Problems after replacing struts

[Hyundaihoney09]

I recently got my struts and shocks, along with some other components of the suspension replaced. It has been about a full month since then.
Right after that I noticed a sound (clunk or like something is loose) coming from the front passenger side (right side) of my car after going over speed bumps (when it's really noticeable), over smalls potholes, turning left, and uneven roads. I brought this up to them and they looked everything over and said it looked good. They suggested replacing the stablizer links, so I ended up getting the sway bar links and bushing replaced. The noise was still there. They said it is most likely the bushings, but they're new so I'm confused.

I decided to look at the struts a few days ago and I noticed they look different. Could anyone familiar with struts confirm if they are indeed different brands? They look like it to me. Also, could this be the reason why there is a noise coming from the right side? I assume it isn't wise to use different brands for the front struts.

This is a 09 Hyundai Sonata.

 

[Lubener]

The spacing of the coils at the spring's bottom on the right side sure look much closer together than the left side. Perhaps the right side spring is bottoming out making the noise.

 

[D60]

Can't tell from the pics, but differing brands would not cause a clunk. The jounce bumpers maybe look different, but that means nothing and those only come into play if you're landing the General Lee.

If you truly have a clunk they should be more concerned. They're likely using crappy quick struts and while they didn't build the part(s), they should eat it, warranty the part(s) and file a labor claim with their supplier. Sucks but it happens

 

[Marcozi]

If a shop did the work I'd take it back and have the shop check it out.

 

[D60]

Apparently such noises are -- or were around 2008-2010 -- rampant when these cars were new. There's talk of Hyundai revising the struts, but I can't find details of what was done.

You might take a really deep dive into this:
https://forums.edmunds.com/discussion/7516/hyundai/sonata/hyundai-sonata-front-suspension-thunk/p9

At least two report the revised struts helped but fell short of a panacea.

Muddle through the bickering and keyboard warriors, quite a ways in there's an example of something that sounds like your experience, kinda:

"I bought a used 09 Sonata GLS with 21K miles on it a couple weeks ago. It is a pretty amazing car for the money--lots of room for people and cargo, decent handling (for the price), decent gas mileage, and a nice interior. However, it has the dreaded "thunk" everyone seems to be mentioning. Let me go on to say, based off reading the multiple posts, no one can really explain in words what the "thunk" sounds like. Mine sounds like what one of those small plastic playskool balls hitting and then rolling inside a deep bowl.

I drove it over every conceivable piece of roadway to see what made it make noise. Apparently, it really only "thunks" over roadway with depressions enough to let one wheel drop lower than the other (usually the passenger side), and then only at low speeds (10-20mph). It took awhile for me to replicate it for the dealer, but once I did, the tech immediately said, "Yep, we need to fix this." He went on to explain that in some Sonatas, there is a strange phenomena that causes some of the struts to make a lot of noise--I didn't argue, but I didn't completely understand. He also mentioned that Hyundai has modified their struts due to some of the complaints, so the new ones aren't like the old ones. What's different? I'm not really sure. I also don't understand how "some" Sonatas can have that problem, or why no one understands the issue?

Fortunately, the Hyundai warranty was still in effect, so I got both front struts replaced for free. It has done a lot to dampen the thunk noise, but honestly the noise is still there. The steering has improved though, because there is less vertical movement in the front wheels.

As with other posts, I agree, that if you have considerable weight in the passenger seat (another person of some size (200lbs) or a lot of stuff) the thunk almost blends with the typical suspension noise you hear in other cars--a muffled bump. I think I'm hypersensitive to the old thunk, so I can still make it out. I'm thinking that it's either caused by lousy suspension design, or maybe it is a series of bad struts.

Whatever the cause, I'm still driving the car--I spent enough money not to get rid of it again without some usage. Perhaps when the warranty is gone, I'll trade it for something else. However, for $15K for the complete package (car w/bluetooth, tags, registration, taxes), I still think I got a good deal. The tech says that even with the thunk noise, it was mostly a cosmetic (sound) issue. The old struts were still within spec for compression and extension distance."

There's mention of part #54611-3K680 which appears to still be valid. You might ask your shop if they'd swap those in if you pay the difference in parts. That said, no guarantee this would help.

 

[Bottom_Feeder]

Those castle nuts and cotter pins don't look right.

 

[Hyundaihoney09]

If a shop did the work I'd take it back and have the shop check it out.

Yeah, I will have to do this. I've gone back like 3 times and mentioned the noise and they keep telling me it looks good. After a month of hearing the noise, what's one more time. Thanks.

 

[Hyundaihoney09]

Apparently such noises are -- or were around 2008-2010 -- rampant when these cars were new. There's talk of Hyundai revising the struts, but I can't find details of what was done.

