Replaced Struts and Motor Mounts, New Noise and Vibration

[mikeDo]

I recently replaced the front strut assembly's and 3 out of 4 of the motor mounts aside from the rear (couldn't get the torx bolts out) due to a bad driver side strut and broken front mount. Thankfully the symptoms that prompted the repair went away.

Now, at low speeds (20-30ish mph) I have a vibration that I feel through the gas pedal and floor board mostly, then it goes away until around 70mph and I get the vibration again now through the wheel. This makes me think it a bad tire, but I dont understand why it just started the repair. I also noticed now when accelerating (3000ish rpm) the drivetrain doesn't sound as smooth as it was previously.

During the repair of the struts, when I was removing the lower bolts, the strut pivoted on on the knuckle outwards and seemed like it was able to pull the axle out of the inner housing. I dont know enough about the exact inner workings of the CV's to know if this was a problem or not.

I do know I need new front tires as the outsides of the tires are unevenly worn, so I will be getting new tires and an alignment soon.

 

[BossHog39]

CV axles over time wear a groove in the bearing slot in housing where the bearing's ride by default height of vehilce and when the axle slides out or in past the groove at the right points it cause the bearings to jump in and out of that groove on acceleration and cruizing (had on several vehicles both customers and my Lesabre) new struts more than likely changed ride height just enough to cause it to ride at the edge of that groove cause the vibration and strut replacement requires an alignment the caster has been changed. first step get alignment but more than likely will need new cv axles. and yes outside tire wear in tow in to far issue

 

[mikeDo]

That would make sense regarding the change in ride height, because the old strut on the driver side was around 4in longer than the passenger side unloaded off the vehicle.

 

[BuickGirlFromMars]

I recently replaced the front strut assembly's and 3 out of 4 of the motor mounts aside from the rear (couldn't get the torx bolts out) due to a bad driver side strut and broken front mount. Thankfully the symptoms that prompted the repair went away.

Now, at low speeds (20-30ish mph) I have a vibration that I feel through the gas pedal and floor board mostly, then it goes away until around 70mph and I get the vibration again now through the wheel. This makes me think it a bad tire, but I dont understand why it just started the repair. I also noticed now when accelerating (3000ish rpm) the drivetrain doesn't sound as smooth as it was previously.

During the repair of the struts, when I was removing the lower bolts, the strut pivoted on on the knuckle outwards and seemed like it was able to pull the axle out of the inner housing. I dont know enough about the exact inner workings of the CV's to know if this was a problem or not.

I do know I need new front tires as the outsides of the tires are unevenly worn, so I will be getting new tires and an alignment soon.

you also have to realize your smooth feeling was from worn out sloppy mounts
stiffer, newer are going to feel more harsh esp right away but should feel more responsive

 

[HotZ28]

Did you replace the motor/trans mounts with hydraulic, or solid mounts?

 

[mikeDo]

Did you replace the motor/trans mounts with hydraulic, or solid mounts?

The listing I bought them from on Ebay did not mention so I would imagine they are solid.

 

[JGBuick]

Engine mounts???

 

[HotZ28]

OEM mounts were hydraulic, which helped adsorb the engine & accessory vibrations from the cabin floor/steering wheel/accelerator/brake pedal.

 

[mikeDo]

CV axles over time wear a groove in the bearing slot in housing where the bearing's ride by default height of vehilce and when the axle slides out or in past the groove at the right points it cause the bearings to jump in and out of that groove on acceleration and cruizing (had on several vehicles both customers and my Lesabre) new struts more than likely changed ride height just enough to cause it to ride at the edge of that groove cause the vibration and strut replacement requires an alignment the caster has been changed. first step get alignment but more than likely will need new cv axles. and yes outside tire wear in tow in to far issueView attachment 45105View attachment 45106

So the culprit was in fact the CV Axle inner joint on the driver side. That was the side which had the strut assembly that was shot.

Thank you everyone for the help!

 

[Ultra Ego]

So the culprit was in fact the CV Axle inner joint on the driver side. That was the side which had the strut assembly that was shot.

Thank you everyone for the help!

Thank you for reporting back to help future members with the same problem.