Chrysler 300M Enthusiasts Club
  • Squeaking Noise from rear end

  • Discussions on suspension & steering repairs or upgrades.
Membership Banner

Discussions on suspension & steering repairs or upgrades.

Moderator: Moderators

User avatar
 #386874  by sdugasjr
 
Hello all, I am having some trouble that I am hoping you guys can help me out with because this is becoming one gigantic headache. For some context, I am going to give you the entire backstory leading up to now.

When I purchased my car, I needed some rear struts done as they were beginning to fail and cause the rear end to bounce excessively, as failing struts do. I ordered a set of KYB Quick-Strut Plus' from RockAuto, I know that quick struts are not recommended on these vehicles but it was what I could afford. About a month ago, I then took the struts and the car to the dealer to have them installed, at this time (pre-installation) the car was silent, did not make a single clunk, squeak, or chirp from the rear end. The dealer has to "cut out" the rear links because they are "too rusty to remove" and charges me 200$ to get them ordered with no extra labor charge since they were already in there to replace the struts, fine. The car was there for about 4 days when I finally got a call that it was finished, so I picked the car up, as I was leaving their driveway I hear an awful squeak/chirp noise upon hitting a bump, from the rear end. Of course, this is after the service center's closing time so I can't go in there and have somebody ride with me to hear/explain what noise it is making. I continued on down the road to find that it was still making that noise, so I drop the car off AGAIN and email the service manager about the issue I was having and she said they would look at the vehicle the next day. They take a look at it the next day and tell me that everything was torqued to spec and that they didn't seem to hear a squeaking noise, rather a clunking noise (which I would rather listen to, than the chirp) and they tell me it is coming from my rear sway bar bushings. So, I take them on their word and ordered some poly bushings. I just had them replaced recently (by myself with help from you wonderful people on the forum) and my noise still persists, I am done dealing with the dealership and having them tell things that need to be replaced to get rid of this noise, just for them to not even be the correct things.

Sorry if that was too long to read but, my question to you guys (and gals) is, what would be making this noise, and how on god's earth can I fix it? I really enjoyed the quietness of this car while driving and I can no longer enjoy that because of this issue. I was reading some previous threads on here and people were saying that the top mount bushing could be causing the squeak or chirp noise I am hearing, but how can I check that without ripping the entire back deck apart?

Again, sorry if that was way too much to read just for me to get to the point. I could also try to get a video of the noise it is making while driving tomorrow, to better help you guys help me.

Thanks in advance,
Sidney
User avatar
 #386877  by Sneke_Eyez
 
Posting a video will help us help you for sure.

You said you did quick struts, so there's less chance of issues with the top nut of the strut not being tight enough.

I'd just guess they didn't tighten something down all the way.

I'd bring the car back there and make them fix it - you replaced the rear swaybar bushings and the car is still making the noise.
User avatar
 #386879  by sdugasjr
 
Here is the video:


I have planned on taking it back up to them at some point, just have to find the time of when because it’s going to take them a few hours to “look the car over” (and not do anything) and my car is my daily.
 #386883  by cos1776
 
From your video, it sounds like the noise is inside the car. Can you produce the noise with the car stationary and you bouncing it? If so, you could pull the rear seat and have someone bounce the car while you try to locate the source of the noise, and if it is perhaps only one side it is coming from. Definitely sounds like something loose with it clunking, and maybe the "chirp" or "squeak" could be two metal pieces rubbing together.
User avatar
 #386885  by sdugasjr
 
I was bouncing the car yesterday and the only squeaks I heard were from the poly bushings (they were light squeaks, not like what was in the video) and the clunking is probably from the gap between the bushing and the sway bar because for some reason my sway bar is slightly smaller than the smallest bushings offered by PB. Also it sounds like it is both sides, while driving down the road I think I can hear it alternate between sides depending on the side the bump is on.
User avatar
 #386887  by In-trepid
 
There are basically four possible problem areas.
1. The sway bar/bushings: The new bushings should be extra tight on the sway bar. There are two different sizes of sway bar on these vehicles. A 3/4" sway bar on base models and I'll say most Specials with 17" wheels and a 13/16" sway bar on Specials with 18" wheels. You probably have the 3/4" sway bar. If you ordered your bushings from Johnny at polybushings.com, he should have asked you which size you needed. It sounds like you got 13/16" bushings instead of the 3/4' bushings. They should also have come with green slimy lube that is necessary to use with the polyurethane bushings. This is a must. What you can do is to remove the sway bar and end links completely from the car. Put the (rear) long bolts back in and torque them down. The car can be used without the sway bar. If the squeaking goes away, it is the sway bar bushings or end links causing the problem.
2. Sway bar end links: These generally will cause a clunking noise. The have rubber or poly bushings at the top and need to be torqued to the recommended specs both on top at the strut and on the bottom at the sway bar. If you didn't replace them when you did the struts, now might be a good time to do so.
3. The lateral links: Based on your description of they had to cut them out, I'd guess that the lateral links were replaced. These need to be left lose and only torqued to spec at both the inside bolts and at the long 14" bolt when the car is sitting with the suspension under load. Failure the do it this way could cause an issue with the preloading of the bushings which could cause the bushings to become lose and rotate in the lateral link causing squeaking. This is not a common problem, but could be your issue if they were not preloaded properly when replaced and torqued down.
4. Struts: While I haven't heard in any problems with rear KYB quick struts, that doesn't mean that you didn't get a bad one. With some struts, it seems that the top center bolt isn't torqued down sufficiently or the threads are too short to torque it down far enough. That seems to be resolved by putting a thick washer between the strut mount and the nut. This is easily accomplished with the car on the ground and the suspension under load. You will need a strut nut tool to do this and you will need to take out the back seat and package deck. You can also check that the three top mounting nuts are tight as well.

