New Suspension - Now Car Vibrates

[gallydif]

Hello my fellow forum members. Today, I had new shock absorbers installed by my mechanic (sorry for letting my fellow DIY'ers down). All 4 are Monroe- 5801 and 5955. That is it. No new tires, ball joints, etc. Just shock absorbers. The shock absorbers are the correct fit for the model vehicle- '96 Roadmaster.

On the way home there was this terrible vibration and the faster I went, the worse it became. It didn't allow me to go over 55mph as the vibration got so bad. The whole car vibrates including the steering wheel. Even coming off the line from a red light at a slow speed, every time the tire made a full rotation I could feel it. It felt uneven. *This is something new and didn't happen prior to the installation*

Is this normal and means I need an alignment now? Or did new problems besides that surface with this new installation. I've read online it can be alignment, balancing, tire bulge/damage, bad suspension, and motor mounts. Well by doing process of elimination the tires are fine (no bulge/damage) and I don't think it needs balancing as these are the same tires as before.

Please help! Thanks

 

[Nick1994]

You don't need an alignment after replacing shocks, only with struts with new springs (which your car doesn't use)

Rotate the tires and see if the vibration changes.

Otherwise it's probably a bad U-joint or a bad wheel bearing.

 

[KingCake]

New shocks could change ride height which does affect alignment. OR the mechanic loosened some cam bolts somewhere to get the shocks in and out for clearance reasons.

 

[03cvpi]

I would suspect the mechanic left some lug nuts loose, or a disc rotor is not correctly seated. Unless they are air shocks, there should be no change in suspension geometry. The shocks just dampen spring movement, they do not hold the car up. Some high performance gas charged shocks can change the ride height very slightly. But I have never seen them change the height enough to affect the geometry.

 

[Brybo86]

I would take it right back and have him check his work.

 

[Nick1994]

Originally Posted By: KingCake
New shocks could change ride height which does affect alignment
Uh...
What?

 

[KingCake]

Originally Posted By: 03cvpi
I would suspect the mechanic left some lug nuts loose, or a disc rotor is not correctly seated. Unless they are air shocks, there should be no change in suspension geometry. The shocks just dampen spring movement, they do not hold the car up. Some high performance gas charged shocks can change the ride height very slightly. But I have never seen them change the height enough to affect the geometry.


almost all modern shocks are gas charged

 

[KingCake]

Originally Posted By: Nick1994
Originally Posted By: KingCake
New shocks could change ride height which does affect alignment
Uh...
What?

If the the old shocks lost their gas charge and got aligned at a lower height it will affect the alignment. Just like if the driver is a huger 300+ lb person you have to put ballast weight in the driver seat to properly set alignment.

 

[KingCake]

0.5" difference in ride height will throw toe angle out of spec in most cars.

 

[Andy636]

Start simple...make sure they tighten the lugnuts.

 

[Nick1994]

Originally Posted By: KingCake
Originally Posted By: Nick1994
Originally Posted By: KingCake
New shocks could change ride height which does affect alignment
Uh...
What?

If the the old shocks lost their gas charge and got aligned at a lower height it will affect the alignment. Just like if the driver is a huger 300+ lb person you have to put ballast weight in the driver seat to properly set alignment.
We're talking about shocks here, not struts.

 

[Yup]

Originally Posted By: Andy636
Start simple...make sure they tighten the lugnuts.


+1 this. Had work done years ago before a long trip. Horrible vibration on the way home. Turned off to check things over...one wheel sheared off lug nuts and all other wheels had finger tight lug nuts. Oops, someone forgot to tighten! They did, however, "make it right".

 

[gallydif]

yes, it changed the ride height slightly as the previous absorbers were really old.The back driver side wheel wasn't completely snug so I tightened the lug nuts hoping it would be that. Did the test drive. Still vibrating unfortunately so it wasn't that. Could it be a screw for the shock absorber wasn't completely tightened?

The wierd thing is the first 2 miles I drove was fine and then it went down hill from there. Became worse. Like if something loosened up.

 

[03cvpi]

I had to replace some OEM front shocks in an 05 crown victoria, the left front shock was completely dead (no gas or oil) and the other still fine. We replaced them with Bilstien HD Performance shocks. Before the shocks were replaced the left side was low by 1/16 of an inch or 0.0625, after replacement the car was almost level. Within 1/32 of an inch. The left side was the low side after shock replacement, probably due to loss of spring tension by driving on a dead shock absorber for a few thousand miles. The work order was for an alignment, but the dead shock caused the vehicle to feel like it was out of alignment, we replaced the shocks, checked the alignment and sent the car on it's way. I've personally never had to re-align a vehicle after shock replacement, but I suppose it could happen.

 

[Tosh]

Originally Posted By: gallydif
yes, it changed the ride height slightly as the previous absorbers were really old.The back driver side wheel wasn't completely snug so I tightened the lug nuts hoping it would be that. Did the test drive. Still vibrating unfortunately so it wasn't that. Could it be a screw for the shock absorber wasn't completely tightened?

The wierd thing is the first 2 miles I drove was fine and then it went down hill from there. Became worse. Like if something loosened up.

It could still be that the nuts are unevenly tightened, causing a wheel or rotor warp. Refit all the wheels.

 

[MaximaGuy]

A alignment should be done everytime you change a suspension. Firestone has some deal for lifetime alignment for $150 or something, a great deal, someone told me about it. I couldn't believe what I was hearing!!! Check it out.

 

[KingCake]

Originally Posted By: Nick1994
Originally Posted By: KingCake
Originally Posted By: Nick1994
Originally Posted By: KingCake
New shocks could change ride height which does affect alignment
Uh...
What?

If the the old shocks lost their gas charge and got aligned at a lower height it will affect the alignment. Just like if the driver is a huger 300+ lb person you have to put ballast weight in the driver seat to properly set alignment.
We're talking about shocks here, not struts.


What I'm talking about has nothing to do with it being shocks or struts. Learn about alignments.

 

[KingCake]

Originally Posted By: 03cvpi
I had to replace some OEM front shocks in an 05 crown victoria, the left front shock was completely dead (no gas or oil) and the other still fine. We replaced them with Bilstien HD Performance shocks. Before the shocks were replaced the left side was low by 1/16 of an inch or 0.0625, after replacement the car was almost level. Within 1/32 of an inch. The left side was the low side after shock replacement, probably due to loss of spring tension by driving on a dead shock absorber for a few thousand miles. The work order was for an alignment, but the dead shock caused the vehicle to feel like it was out of alignment, we replaced the shocks, checked the alignment and sent the car on it's way. I've personally never had to re-align a vehicle after shock replacement, but I suppose it could happen.


Only if the car had an alignment at the lower ride height. Then you'd need to redo it.

 

[gallydif]

Originally Posted By: gallydif
The wierd thing is the first 2 miles I drove was fine and then it went down hill from there. Became worse. Like if something loosened up.

Sorry if there any confusion. Those 2 miles are in reference to when I was driving it home from the shop originally. Not after checking the lug nuts and taking it for a test drive.

 

[gallydif]

It ends up that my front driver side tire had a belt separation and there were little metal wires coming out. When I took it off, the tire in the shape of an egg. Now time for a new tire... or 2