1977 Trans Am Pontiac 400 Vibration 1700-2000 RPM?

[bmmaroh]

I started noticing a vibration between 1700-2000 rpm.

This happens while in neutral if I rev the engine to that range or while I am motoring down the highway at that rpm range.

It's not a shake your teeth loose vibration, but you notice it.

This is a 400 with the original 4-speed.

Could this be a clutch or a flywheel?

Any ideas are much appreciated.

 

[Knightrider189]

Could be that.

Have you checked the harmonic balancer?

I don’t know if that could be your issue, but it's worth looking at.

The driveshaft could also be out of balance.

It could be any number of things.

Please let us know what you find.


1989 Pontiac Formula Firebird, 5.7, all OEM

 

[bmmaroh]

Because I can cause the vibration while the car is not moving, I feel like it is coming from the engine and anything connected to the engine.

I will take a look at the harmonic balancer.

Not sure how to determine if it is the flywheel.

 

[Elwood]

Check the bolts from the drive shaft to the rear end and make sure they are tight.

What kind of condition are your universal joints in, and how old are they?

I would also check the drive shaft to ensure it is not slightly out of balance.

In the last car, I had a problem with the vibration; I told the guy the universal joints were Gng bad.

He didn’t fix it, but they finally came apart, and the drive shaft came out while his wife was driving down the highway.

It was raining, and she had to walk up an embankment to a gas station, ruining her shoes and dress and falling in the mud.

She wanted to kill him, lol.