rear suspension rattle

pass1over

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I've about had it with this rattling from my rear suspension. Turn's out it was two different rattles, one of them I fixed, the other ...

The bushing's in my panhard bar were totally shot, so I replaced it and it solved that rattle.

I recently (last weekend) replaced the bushing on the top of the rear-end housing with a poly prothane unit. The stock rubber unit was totally worn out. I figured this was the cause of my sounds and replacing it would solve my problems. The rattle was totally gone for about a day or two, then it returned.

I hear it when going over bumps or it rattles like crazy when going down my rock/hard pan driveway. Everything's tight, i've checked it numerous times. When messing with the upper arm for the bushing install, the sounds it was making were very similar to what I hear when driving. I also hear the sound emanating from the center of the rear seat.

Did i just not get the bolt tight enough? Didn't check with a torque wrench, just got it tight as I could. Maybe the bushing on the chassis side of the upper arm is worn out?

Steeda adj. upper control arm w/ poly bushing, Steeda upper control arm mount, prothane housing bushing, Steeda billet lower control arms, J&M steel adjustable panhard.
 

07 Boss

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The rear arm bolt is like 85 or 89 ftlbs and the front is a bunch, like 130 ftlbs. The front one takes a little grunt to get it that tight. Too tight is an issue to. Also was the suspension loaded when you torqued down the bolts?

Could be a lot of things back there but I would start with inspecting the sway bar bushings and end links first.
 

pass1over

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I torqued the arm to the mount off the car because the value was so high, I didn't think I could do it when the mount was installed.

Suspension was not loaded when I torqued the upper arm bolts, don't know if there's enough room to get in there without it hanging down somewhat.

Rear sway bar links looked fine, I disconnected them to let the rear suspension fully hang down.
 

BMR Tech 2

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End links are a common cause for rattles/clunking, especially on the 11+ cars. I have a ton of customers always calling looking for replacement end links.

Another thing to check is the flag nuts for the panhard bar. I actually had the flag come loose on the nut and it was rattling around on my own personal car. It took a few weeks of swearing before I realized what was happening.

Go over all the hardware and make sure it's all torqued to spec, and make sure your exhaust isn't bouncing off of anything.
 
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JEWC_Motorsports

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Suspension has to be loaded to correctly torque down the bolt, if not you are putting the poly in a bind and it is going to wear pretty quickly. I used a torque wrench to tighten mine, had plenty of room.
 

pass1over

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I'll try to torque it while it's under load this weekend. How much load has to be on the suspension? My car's pretty low and if I put the weight of the car on it, the upper arm is so far up in there I cant get a wrench on it. Does it just need to be not free hanging?

Will check out the endlinks on the rear swaybar as well. Am I just looking for cracking in the bushings? Anything else in particular?

Closest thing exhaust comes to is the panhard support bar, and it clears it by about an inch or so. I'll check the flags as well to see if their rattling, but from my recollection, they were all still attached. The flag nuts that are still there at least. I've replaced some of the hardware during suspension install.

If I shake the car side to side while under it (supported on stands and chocked) I can isolate the noise to the upper arm. At least, it was last time I attempted this. Like I said, it seemed as though this bushing has fixed it. Maybe it's just not torqued enough.

Thanks for all the assistance so far.
 

Senna1

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Mods list says you have a Steeda upper arm w/ poly bushing too? Is it possible that bushing is shot? Or the loss of compliance from the housing mount moving from rubber to poly caused you some binding that wasn't there before and you're hearing the results of that?
 

pass1over

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I did not inspect the bushing on the Steeda Upper arm when I had it apart, but I will when I get under there again this weekend. At least i'm getting real good at taking the rear suspension out of the car now. Just wish I had my new workshop and two-post lift already!

I have the exact same rattle still, even after the housing mount was replaced to poly as when it was rubber.
 

pass1over

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Tried shaking thing's under the car and it seemed the noises were coming from my sway bar links. Replaced all of the swaybar bushings with a poly set from Energy Suspension. The rattle persists.

Noticed this morning, if i'm sitting in the drivers seat with the engine off, I can wiggle/move my weight side to side in my seat hard and make the car produce the noise.