You might take a really deep dive into this:
https://forums.edmunds.com/discussion/7516/hyundai/sonata/hyundai-sonata-front-suspension-thunk/p9

At least two report the revised struts helped but fell short of a panacea.

Muddle through the bickering and keyboard warriors, quite a ways in there's an example of something that sounds like your experience, kinda:

"I bought a used 09 Sonata GLS with 21K miles on it a couple weeks ago. It is a pretty amazing car for the money--lots of room for people and cargo, decent handling (for the price), decent gas mileage, and a nice interior. However, it has the dreaded "thunk" everyone seems to be mentioning. Let me go on to say, based off reading the multiple posts, no one can really explain in words what the "thunk" sounds like. Mine sounds like what one of those small plastic playskool balls hitting and then rolling inside a deep bowl.

I drove it over every conceivable piece of roadway to see what made it make noise. Apparently, it really only "thunks" over roadway with depressions enough to let one wheel drop lower than the other (usually the passenger side), and then only at low speeds (10-20mph). It took awhile for me to replicate it for the dealer, but once I did, the tech immediately said, "Yep, we need to fix this." He went on to explain that in some Sonatas, there is a strange phenomena that causes some of the struts to make a lot of noise--I didn't argue, but I didn't completely understand. He also mentioned that Hyundai has modified their struts due to some of the complaints, so the new ones aren't like the old ones. What's different? I'm not really sure. I also don't understand how "some" Sonatas can have that problem, or why no one understands the issue?

Fortunately, the Hyundai warranty was still in effect, so I got both front struts replaced for free. It has done a lot to dampen the thunk noise, but honestly the noise is still there. The steering has improved though, because there is less vertical movement in the front wheels.

As with other posts, I agree, that if you have considerable weight in the passenger seat (another person of some size (200lbs) or a lot of stuff) the thunk almost blends with the typical suspension noise you hear in other cars--a muffled bump. I think I'm hypersensitive to the old thunk, so I can still make it out. I'm thinking that it's either caused by lousy suspension design, or maybe it is a series of bad struts.

Whatever the cause, I'm still driving the car--I spent enough money not to get rid of it again without some usage. Perhaps when the warranty is gone, I'll trade it for something else. However, for $15K for the complete package (car w/bluetooth, tags, registration, taxes), I still think I got a good deal. The tech says that even with the thunk noise, it was mostly a cosmetic (sound) issue. The old struts were still within spec for compression and extension distance."

There's mention of part #54611-3K680 which appears to still be valid. You might ask your shop if they'd swap those in if you pay the difference in parts. That said, no guarantee this would help.

Thank you for this. It does sound similar to what I'm experiencing, especially when the passenger side drops lower than the other. I find it odd that with the original parts this noise wasn't an issue, but after replacing it the noise appeared. I will look through the thread. I appreciate your help!

 

[Hyundaihoney09]

The spacing of the coils at the spring's bottom on the right side sure look much closer together than the left side. Perhaps the right side spring is bottoming out making the noise.

I hadn't noticed that until I read your reply. In your opinion, would the spacing alone indicate different brands? I was under the impression both sides should be interchangable, hence be the same brand in order to maintain consistent handling.

 

[Hyundaihoney09]

Can't tell from the pics, but differing brands would not cause a clunk. The jounce bumpers maybe look different, but that means nothing and those only come into play if you're landing the General Lee.

If you truly have a clunk they should be more concerned. They're likely using crappy quick struts and while they didn't build the part(s), they should eat it, warranty the part(s) and file a labor claim with their supplier. Sucks but it happens

Thank you for your response. I will most likely take another trip to this shop and have them take a look at it again. I don't believe they really looked into the quality of the parts when I took it back but rather looked for other possible reasons the car could be making a noise. As was mentioned in another comment, the sound also happens when one side (passenger) is lower (and sometimes higher) than the other side. It's unfortunate this wasn't an issue with the original parts but began after they replaced them.

Since you mentioned how the jounce bumpers look different, would this be an indication of different brands? I would prefer for both sides to be the same, so I would like to be able to tell them about it when I go. They do offer a 12 month warranty with their work, so I'm hoping everything will be covered.

 

[Nukeman7]

Your photos appear to show either two completely different struts or two different brands of struts. Based upon a few quick online parts searches, your 2009 Sonata should use the same strut part on both the left and right front positions. If you can get the shop to replace them, I'd suggest going with MANDO MSS050013 struts since they are OEM suppliers for Hyundai.

 

[D60]

Since you mentioned how the jounce bumpers look different, would this be an indication of different brands? I would prefer for both sides to be the same, so I would like to be able to tell them about it when I go. They do offer a 12 month warranty with their work, so I'm hoping everything will be covered.

Not necessarily. Aftermarket manufacturers change things all the time and it's possible one strut was built Nov '24 and the other May '25.

Any indy will tell you it's not uncommon to get two identical part numbers with different visual attributes.