Most of these items were replaced due to wear, a few to try and "fix the noise". The clunk can be heard from the front end over the smallest of bumps. It's heard more than felt, if that makes sense. Don't really feel it in the steering wheel or brake pedal. -Complete left and right front strut assemblies with springs and mounts. -Left and right sway bar links. -Left and right sway bar bushings. -Left and right ball joints. -Left and right inner and outer tie rods. -Left and right control arms. - Left and right CV axles. Tomorrow I'm going to check for loose bolts at the k-frame and control arms.
Can you feel it at all in the steering, rocked back and forth with someone feeling different areas on the front cross member and chassis and the steering rack itself? T1 Terry
Clunks can also be silly things like a chunk of loosely fastened plastic bouncing up and down. Check the license plate, bumper cover, the plastic shields underneath the engine compartment, the wheel well liners, and the fuse box lid. Check that all parts of the air intake are properly assembled. Check that the hood latches down tightly. Grab both sides of the front edge of the hood and see if it can be moved up and down on either side. (Rubber mount may have moved or fallen off one side.)
If it were control arms you'd be having vibrating steering wheel when braking. Replaced the control arms in wife's 2011 ES350 to fix steering wheel vibration and didn't tighten down the rear mounting bolt on the control arm. Vibration came back soon and I found it by jacking up the front end and pry barring things til I heard the clunk. If your Prius is high mileage try swapping out front struts. Strut swap got rid of the clunks I was having on my Accord. Plus it makes the ride a little nicer. They're not crazy expensive and the job isn't all that tough.
That's a thought, as a mechanic in my own workshop, loose cartridges in front struts occurred every so often, as well as loose valve bodies in OEM struts. Hard to diagnose when the spring is still loading the strut, but once it is compressed, the clunk can be felt when moving the strut cap up and down .... T1 Terry
I found a few things that all could be causing it, as well as a bad wheel bearing. The brand name was "TRQ" and it has less than 500 freaking miles on it. Grease was slinging out of it. The whole knuckle has a lot of material loss. Personally I think aluminum is a terrible choice for a steering knuckle because it's softer than steel and thusly wears easier. The lower control, the nut would not fully tighten again once it was removed, there are some issues with the threads, caused either by the nut or some kind of factory defect. You can see where the nut sat, the threads are much shallower. The 2 bolt holes for the strut on the knuckle have started to lobe out, again aluminum is a poor choice for this. You'd think Toyota would of been smart enough to install steel sleeves for this area. Here's what a new one looks like.
What is the rusted steel part in the 4th photo? That certainly shows signs of constant impact .... T1 Terry
