mikelexF

Hey guys I seriously need your help on a problem I have been having for a while.

I'm running19x10 +38 wheel in the rear 275/30/19 tires on my 2011 F. And for over a year now i have been hearing what appears to be a knocking in the rear driver suspension ONLY when driving over pretty deep bumps/ potholes.. I didn't think nothing of it since i try avoiding bumps and potholes as much as possible.

I know my wheel/tire setup is kinda aggressive but this does not happen on the passenger side.. So recently I went to Lexus to have it checked and they determined that the driver side rear shock was blown and replaced it under warranty. BUT the knock is still there and I cant figure out what it could be. Another thing I noticed is that the wheel gap on the driver side rear seems to be less than the passenger side rear. And there is some rubbing on the driver rear tire too.

Any help would be appreciated. thanks in advance

Evil Teo

iTrader: (13)

u will probably need to shave your fenders or cut them if the tires are rubbing in the back. is the sound more like a thump? it could be the cause of the springs slapping against each other when its going over bumps and potholes. i get that from time to time with my BC coilovers but not all the time.

mikelexF

Yeah its like a thump/thunk sound... the tire is rubbing too (only the driver rear side) mine also only does it on extreme bumps and potholes.
Im running a stock suspension setup with a higher offset wheels. My biggest concern is i already had a shock failure on the driver rear suspension and had it changed last week... Im not sure whats causing the the sound since the passenger side doesn't rub or makes that sound.

Evil Teo

iTrader: (13)

how many miles do u have on the car and how many miles do u have with those wheels on?
it could be a list of things but can't really pin point it. try bringing it back to them and have a test drive with the tech so they can hear it.

mikelexF

i have 20000 km (12000+ miles aprox) on the car. I got the wheels soon after i got the car and the new shock absorber put in last week. If both sides were rubbing and making the noise i would understand but the passenger side is perfect even over the harshest road conditions but driver side is not.. I even thought maybe because of me being in the car that was causing the one side to have more weight but even when parked, I can definitely see that the driver side rear fender gap is a little less than the passenger side.. If the culprit was tire size irregularity, i would gladly change it... i was just wondering if the forum had any better opinions on the matter.

RCB

iTrader: (18)

My car rubs more on the passenger side rear then the drivers side with stock suspension. Use a paint marker to mark the spring coils, fender lip ect. A rub will make a scrapping noise. Does it do it going straight or with cornering load?

mikelexF

That's very odd that yours rub on the opposite side... no rubbing on cornering load... just on straight bumps/potholes... And the suspension noise only happens on potholes or roads that are raised and has a lip.

Bulls23337

iTrader: (2)

Wonder if you're hitting the bump stops??

mikelexF

I dont think its the bump stops As i mentioned before the shock absorber was replaced, so if the bump stop was compromised, i would think that lexus would have replaced it too...I hope.

Supraman16

iTrader: (5)

Check your sway bar end links. I had a issue like this on my Supra and turned out the sway bar end links were shot. Easiest way to do it is to disconnect the end links and drive around (carefully) and see if the knock is still there. If it's not, you've found the cause!...Darshana S...

mikelexF

I doubt it but i wont leave it out.. I just had the f sport sway bar installed and my mechanic didn't say... but not to rule it out i will check again when i go back to see him this week.

RCB

iTrader: (18)

I was thinking swaybar links as well. Did the noise exist before the install?
My car rubbed due to 305s with stock suspension and no fender mods.

SC400slide

iTrader: (11)

With something so new, i doubt there would be suspension problems.
Could be as simple as plastic dust cover wacking the wheel.
Just my 2 cents

Evil Teo

iTrader: (13)

so u install the f sport sway bar...it could be the endlinks that is making the sound.

mikelexF

yeah the noise was there before the install... I will check the links again when i see my mechanic


I bet u it is something real silly.. I hope it is..Don't want to replace another shock..