67 BB driveline vibration.

[Richard S.]

On the off chance someone may recognize my problem from this symptom, I'll describe something which seems strange to me. The car is a 67 427/435 coupe with 411 rear and very few miles since a complete body off restoration. With the gas tank almost empty and cruising the car/shifter vibrates considerably. BUT, with the gas tank filled to the top, it vibrates much less. Any clues here? Wheels are balanced and no vibration from engine.(As far as I can tell.)
What can I check/look for?
Thanks.

[John H.]

Re: 67 BB driveline vibration.

Rick -

Logically, the only dynamic change from the added weight of a full fuel tank would be the operating angle of the half-shaft U-joints; were they replaced?

[John H.]

Re: 67 BB driveline vibration.

Rick -

Logically, the only dynamic change from the added weight of a full fuel tank would be the operating angle of the half-shaft U-joints; were they replaced?

[Wayne W.]

Re: 67 BB driveline vibration.

If the car is sitting either too high or too low, or the alignment is off. This symptom could be the result. U-joint angles.

[Wayne W.]

Re: 67 BB driveline vibration.

If the car is sitting either too high or too low, or the alignment is off. This symptom could be the result. U-joint angles.

[Brandon K.]

Did you replace the rear spring

or re-arch it? Sometimes you need to put a little mileage on the car to break the spring in until it settles down to correct ride height.

[Brandon K.]

Did you replace the rear spring

or re-arch it? Sometimes you need to put a little mileage on the car to break the spring in until it settles down to correct ride height.