Hi All,

I have a 2009 Impreza base model.  I had to replace a wheel stud on the passenger front side while putting on new summer rims, so I decided to do all of them while the car was lifted. No issues with the new studs going in. I now have vibration/shaking as I accelerate into 35+km/hr.  When I brake I don't feel vibration in the brake pedal, so I don't think rotors are warped. Could the wheel studs not be seated properly in the hub? Could the wheel be off balance?  Has anyone had this issue before after changing studs? 

Dave

First, I always remember if it's not broken don't fix it!

Studs don't fail and are not a regular maintenance item. 

Did you properly torque the lug nuts?  You may have damaged the hub flange.  Details on the removal and installation process you used would help.

To install the studs, I start the insert with a stud tool and nut to pull the stud into the hub.  A few of them I wacked a few times from behind with a hammer.  Shouldn't have affected the hub since the hub withstands way more force on turns and the street.  Maybe I don't have the studs seated properly or could be the lug nuts as you said.  Additionally I noticed that the front tires are larger than the back tires (rims are all 17 inch). 

If I understand correctly, in addition to changing the studs you’re running a different set of wheels and tires? If that’s the case, then the tires are probably out of balance. Also it’s not a good idea to have tires that are different diameters.

I'm going to put the smaller tires on the front and the bigger tires on the back and see if that makes a different.  Also will take to a shop to make sure they are balanced. 

you are going to have a problem with your differentials eventually.

The computer will see the wheels rotating at different speeds and try to correct the imbalance.

the center differential will suffer. AWD systems in general should not be run intentionally with different tire sizes.

12 hours ago, DaveD said:

Hi All,

I have a 2009 Impreza base model.  I had to replace a wheel stud on the passenger front side while putting on new summer rims, so I decided to do all of them while the car was lifted. No issues with the new studs going in. I now have vibration/shaking as I accelerate into 35+km/hr.  When I brake I don't feel vibration in the brake pedal, so I don't think rotors are warped. Could the wheel studs not be seated properly in the hub? Could the wheel be off balance?  Has anyone had this issue before after changing studs? 

Dave

 

Tires probably need balanced. But, so we aren’t guessing so much:

How positive are you this symptom did not exist before you worked on it?  We don’t want to assume it’s the studs if it’s not.

do the tires need balanced?

What brand and how old are the tires?

Why did a wheel stud need replaced? 

If it’s an open nut, look at the captive depth of each stud in the center of the nut. Are they all the same depth?

If it’s not an open nut - are they all seated fully?

 

Tires should be the same size with even wear.  The max Dia. difference is 10%.

On 8/2/2024 at 8:51 PM, lmdew said:

Tires should be the same size with even wear.  The max Dia. difference is 10%.

10%? That seems way too large a difference.