Guess i'll see if I can get my wife to recreate it so I can listen from under the car.
 

bujeezus

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Sure it's not the seat? Sorry couldn't help myself. One thing I've learned over the years is the sound isn't always coming from where you think it coming from and can steer ya in the wrong direction. Case in point, my mom brought over her little Suzuki Esteem and said a funny noise was coming from the passenger side. I jacked it up thinkin it was her cv joint but everything looked good. I told her keep an ear out an if it gets worse take it to our local trusted mechanic. It turned out to be the driver's side cv joint that was on it's way out.
 

frank s

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Way back in the day a coworker parked her car and walked to work because of a startling noise from below. She asked me to check it out. Zeroed in on the driver seat area. Looked underneath the seat and retrieved a teaspoon. Rattle solved.
 

pass1over

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wasnt the seat as I could grab the fender and make it create the same noise.

I think I may of fixed the problem though. I did a couple thing's last night, so not sure which one it was.

There were little plastic caps on the spring perch on the axle side, the spring isolater goes on top of them. They seemed loose and pointless, so I removed them.

Speaking of spring isolater's, their a bit worn out and I might need a new set, drivers side one was a bit squished on one side and the coil-over adjustment collar might of been rubbing/rattling on the spring perch.

Also, I noticed that the sway bar was ridiculously close to the BMR relo bracket on the driver side, so I clearanced the bracket some to give it some more room. Can't even use the damn things anyways, might as well take them off.

But, it seems as though the rattle is mostly gone, might still be there a little bit which makes me lean towards it was the bar rattling on the relo bracket? and it just need's a bit more massaging.
 

pass1over

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also, was thinking otw back to work from my chiro appt., with all this poly and super stiff suspension and such, should I just expect a little bit of noise from the rear? Am I overly obsessing about something I don't need to be?
 

pass1over

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I have the Steeda adjustable upper arm and the Steeda HD mount, as I said above.

I called Steeda to try and get this answer, but the guy on the phone was stumped and said he would have someone call me back .... we all know how that works out ...

Do you use the stepped spacers/washers for the arm if your using the Steeda mount as well? OR are the washers just for use on the stock mount?

If you do use them on the Steeda Arm/Mount combo, can you see these washers on the chassis side when installed? I don't think they're on the car and that might be causing the rattle.

I'd rather not have to take it apart twice, to verify no washers and then to put washers in, if I don't have to.
 

redfirepearlgt

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Is this a 12? If so double check the ball slip joints on the axle back exhaust. If they are loose they will thump up under the back end when loading and unloading (throttle and letting off). Won't always happen. Just pulling down on the muffler tips won't reveal it. Get under and push up on the exhaust at the slip joint. May not be your problem but turned outto be my rattle. BTW I am running all poly bushing LCA's, UCA, panhard, and springs from BMR and have zero issues aside from normal increased NVH due to the harder bushing material. No rattles or bangs.
 

pass1over

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Thanks for that. I'll check them out/snug up the connections when I'm under there next.

This one i'm sure is from the upper arm, just need to know about that stepped washer. Still haven't heard back from Steeda.
 

pass1over

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It appears as if it's my sway bar end links. If i correct them to horizontal under the body mount, I get to rattle. But after driving, the swaybar sides like to creep towards the outside of the car.

They end up looking like this / \ rather than | |

Is there a way to stop this from happening? Was going to take rear sway off just to verify that this is what's making this damn racket I can't get rid of.
 

stpete

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If you have something banging around over bumps, replace the sway bar bushings and end-links or end-link bushings first. They're cheap and it's the solution a significant amount of the time. You can just remove the sway to verify it's the problem. They usually look fine. This applies to all cars/trucks/suvs.
 
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pass1over

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sorry, forgot to post that. Have already replaced the end link bushings with poly one's. Energy Suspension I think.
 

KonaMustangGT

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I've had repeated clunking from the rear drop link bushings, but they didn't move from horizontal. My attempt to install the Energy Suspension bushings was unsuccessful, so I went another path. Did you torque the drop links to chassis bolts at ride height while links were vertical?
 

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