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Crunch Noise Going Over Speed Bumps

by kanling, May 25, 2011



9th gen (2003), in the winter going over speed bumps (slowly) there is a crunch noise as the front suspension travels up and down. I assume that it is the struts, but I can't find anything online that struts make that type of noise when they go bad. Ball joints, etc look okay to my untrained eye and there is no noticeable noise with steering.

The upper strut mounts could be the cause of your noise - sometimes you can see if the mount is bad by prying that rubber plug off the top of the strut mount (right under the hood) - see if it still has some clean grease in there. If the grease is dried out, contaminated, or if there is play in that area - the mount is likely shot.

Another common noise area surround your swaybar - double the bushings that run around the swaybars and the end links that tie the swaybars to the strut body. Usually it is those end links (looks like a mini-dumbbell) that wear out - cannot be greased like the older ones, so when the grease leaks out or dries out - the link is toast. If the rubber bushings hold securing the swaybar are dried out, they can squeak/creak, which can sounds like a crunching noise inside the cabin. Hit them with some silicone lubricant and see if the noise goes away - if it does, then replace those bushings and double check the condition of the other rubber bushings and mounts on the bottom of the car.

Also double check that the major chassis nuts and bolts are secured - check the two large bolts on the strut body (holds strut to steering knuckle), check the strut mount bolts (three of them), check the strut bolt (under the rubber cap), check the tie-rod ends, balljoints and wheel bearing (have to lift the tire off the ground, wiggle tire see if there is any play)

I checked all of those items without finding any obvious culprit. But, the boots over the struts are torn up, so the struts have no protection. If the struts aren't bad now, they will be someday.

So, I'm going to go ahead and change the struts and strut mounts. Since I have to take off the stabilizer links to do that, I'm going to go ahead and replace those too.

Will see what happens and report back.

You may want to look into replacing rubber bushings with urethane bushings. They won't wear out like rubber, are stiffer, and — if I remember correctly — are self-lubricating? Just wanted to throw this into the mix as I've replaced bushings on other cars I've owned with their urethane counterparts, and what a difference in overall handling and comfort they made!

I finally got around to changing the front struts, which I knew was going to be a big job and it was. I have some comments to write up and on parts quality from a few manufacturers. But, I will do that later. Unfortunately, now I have a clunking noise coming from the suspension area when turning and going over small bumps while turning.

I don't get it on the road when the wheel is only turned a bit, but only in parking lots where the wheel is turned more significantly. Strangely, the noise comes when first setting off, but after driving for a few minutes, I will not have the noise when returning to another parking lot. Very strange.

I did my left front strut first and did some test driving before changing the right one. I got the noise at that time. I thought that maybe I didn't have the upper spring seat mounted correctly, so I took the left strut out and completely reassembled it at the same time I put the right one in. I'm pretty sure that I got the struts put together right. I am wondering if the difference in the struts from old to new is bringing out some other problem like a bad sway bar bushing or something. I did change the sway bar links at the same time as the struts.

I will have to take another good look under there, but I was pretty careful on reassembly after hearing the noise the first time.

I can't even say for sure where the noise is coming from. I think it is from the left strut area, but a passenger today thought it was coming from the right side... so maybe it is in the center.

Since you already changed the end-links and struts, has the sounds changed slightly - got better or worse from the first time around?

Since the noise is more apparent when turning, I'd look into the condition of the axles (make sure there isn't excessive play, torn boots), tierod ends, lower ball joint, bushing on control arm, or even the engine/transaxle mounts.

The problem was the tightness of the sway bar link nuts. This was causing the clunking or popping noise. These two nuts apparently have to be super tight.

(I spent a good hour with the car jacked up trying to figure out where the noise was coming from and couldn't figure it out. I finally gave up and had to take it to a shop because I have to have the car ready. They were perplexed, too. But, once on the lift they found that the nuts could take a little bit more tightening.)

It does seem like the new struts have quieted the original noise, but we'll have to see in colder weather to be sure.

The new struts have definitely tightened up the handling. I am getting much less roll going around curves and a less bouncy ride. The old struts clearly were worn out. I will add a little more commentary on the project in a week or so.

