Solved: Clunk in Rear Suspension (2008 Yaris 3-door)

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Over the past year or so, my Yaris made a "clunk" noise every time it rode over a bump in the road. The clunk was coming from the rear of the car.

At first, I thought it was due to some odds and ends that I had stored in those compartments located under the floor in the hatch area, where the spare tire sits. So, I wrapped up everything in bubble wrap and lined all the plastic-to-plastic contact points on the compartment lids with weatherstrip tape. No success.

Then, I thought the clunk may be coming from either the exhaust system or the rear suspension, so I put the car up on jack stands to take a look. I tried tightening the lug nuts, shook the exhaust system back and forth, pulled in and out on the wheels to see if any bushings were shot. I also checked my after-market TRD anti-sway bar to see if it was interfering with the twist beam rear axle. I could not replicate the noise. Again, no success.

The clunk seemed to be getting worse, and in addition, the car seemed to be riding harder than before. It was the middle of January, freezing outside, and snowing all the time. So, finally I relented. I went to my local Toyota dealer.

They found the problem. One of the rear shock absorbers was leaking, and because the body of the shock was not completely filled with fluid, the plunger in the shock absorber body was not submerged in fluid in the first inch or so of its travel. Thus, the "clunk".

The Toyota dealer replaced the rear shocks in my Yaris. The clunk is completely gone and the car rides like new again. I would have never been able to figure this out on my own.