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post #1 of 21 (permalink) Old 02-18-2012, 12:59 PM Thread Starter
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Knocking in rear

Lately I have this issue that came up...going over bumps I have this slight knocking sound coming from the rear suspension, and I also hear the same sound when accelerating from a stop, say, from a stop sign. Swaybar links and mounts are fine, I can't see anything else in the rear suspension that is loose or looks out of place...all I can figure is that my rear shocks are really worn, and need replacement, they are high milage KYBs that have been through a harsh life of cut springs...any suggestions on other things to check? This is a new sound I have never heard before, and it was hard to even figure out where it was coming from at first.

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post #2 of 21 (permalink) Old 02-18-2012, 01:35 PM
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idk i was geting a loud knock back there turned out it was my shock . it was hanging off, and my driver rear shocks was loose .replace them see what happens and go from there.
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post #3 of 21 (permalink) Old 02-18-2012, 03:40 PM
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Let that guy out of your trunk, Earl?


































Had to be said!

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post #4 of 21 (permalink) Old 02-18-2012, 03:45 PM
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Check the top shock bushings.

Just thought of this Earl, if you have a rear shock tower brace make sure it didn't come loose.

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post #5 of 21 (permalink) Old 02-18-2012, 04:36 PM Thread Starter
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Good call on the RSTB....would the rear shock bushing kit from SCP be the item I need to replace?

I just looked over all the bolts attaching the shocks to the upper mount, along with the bolts attaching the RSTB, all look fine.

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Last edited by Earl; 02-18-2012 at 04:47 PM.
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post #6 of 21 (permalink) Old 02-18-2012, 05:20 PM
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Well I wouldn't replace anything that looks ok. There's only so many moving parts in the rear end they're just a pain to track down sometimes. My SC makes a weird rear suspension noise somewhat like you described but the whole suspension is pretty much shot so no help there.

I would get a bright flashlight and get underneath it, make sure all of the bushing look good before you start replacing anything.

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post #7 of 21 (permalink) Old 02-18-2012, 05:23 PM
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Could also be the toe link compensators, any of the bushings in the upper/lower control arms or the knuckle bushings. That's what I'm going thru with mine.

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post #8 of 21 (permalink) Old 02-18-2012, 06:53 PM Thread Starter
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Well, this goes back a bit further, actually...I should have given more detail...

Back in october, the car got a new passenger side rear hub and bearing, a few days after replacement, I was pulling onto the highway, under hard accel, I hear a loud "BANG!" from the rear of the vehicle, somewhere. Pulled over, looked, all seemed to be fine.

From that point forward, these issues started, nothing seems wrong, everything "looks" as it should....

I did a bit of searching, bad toe compensator links sounds like a definate possibility, OR bad/going bad differential mount(s)

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Last edited by Earl; 02-18-2012 at 07:03 PM.
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post #9 of 21 (permalink) Old 02-19-2012, 08:17 AM
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Maybe a Bolt will help!


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post #10 of 21 (permalink) Old 02-19-2012, 10:55 AM
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My car had a noise when going over bumps when I bought it. Problem turned out to be a swaybar end link bushing was shot. So I replaced both sway bar end links just for good measure :-)

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post #11 of 21 (permalink) Old 02-19-2012, 09:39 PM
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Quote:
Originally Posted by Earl View Post
Well, this goes back a bit further, actually...I should have given more detail...

Back in october, the car got a new passenger side rear hub and bearing, a few days after replacement, I was pulling onto the highway, under hard accel, I hear a loud "BANG!" from the rear of the vehicle, somewhere. Pulled over, looked, all seemed to be fine.

From that point forward, these issues started, nothing seems wrong, everything "looks" as it should....

I did a bit of searching, bad toe compensator links sounds like a definate possibility, OR bad/going bad differential mount(s)
If something went "BANG!", then something "BROKE!", find it and replace it.

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post #12 of 21 (permalink) Old 02-19-2012, 10:43 PM
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Axle nut tight?

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post #13 of 21 (permalink) Old 02-20-2012, 12:48 AM
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Ive got the same problem and for a while the handling has been a bit funny, I think it might even be responsible for my car oversteering and fishtailing into that sign during my evasive maneuver a couple weeks ago.

Ima inspect everything tomorrow....

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post #14 of 21 (permalink) Old 02-20-2012, 12:51 PM
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Quote:
Originally Posted by MAIC View Post
Maybe a Bolt will help!