OK, here are some comments on changing the struts. Some bolts were way harder to loosen than I expected. I think it took me over 4 hours and a lot of frustration for each side. If you ever attempt this job, I would strongly recommend allowing enough time so that you can do the job over several days so that you aren't in a rush. Next time I need to change struts, I will probably just go to a shop. They will have it easier since they have a lift and air tools (and torque wrenches if they use them). I just had jack stands and a decent set of sockets and wrenches. Anyway, I learned a lot.

I changed the struts, strut mounts, and the sway bar links. I figured that as long as I had to take those things apart, I might as well change them because the cost of the parts is a lot less than the time and effort to do the job again.

The biggest recommendation that I would make is to break the top nut loose on the struts before you do anything (even before jacking up the car). Don't take the nut off, just break it free. Getting the nut loosened once the strut is off and the spring is compressed is a huge pain.

For the sway bar links, you only have to take one end of the sway bar link off (the end that attaches to the strut) to change the strut. The nut is a pain to remove because it is torqued like crazy, somewhat corroded, and it tends to spin the ball joint on the link rather than remove the nut. There is a 6mm inset in the stud to keep the joint from turning, so you need a 6mm Allen wrench end for your socket set. Unfortunately, it is way too easy to strip that 6mm inset because it doesn't go very deep and is full of crud. Use on old toothbrush to clean out the crud before even starting. You think you are halfway done when you remove the end of the link that attaches to the strut. If you are taking off the other end that attaches to the sway bar, I think it was five times more difficult. The nut is facing the opposite direction (away from you) and there is less room to work. On one side, I spent two hours trying to get this think off. The hex inset stripped and I had to resort to big vise grips and ruining the grease seal. I almost had to resort to a hack saw.

The two big bolts that attach the bottom of the strut to the steering knuckle are not as hard to remove as you would think, but you still need a nice long breaker bar and maybe a hammer.

The three mounting nuts that attach the struts to the body are easy.

I used a loaner spring compressor from my local auto parts store to compress the spring and disassemble the strut. My recommendation would be to take your time and use care in reassembly. The strut top plate needs to be reinstalled so that the wider part is facing the outside of the vehicle, so make sure you know the proper orientation before disassembly. I didn't do any wheel alignment like some people recommend. I will watch my tire wear, but I don't see how the alignment could have changed significantly.

Bolt sizes are:

Brake line bracket 14mm

Swaybar link 17 mm (6 mm hex inset)

Steering knuckle bolts 19 mm

And here are some comments on the parts I used...

Struts: I used KYB.

Strut mount: I first ordered Moog brand, but when they arrived, the two were different. They were the same fitment, but the manufacturing was completely different. Even though it is probably okay, I wanted both sides to match perfectly. So, I then ordered KYB. Same thing happened (two different!) and I found that KYB and Moog were sharing the same exact designs anyway. So, it appears that all the brands are just using the same contract manufacturers and you get whatever happenes to be the cheapest contract at the time. So, for the mounts, I would recommend buying on price, not brand.

Bellow: I got KYB, but I wasn't really happy with the quality. The plastic is really rigid and I suspect it will crack after a number of cold winters. The bellows also don't have a top spring seat like the OEM bellows and the seal is not very good. So, I got a set of Moog bellows. I opened the box and found that the Moog bellows were identical to the KYB except for the box. And the higher price. So, I ended up just keeping the KYB. I actually used the top part of the OEM boot that had the spring seat and stretched it over the top of the new boot. The OEM boot was shredded from rubber degradation, but the top part was still okay. The bumper is not pre-installed in the bellow and is a real pain in the --- to install in the slot. I recommend getting the bellow and bumper ready to go before starting work, because you don't want to spend the 20 minutes it takes to get the stupid bumper installed after you just spent a lot of time fighting with stuck bolts.

Sway bar links. I used Mevotech because they were half the price of others and appeared to be just as well made. Of course, given the problems that I had with noise, I wonder if maybe I would have had an easier time with another brand. Hard to tell. (Even with the nuts re-tightened, I do still occasionally get a noise, but I can live with it and probably wouldn't have noticed it if I didn't have the initial problems.)

Spring seats. I changed the lower spring seats. These are the rubber pads that the spring sits on at the bottom end of the strut. I changed them because I assumed that the rubber on the OEM seats would have gotten brittle over the years. The only brand I could find was Monroe. The replacement seats were decent enough, but not as beefy as the OEM. And, it turns out that the OEM seats were still in really good shape.

  • 149 posts

Thanks for the update. Good info.



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