Dodge Dart 65mph Vibration?

Question

My '74 Dart has a vibration that starts in around 65mph. Its kinda like a pulsating vibration. I think its a U-joint but what does everyone else think it is?

Also when your driving and put it in neutral it doesn't vibrate just when your in D and driving normal at 65mph. I also pulled the drive-shaft and checked the U joints and they are clean and greased up. What do you think?

I have not had the wheels/tires balanced. How much would that cost? *wouldnt think its to much*

Answer 1

In addition to the other (excellent) answers, worn steering bushings can cause vibration.

Answer 2

I have had that problem on my Dart Swinger.
I have gone thru everything and not found it.
I have even reset the pinion angle of the drive shaft.
The last thing I need to do (and this makes total sence after being told about it from a Mopar engineer.)
is to change the tail shaft bushing in the rear of the transmission where the drive shaft slips in.
I am going to be doing it next month as soon as I get the car out of storage.
I bet thats it.
Have you had the wheels ballanced first?
Its easiest thing to do

Answer 3

Did you change the tire air over to winter air in the fall? The lower density of the molecules in the summer air can cause a vibration when driving in the 60-70 mph range. As this lower density closely emulates the expansion that is typical of summer high speed driving.
While you are under the hood you need to change your blinker fluid too, otherwise your flashers may flash out of sequence, which is a moving violation in NJ.

Answer 4

Isolate the problem(s)-
1.Raise your car on all four wheels and while someone holds the front right tire shake your front left tire and see if it is loose. Shake up and down and side to side. Excessive play followed by clunking sounds indicate worn suspension parts.
Check the rear wheels for loose components,with the car in neutral, turn one rear wheel and hold the other to check the differential to hear any noises. Turn the driveshaft manually to turn both wheels and listen for noises, loose transmission mount, etc.
2. Balance your tires, check for bent rims. Break the beads on the tires and see if any of the four tires has water,mud and/or fix-a-flat on them.

3. Get a four-wheel alignment specialist to check your rear wheels in reference to your front wheels. I believe it is called thrust angle alignment. Your front wheels are aligned in relation to the angle of your rear axle's alignment.
4.Remove the driveshaft, have it checked at a driveline shop.
Prop the car's front wheels on a tow dolly and tow it to 65mph. If the rear end suspension/diff. is at fault and not your driveshaft it will vibrate minus the driveshaft.(plug your transmission rear tailhousing). You might have a rear bearing failure, rear bearing retainer loose.


5.Check the rear suspension at a dynamometer. You can accelerate your car at 65mph and visually check for leaf spring wobble, your springs are worn, replace the bushings and shackles.

Answer 5

Definitely the U-Joints.

Answer 6

my dad had an old truck that did the same thing, ended up being a bent drive shaft. not sure how that would happen on a car but its worth a check.

Answer 7

it sound like a u-joint. to test, park on level groung, apply parking brake, crawl under ,grab driveshaft and twist. If you hear or feel a clunk, then it's the u-joint.

Answer 8

Sounds like your tires need to be re balanced

Answer 9

u-joints,wheel bearings ,bent rims ,tire out of balance or out of round

Answer 10

Front end alignment ,warn tires,wheel bearings, any or all of the above.