Shake Rattle and Roll

[DeeVeeEight]

My 79 likes to shake and shudder at speeds above 70 mph. Most times the car is smooth and steady but sometimes I get this rythmic vibration that starts at the front and works it's way through the car to the rear then starts over again, sort of like waves of vibration that pass through the car.
I can feel it in the front of the car, then the steering column starts to shake, then the vibration goes to the rear, then it starts over again.... Lowering speed below 70 makes it all go away.
Your thoughts?

 

[Federal007]

My 79 likes to shake and shudder at speeds above 70 mph. Most times the car is smooth and steady but sometimes I get this rythmic vibration that starts at the front and works it's way through the car to the rear then starts over again, sort of like waves of vibration that pass through the car.
I can feel it in the front of the car, then the steering column starts to shake, then the vibration goes to the rear, then it starts over again.... Lowering speed below 70 makes it all go away.
Your thoughts?

I've got the same problem and would be real interested in responses to.

 

[Beagle 1]

Wheels out of balance, loose ball joints, tires, road surface,etc.

 

[agent20x]

unbalanced driveshafts, bad u joints, sloppy wheel bearings.

I had a similar issue, and it didnt go away until I did the rear end and had the drive shafts balanced. Also, one of my u joints was toast, so that certainly didnt help.

 

[sfallison]

I had the same problem - Bad U-Joint in the rear half shafts.

Have your wheel balance checked (easiest thing to do).

Replacing U-joints can't hurt - especially if they've never been changed!!

 

[Federal007]

I've checked all the U-joints, bearings etc just leaving the shafts. Was hoping not to go down that road but oh well.

 

[DARROW 74]

I've checked all the U-joints, bearings etc just leaving the shafts. Was hoping not to go down that road but oh well.

I had the same problem. It was the drive shaft, two hours labor and $65 to ballance solved the problem.....

 

[DeeVeeEight]

4 New Tires, wheels balanced, drive shaft shortened and balanced, 4 new Bilstein shocks, rear rebuilt..... I guess that means I need to check the half shafts.

 

[PowerRig]

Make sure adjustable strut rods are tight...........bushings not crumbling or missing

Both these items would cause vibrations......

Good Luck

 

[BBShark]

My 79 likes to shake and shudder at speeds above 70 mph. Most times the car is smooth and steady but sometimes I get this rythmic vibration that starts at the front and works it's way through the car to the rear then starts over again, sort of like waves of vibration that pass through the car.
I can feel it in the front of the car, then the steering column starts to shake, then the vibration goes to the rear, then it starts over again.... Lowering speed below 70 makes it all go away.
Your thoughts?

Is the rhythmic vibration you describe a low frequency? What happens at 80mph? Does it get proportionally faster?

 

[MYBAD79]

Check every bolt before you spend money on parts or labor.... these A-arm bushing bolts sometimes loosen (especially if they were installed without Locktite or even worse: with anti seize compound) they loosen and just fall off......

 

[DeeVeeEight]

I had the 'Vette out for a 3 hour tour yesterday (the weather started getting rough, the tiny ship was tossed)(JK) and I tried to figure out the vibration issues some more. It seems that the majority of my vibration is in the steering column. The column will shake from side to side in response to rough road surfaces. If I press upwards on the column/steering wheel when it vibrates I can just about eliminate the vibration. I figure that my tilt telescoping column, being extended so much to accommodate me being 6' 2", is amplifying the vibrations. Can the column be tightened up or firmed up in any way to help reduce column vibration?
I also ran the car at various speeds and the vibration frequency does not seem to change. The vibration is also NOT consistent at 72 mph, where it seems to occur most often.
So - is there any help for my steering column?

 

[PowerRig]

Shake Rattle & Roll

Had a similar problem a few years back, symptoms exactly as yours.

If the steering seems loose check IDLER ARM BUSHINGS as well as all linkage

bushings as these could be causing vibrations..........

By the way, how is your alignment and wheel balancing.....?

Are your wheels bent or damaged ?

I see your search has gone in a new direction.

Good Luck

 

[DeeVeeEight]

Update

I checked tire pressures yesterday before taking the car out for a long ride. I found one tire was over inflated? by about 8-10 lbs (to about 38 psi). I lowered all tire pressures to 28 psi and was very happy with the results, most of the heavy vibration is gone. I still have a little play in the steering column, hardly noticeable, but once that is tightened up I will reevaluate the vibration issue.
The vibration does not change with speed, however it does seem to be most noticeable on heavily traveled asphalt roads.

 

[TimAT]

Curious

You noted you had play in the column- does the wheel move up & down or just side to side? Up and down is a symptom of a loose tilt bowl and side motion could be a mast jacket bearing. I'm also 6'2" and I run the wheel all the way forward.

 

[DeeVeeEight]

You noted you had play in the column- does the wheel move up & down or just side to side? Up and down is a symptom of a loose tilt bowl and side motion could be a mast jacket bearing. I'm also 6'2" and I run the wheel all the way forward.

I have just the tiniest bit of movement up and down.

 

[boeing46]

Get the wheels re-balanced. Have a good front end man check all the bushing and connections on your frond end.
All ya have to do is hit a bump or a curb to mess things up.
Some Steel belted radials come apart inside. Put the front wheels on the back and see id there's a difference.
These are the easier and cheaper things to check first.