There is a 'thud' in the rear when I go over even the smaller bumps with my 2005 R53 Cooper S. Not a rattle, a solid 'thud' or 'bump.'

I have jacked up the rear, and done the following without luck. What else should I be looking for?

• Checked wheels for vertical/horizontal play: Nothing
• Checked heat panel(s) for movement: Nothing
• Checked (by hand) my lower control arms: Nothing

Thanks in advance, guys.

 

Check the swaybar mounts. The rubber bushings in them wear out.

 

Bushings r a good call as well as a blow strut allowing the the control arm to hit the bump stop and thud.

 

Is there a way to do this without taking the load off of the wheel(s)?

Dorothy is far from her garage right now.

 

No, you would need to use a spring compressor and remove the strut, then compress the strut by hand to see if the strut recoils. A very general rule is the effective life of a strut is around 70k miles, sometimes less or more.

 

I am doubting my that thud is a bad strut. This sucker thuds under the lightest bumps, as well as the gapping pot holes.

Am I able to test my sway bushes for the click without taking the load off the wheel(s)?

I'm going to go rock the car side to side and see if I can replicate this annoyance...

 

Any suspension mods?

 

JCW shocks & Alta Lower Control Arm. Pretty basic.


I checked the end links and sway mounts...everything is tight. Except the bushing looks suspicious...what do you guys think? Culprit?

 

I can't find the replacement bushing anywhere. It's like the internet has mis-labeled all rear bushings as front, and front bushings as rear.

What all "rear' bushings look like, which look nothing like the photo I have posted above.

 

When I had that happen it was a loose rear strut at the top mount point.

 

+1 on the rear strut nut. I chased this noise for a while - had the same symptoms as described. Eventually used a spring compressor to help crank down on the strut nut while the spring was compressed.

 

Found the problem: Posting a photo to help others that are searching for answers.

Summary: Rear Sway Bar bushing needs to be replaced. See below for a quick fix.

(You'll need to log in to see the photo)
The sway bushing has become compressed over time. You'll need to replace this, or, follow the photo. There is a slit in this bushing, which makes it easy to slide it on and off of the sway bar. You can cut this slit wider, which allows for the metal U-Bar to grasp the sway bar tighter, giving you no movement.

 

Similar problem: a rattle at low speeds over rough, irregular pavement. Sway bar bushings were worn/replaced; but the rattle persists. Don't know what to do next.

 

edit:

I need to read more closely.

 

I hav this same exact problem! She drives me crazy!! (pun intended)

 

I had the same problem on both front and rear sway bar bushings. It seems the bushing material deteriorate over time or sooner than other car.

With new sway bar bushings all clunking or thumbing noise gone.

 

Reply to Ministrater: Rattle (low speeds on rough, uneven pavement that wrenched/tweaks suspension) was repaired as follows: "Found sway bar links (left and right) worn; knock from rear axle going over bumps; replaced rear swaybar links (left and right). No noise present after installation". So far, so good.