I had my rear mount on the 94 bolted and it broke on me at the track. IIRC, it cracked and ripped right by where it bolts to the frame. I got a ride home, grabbed the mark VIII rear mount and put it on at the track, drove home Thank goodness the rear cover didnt break. I dont think I am going to bolt them anymore!

I would jack up the rear of the car and wiggle things to see what is loose. Something is broken or loose if its making a sound like that, I would presume. Good luck! The rear mount might be something to look at for cracks, just for fun.

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post #15 of 21 (permalink) Old 02-20-2012, 01:44 PM
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Quote:
Originally Posted by Earl View Post
Lately I have this issue that came up...going over bumps I have this slight knocking sound coming from the rear suspension, and I also hear the same sound when accelerating from a stop, say, from a stop sign. Swaybar links and mounts are fine, I can't see anything else in the rear suspension that is loose or looks out of place...all I can figure is that my rear shocks are really worn, and need replacement, they are high milage KYBs that have been through a harsh life of cut springs...any suggestions on other things to check? This is a new sound I have never heard before, and it was hard to even figure out where it was coming from at first.
If a visual inspection does not find the problem, the best way to diagnose this complaint is to unload the weight bearing componets of the suspension.

1) Jack up rear, and support with jack stands. The rear wheels off the ground about 4-5 inches. (It is not recommended to lift the car from the differential on an IRS.)

2) Place floor jack under spring, and lift to compress the spring under the weight of the car, but don't lift the car off the jack stands.

3) With a long lead pipe, say about 4.5-6 feet in lenght, 3" o.d. or so, place one end of the pipe under the tire, and lift the tire up and down using the pipe as leverage. It helps to have an assistant while you go under, and look for parts that are moving in excess: worn or broken bushings, bolts, shocks, links, springs etc... Listen for any grunts, squeaks, knocks, etc...And the tire should move up and down without any binding.

4) Repeat on other side.

This procedure is also used to diagnose worn ball joints on the front.

Lee.

Last edited by leegrady; 02-20-2012 at 01:49 PM.
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post #16 of 21 (permalink) Old 03-11-2012, 05:28 PM
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Quote:
Originally Posted by Earl View Post
Lately I have this issue that came up...going over bumps I have this slight knocking sound coming from the rear suspension, and I also hear the same sound when accelerating from a stop, say, from a stop sign. Swaybar links and mounts are fine, I can't see anything else in the rear suspension that is loose or looks out of place...all I can figure is that my rear shocks are really worn, and need replacement, they are high milage KYBs that have been through a harsh life of cut springs...any suggestions on other things to check? This is a new sound I have never heard before, and it was hard to even figure out where it was coming from at first.
Did you ever find the issue? I had the same irritating knocking noise coming from mine. I ended up replacing the inner lower control arm bushings and toe link compensators and it's gone. It's nice to drive around without that knocking now!

Mike
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post #17 of 21 (permalink) Old 03-11-2012, 07:29 PM Thread Starter
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I haven't taken any time to look into it, but it is getting worse, I'll have one of the techs at work look at it...I'm just hesitant to dump any money into the car right now, too many other financial obligations right now...I'll have it looked it, if it's nothing dangerous, it's just gonna have to wait.

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post #18 of 21 (permalink) Old 03-11-2012, 07:37 PM
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Originally Posted by Earl View Post
I haven't taken any time to look into it, but it is getting worse, I'll have one of the techs at work look at it...I'm just hesitant to dump any money into the car right now, too many other financial obligations right now...I'll have it looked it, if it's nothing dangerous, it's just gonna have to wait.
I had a clunk in mine, and it was the two nuts you see in that picture (post #9) were loose. I've also had a clunk when the sway bar links were worn out.

You're just gonna have to get it on a lift and start checking things out.

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post #19 of 21 (permalink) Old 03-11-2012, 08:36 PM
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I had a clunk in my rear suspension. Turned out to be the front diff bushings were shot

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post #20 of 21 (permalink) Old 03-11-2012, 08:52 PM
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I had a clunk in my rear, turned out that I didn't hit the guy hard enough before I put him in the trunk!!!

Honestly it was the sway bar links as well. I just couldn't resist lol.
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post #21 of 21 (permalink) Old 03-11-2012, 09:14 PM
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I had a clunk in my rear, turned out that I didn't hit the guy hard enough before I put him in the trunk!!!

Honestly it was the sway bar links as well. I just couldn't resist lol.
Post #3 Ralph beat you to it

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