakish]

As others have said, it sounds like typical imbalance.
There are different externally weighted dampers, flywheels or converters for 318/340,360,and Magnum engines.
If either the damper or converter has been changed, they're suspects.
Mounts, bad plug wires or plug, or a cam going away could all also have a bit of a shake which worsens.
All of these can be checked or ruled out without the engine running. If something is wearing, running it is just risking catastrophic failure.
Inspect the mounts, pull the valve covers, check for loose pushrods at TDC of each cylinder, inspect plug wires and plugs (or replace if they're very old or show wear).
Pull the belts and look for loose bolts on any pullies or brackets then pull the damper and look for damage and to confirm whether it's the right configuration for your engine.
Next, try to get into the bellhousing area and see if there's a weight welded to the converter. If you search for images of stick converters, you'll see what it usually looks like.
Sharing pictures of all these things can also help plenty of the members here advise you.

 

[standup303]

Thanks everyone. I’ll go on the hunt some more this weekend and post up what I find.

 

[oldkimmer]

I would say the damper slipped. Have a good look at your first pic. Plus u have serpentine set up which will magnify the vibration. Kim