This is about all there is to check for the rear suspension. it is pretty simple on these cars.
User avatar
 #386888  by sdugasjr
 
If I got the 13/16" then it was by mistake because I told him 3/4", and even put it in my PayPal invoice when I sent the money over.
Pretty sure the dealer replaced sway bar links, not too sure on lateral links (and to be very honest I have no clue what they are).
The struts were going to be my next place of blame, I have some chassis ears that I planned on putting on the car to see where exactly this noise is coming from.
User avatar
 #387388  by sdugasjr
 
Okay, I took the car back to the dealer last week to see if they would fix their mistake, they actually assessed the car and listened to the issues I was having this time, and narrowed it down to bad strut mounts in the rear, on both sides. They even took the car out with the rear sway bar removed (links and all) to make sure that wasn't even a factor. This gave me indication that it was a bad install because the chances of getting 2 bad struts from the same factory is slim to none. I also resolved my sway bar bushing issue by driving to Illinois to pick up some bushings from a dealer down there, to correct that noise. I got the struts warrantied out through Rock Auto and had the dealer install them, they called me yesterday and told me that the car was all set and they only heard a clunk noise from the front (front sway bar links that I already knew made noise) and asked me if I wanted to test drive it to see what I thought. I went up there today to test drive the car and the noise is suppressed significantly, but it still makes the same noise but it seems from only the left side, the service manager rode with me and even confirmed the same thing.

My question to you fine people is, has anybody had any issue with the KYB quick struts on the rear? Or is the installation not being done properly? I don't know what else it could be, I left the car with them to see what they could do, so far they have replaced rear sway bar bushings, rear sway bar links and this is now my second set of struts from KYB. Please let me know your guys' thoughts on this situation.

Thank you,
Sidney
 #387389  by StealthM
 
Hey Sydney. I have been running the KYB struts on all for corners of my 2000 M and haven't had any issues. I know quite few members run these struts without issue. Only thing is that it is recommended that you use factory mounts and bearings. I just use the KYB strut alone and used all mopar mounts and bearings... good luck hope this helped a little.
sdugasjr liked this
User avatar
 #387392  by sdugasjr
 
StealthM wrote: February 24th, 2021, 1:44 pm Hey Sydney. I have been running the KYB struts on all for corners of my 2000 M and haven't had any issues. I know quite few members run these struts without issue. Only thing is that it is recommended that you use factory mounts and bearings. I just use the KYB strut alone and used all mopar mounts and bearings... good luck hope this helped a little.
Did you use factory mounts on the rear as well? And the only issue with that is I would have to order new OEM mounts for the rear since the dealer tossed out my factory struts the first time they did the install :/
User avatar
 #387393  by In-trepid
 
I've had pretty good luck with the KYB quick struts in the rear. Up front, I do as Clarence suggested and use factory mounts and bearings. I guess that the next thing I would try is factory rear strut mounts.
sdugasjr liked this
User avatar
 #387394  by sdugasjr
 
In-trepid wrote: February 24th, 2021, 9:56 pm I've had pretty good luck with the KYB quick struts in the rear. Up front, I do as Clarence suggested and use factory mounts and bearings. I guess that the next thing I would try is factory rear strut mounts.
Do you have a source to some that are reasonably affordable? I seen some on eBay for 150 a piece and the dealer wants to charge me 300+ each.
 #387396  by StealthM
 
Sydney. I was able to get the OEM mounts from my dealer at a decent price because he was happy to get them outa stock. I was only looking for fronts because the rear ones don't ware as quickly. No steering rotation I guess. But he had them so I grabbed them up. Ebay is your best bet. For OEM and the price is just that for OEM. Next option is a lower mile salvage. Good luck Mr. Phelps..
 #387397  by StealthM
 
Ok I just watched your video. You might have more going on then the strut bearing. Usually when a bering goes bad its kinda like a muffled thump thump. That's like squeaking and thumping. At this point I would look at ALL my bushing back there. What else was replaced back there.
User avatar
 #387405  by sdugasjr
 
StealthM wrote: February 25th, 2021, 1:44 am Ok I just watched your video. You might have more going on then the strut bearing. Usually when a bering goes bad its kinda like a muffled thump thump. That's like squeaking and thumping. At this point I would look at ALL my bushing back there. What else was replaced back there.
That video was prior to my most recent visit. The noise is much quieter now, the dealer said that it sounds like something isn't seating full, so I am going to try John's recommendation of putting thick washers in there to see if it will clear up any space.
I had the struts done, they replaced the sway bar links while they were in there, because supposedly they had to cut them out; and I did sway bar bushings. In the video, the sway bar bushings were too big and when they replaced the struts this last time, I went out and got the correct size bushings and had them put them in.
 #387409  by cos1776
 
Check the torque of the top center nut of the strut. As John suggested, if it is not torqued to spec, it can cause the type of noise you describe. Ask me how I know this!! LOL!
 #387410  by StealthM
 
Good. I know the issue with the strut being a bit too long and using washers to fix it but I believe that wasn't the case with the KYB's I am pretty sure it was with the Monroe quick struts. And I believe it effected the fronts only... but you never know....
User avatar
 #387414  by Steve From MA
 
Defiantly the upper rear strut mount/s I've gone thru this - my rears still squak when they're really cold (before the car warms up)
sdugasjr liked this