Lots of Heavy Vibration when Decelerating from HWY speeds

[4WD_Oregon]

I have an '83 4WD wagon w/165K which I just purchased. I am glad to have found this website.

If I am at highway speeds, 50 or more, and i let off the gas completely, the car shakes like crazy If I start to accelerate again, or ease the accelerator gradually, the shaking will almost completely go away, but if I don't decelerate gradually, i get lots of vibration.

At least one of the CV axles is new, brakes are new, struts seem fine. Have had all wheels balanced and rotated.

Vibration is also felt at 50 MPH during accel/decel or coasting, but lessens as you get above 53 or so.

NEW NOTE AT BOTTOM OF Webpage 2/13/2007


Any info will be appreciated and sorry if this is a repeated subject.

[takza]

Check the wheel lugs....and I'd guess the rear driveshaft...universals or center bearing?

[keith]

Critical question here, is the shaking mostly in the steering wheel or mostly in the body? If its in the front wheels, the steering wheel will shake the most, if its in the rear wheels or rear driveshaft, it will be felt mostly in the seat and floor, less in the steering wheel.

[shogun]

check your bushings, worn control arm bushings cause that, also check the steering rack, when it comes loose it shakes that way

[4WD_Oregon]

Vibration felt in steering wheel. Now suspecting right front side of having problems.

[Typrus]

It's possible that your tires have a road force problem. Does your tire shop just do a dynamic/static balance, or do they have a road-force roller? Vibrations at a certain speed can be caused by road force, which amounts essentially to inconsistencies in sidewall tension.
Unless you are in 4wd I'd pin it less on the rear drive assembly. If the rear driveshaft was powered at all times, I'd blame it.
Could be a CV. If one is new, it likely means the other went bad and they didn't replace its partner. This usually means the old one will die in short order.

Check your bushings. Sway bar to body, swaybar to control arm, control arm to body, upper strut mount bearing/bushing assembly. Also, check your tie rods for excessive play and your ball joint for excessive wear.

[4WD_Oregon]

I have my work cut out for me now and will follow all your great suggestions!

[Mattel]

I had this problem on an old Holden Kingswood.. fine with the power down but when coasting. Major bumpy feedback through the whole car.. ended up being the propellor shaft. Jack it up and feel for play in the shaft perhaps?

[/i]

[Chris]

My money would be on the rear drive shaft. To check it, unbolt it from the rear axle and strap it up out of the way. Then do a test drive.

[4WD_Oregon]

I have corrected information,

the vibration IS felt in the steering wheel. At the time it first happened, I was quite busy trying to get off I-5, so my first impression of the shaking problem was that it was the whole car shaking, rather than the steering wheel.

I am also sensing some problem in the front, passenger side wheel area. But, the car does steer fine, and corners very well. I do hear some ominous creaking sounds from the right front wheel area sometimes.

[ARCHINSTL]

I am also sensing some problem in the front, passenger side wheel area. But, the car does steer fine, and corners very well. I do hear some ominous creaking sounds from the right front wheel area sometimes.

4WD_Oregon -
CLICK THIS LINK AND READ THE THREAD !
Your noise may be similar to mine and could be a harbinger...
viewtopic.php?t=2195
Tom M.

[Typrus]

Just the wheel or everywhere is the next question.

Make sure everything is snugged up to spec. The downloadable FSM will have the torque specs.
Check your bushings while you are under there. Don't be afraid to grab something and give it a good tug and push (unless your jack-stands are precarious) to feel for excessive play.

Have you checked tranny lube level recently? I doubt its the issue, but it wouldn't hurt to look.

Hmmmm.... CV's are again a possibility. Wheel bearings are also. Does it get worse when you turn in one direction or the other?

[keith]

First, thanks for changing your avitar, it was very difficult to read your posts with all the flashing going on.

The best way I know to check a front end is to have someone rock the steering wheel back and forth while laying on the ground and looking at all the components. You will quickly see when one component is slipping against itself. You could also have too much toe out in your alignment.

[Typrus]

Smooth in, rough out, toe-out
Smooth out, rough in, toe-in.

What does that mean? Run your hands along the top of the tread of your front tires. If it feels notably smoother going one way or the other, and rougher the other way, you likely have a toe issue. Look up to see what they mean. If its rough going in, excessive toe-in is at fault. Rough out, excessive toe-out.

Dry-bump test. With engine off, but steering wheel unlocked, see how much the steering wheel turns before the wheels respond. You'll either need mirrors or a buddy for that part. If the s-wheel moves a lot before one or both of the wheels respond, then you'll want a buddy poking his head under the front end with a flash-light to see what is moving too much.

[lokahi]

had same problem . change your ball joints