Vibration When I Let Off The Gas

[Red91hatch]

I have a vibration when I am going around 60-70 mph, when I let off the gas. When I am accelerating it is non existant. 1991 5.0 hatch, 5spd. Basically stock with cat back exhaust. I know I do need new front tires, but this vibration feels like its in the driveline. Any help would be appreciated.

 

[86bluecobra]

So you feel it in the steering wheel or do you feel it in your seat?

 

[Red91hatch]

In the seat. Almost feels like unbalanced tires, but it is only when I let off the accelerator. When I hit the gas, even slightly, it goes away.

 

[Onefine88]

Could be the u joints on the drive shaft. Check to make sure the bolts on your u joints are tite. Or it could be time for new u joints.

Good luck

 

[Red91hatch]

Was thinking so, I will check them. Thanks again.

 

[86bluecobra]

Could be the u joints on the drive shaft. Check to make sure the bolts on your u joints are tite. Or it could be time for new u joints.

Good luck

I had a vibration in my drivetrain and it turned out to be that somehow the 4 bolts holding my driveshaft to the rear end had loosened off. Went away after they were tightened up.

 

[Gearbanger 101]

Look for bad U-joint....and believe it or not, loose wheel nuts. Brought my old Ford Ranger into my High-school shop class as a teen. Checked all the brakes and I must have forgotten to tighten the lug nuts on one wheel when putting it back together. Made a hell of a vibration everytime I let off the gas. Checked it out when I got home and sure enough....5-loose lug nuts.

 

[kenneth seymour]

hey brother...you need to change your harmonic balancer like yesterday...if that gives up, the motor is toast! good luck and hope it is just the u-joints

 

[Gearbanger 101]

hey brother...you need to change your harmonic balancer like yesterday...if that gives up, the motor is toast! good luck and hope it is just the u-joints

The harmonic balancer should vibrate at all RPM, whether he's in gear, or not under engine load. The fact that he's getting it just under decceleration, tells me that his balancer likely isn’t the problem.