just had all 4 shocks replaced now i’m having a problem with noise inside the cabin over bumps from the rear

the rear shocks now make loud metal on metal noise when going over speed bumps and ride quality from the rear over bumps does not feel correct

parts used: OEM shocks (2) OEM bump stop (2) the only part I did not replace was the top shock mount could this be the source of my problem?

car details: 2012 ls 460 rwd swb 44k miles


edit one more important thing to note the noise comes from the rear left / when bouncing the rear left side of the car shock is very hard to compress

 

Did you get new or used parts? If read right and read left sides require different amount of force to compress, there could be a problem with one of the shocks.

 

rear left is hard to compress when pushing down on the car rear right is much easier on compression and does not make any noises over bumps

the shop is saying it’s my shock mounts but prior to installation of new shocks the noise was not present. they have taken everything out for inspection and have stated everything visually looks fine but the top mount could be the culprit

all parts purchased from Bell Lexus scottsdale both shocks are brand new and oem from dealer

prior to new shocks the rear left side of the car did not take bumps well this leads me to believe it indeed could be shock mount but I do not understand how that stops compression

 

Even a dealer can mistakenly send the wrong parts. I believe there's a right and left shock, different part numbers. If they are correct, replacing the top mount makes sense.

 

good suggestion before the new mounts are installed new vs old part numbers will be compared

after new shocks compression feels extremely smooth on good roads but any time the rear compresses hard on bumps the issue arises

 

Though shock mounts can make noise, I do not see how it has anything to do with stiffness difference.

 

Parts source? Suspected china involvement.

 

Your part numbers for RWD non-air suspension should be:
RR - 48530-80386
RL - 48540-59055

With Mark Levinson:
RR - 48530-80567
RL - 48540-59085