Annoying rattle after new suspension
08-17-2011, 11:27 AM
#1
Thread Starter
Join Date: Feb 2011
Location: IN
Posts: 12
Annoying rattle after new suspension
Hi all, hope you can help me here.
I recently installed pretty much a whole new suspension system in my 07GT. The list is as follows:
Koni Sports (on full soft for now)
Steeda Sport Springs
UMI Poly/roto Lower arms
UMI Roto adjustable upper
UMI poly/roto panhard
I run the stock D/S FWIW.
I installed everything ~2weeks ago and was careful to torque everything to the book (I used http://iihs.net/fsm/?dir=52 for torque values). i even retorqued everything again a week later. What I have now is a very slight rattle that seems to be from the passenger rear when I go over uneven bumps. Even bumps where the L and R move together causes no noise. It has that sound of a loose fastener somewhere but I just can't identify anything loose. The only bolt I wasn't able to torque "to the book" was the upper control arm to the body mount. On that bolt I used a ratcheting box end and picked up most of my body weight (probably 200lbs or so) on the wrench. I really don't think that's going to be slipping.
Anyway, the handling is sharp and the back end is so much more controllable now. But every no and then I'll hear that rattle when driving around and it pisses me off. Nothing is in the trunk, and nothing is under the rear seat. I almost think the spring might rattle a little on it's seat, is that possible?
I reset the pinion angle and the lateral position of the driveshaft to the same measurements it was originally. (pinion was 3 degrees up in front on my jackstands, and the axle was centered on body when measuring the hub to the inner fender wall.) I'm hearing more whine from the axle, but my guess is it's due to the stiffer bushing transmitting more NVH to the body, and not due to anything I've done. Stock rear, stock ratio, royal purple.
Thoughts?
I recently installed pretty much a whole new suspension system in my 07GT. The list is as follows:
Koni Sports (on full soft for now)
Steeda Sport Springs
UMI Poly/roto Lower arms
UMI Roto adjustable upper
UMI poly/roto panhard
I run the stock D/S FWIW.
I installed everything ~2weeks ago and was careful to torque everything to the book (I used http://iihs.net/fsm/?dir=52 for torque values). i even retorqued everything again a week later. What I have now is a very slight rattle that seems to be from the passenger rear when I go over uneven bumps. Even bumps where the L and R move together causes no noise. It has that sound of a loose fastener somewhere but I just can't identify anything loose. The only bolt I wasn't able to torque "to the book" was the upper control arm to the body mount. On that bolt I used a ratcheting box end and picked up most of my body weight (probably 200lbs or so) on the wrench. I really don't think that's going to be slipping.
Anyway, the handling is sharp and the back end is so much more controllable now. But every no and then I'll hear that rattle when driving around and it pisses me off. Nothing is in the trunk, and nothing is under the rear seat. I almost think the spring might rattle a little on it's seat, is that possible?
I reset the pinion angle and the lateral position of the driveshaft to the same measurements it was originally. (pinion was 3 degrees up in front on my jackstands, and the axle was centered on body when measuring the hub to the inner fender wall.) I'm hearing more whine from the axle, but my guess is it's due to the stiffer bushing transmitting more NVH to the body, and not due to anything I've done. Stock rear, stock ratio, royal purple.
Thoughts?
08-17-2011, 11:51 AM
#2
Former Sponsor
Join Date: Sep 2007
Posts: 1,936
It'll be the control arms most likely. Roto-joints are much better than rod-ends, but anything that has a ball riding in races has some play in it and even a few thousandth can cause a similar noise. If you grease them you might find the noise is reduced which will confirm that.
09-12-2011, 01:58 PM
#4
Thread Starter
Join Date: Feb 2011
Location: IN
Posts: 12
Update:
Still need help.
I re-greased all the UMI roto-joints and checked for anything loose. Nothing I could find was loose and/or not torqued well. I changed the rebound on the Koni's to see if it was an issue of being set to full soft, but still nothing.
I'm really at a loss, the roto-joints all seemed nice and tight when I installed them. i am thinking about pulling them out and checking to see if one is loose now that it has been driven and broken in. I get some clunks from both sides, and a rattle from the passenger side.
I'm beginning to suspect something with the springs isn't right. they seemed to slip into place correctly, but maybe I'm silly and didn't do something right. I couldn't determine an up/down orientation on the Steeda Sports, is it possible to install them upside down? It seemed straightforward to slip the new spring in place when I put the axle back in.
Still looking for ideas.
Zach
Still need help.
I re-greased all the UMI roto-joints and checked for anything loose. Nothing I could find was loose and/or not torqued well. I changed the rebound on the Koni's to see if it was an issue of being set to full soft, but still nothing.
I'm really at a loss, the roto-joints all seemed nice and tight when I installed them. i am thinking about pulling them out and checking to see if one is loose now that it has been driven and broken in. I get some clunks from both sides, and a rattle from the passenger side.
I'm beginning to suspect something with the springs isn't right. they seemed to slip into place correctly, but maybe I'm silly and didn't do something right. I couldn't determine an up/down orientation on the Steeda Sports, is it possible to install them upside down? It seemed straightforward to slip the new spring in place when I put the axle back in.
Still looking for ideas.
Zach
09-12-2011, 10:41 PM
#5
Hey Zack.
I just replaced every single bolt-on item in my front and rear suspension. I heard rattling right awat at low rpms and over bumps.
Turns out my exhaust was tapping the driveshaft loop bracket.
It could be exhaust or maybe the emergency brake cable tapping the Lower control arm.
I doubt you will hear rattling from your new hard parts if they are torqued to spec.
I would think you would here more of a creaking sound with your rear end suspension setup.
Does it make the same sound in gear or in neutral?
Also, if your rear is 3 degrees positive that means you do not have any room for upward pinion movement. The end of the tranny is usually around 2.7, 2.8 downward toward the rear.
After many conversations with Steeda and local shops I have the rear at 1.9 upward with a .9 pinion angle negative(downward) having 1 degree in for rear end upward movement.
I just replaced every single bolt-on item in my front and rear suspension. I heard rattling right awat at low rpms and over bumps.
Turns out my exhaust was tapping the driveshaft loop bracket.
It could be exhaust or maybe the emergency brake cable tapping the Lower control arm.
I doubt you will hear rattling from your new hard parts if they are torqued to spec.
I would think you would here more of a creaking sound with your rear end suspension setup.
Does it make the same sound in gear or in neutral?
Also, if your rear is 3 degrees positive that means you do not have any room for upward pinion movement. The end of the tranny is usually around 2.7, 2.8 downward toward the rear.
After many conversations with Steeda and local shops I have the rear at 1.9 upward with a .9 pinion angle negative(downward) having 1 degree in for rear end upward movement.
09-13-2011, 01:26 AM
#6
I still think it could be all those roto-joints, and just because you can't physically feel any looseness doesnt' mean there's no play at all. I had a rod-ended panhard bar and after some decent mileage, it started rattling like a ****. While replacing the rod ends I tried wiggling them and felt no slack. I replaced them with roto-joints and the rattle is 98% gone. In very specific situations I can heard a very slight clunk but its for all intents of purposes silent.
09-13-2011, 07:30 AM
#7
Thread Starter
Join Date: Feb 2011
Location: IN
Posts: 12
Hey Zack.
Turns out my exhaust was tapping the driveshaft loop bracket.
It could be exhaust or maybe the emergency brake cable tapping the Lower control arm.
I doubt you will hear rattling from your new hard parts if they are torqued to spec.
I would think you would here more of a creaking sound with your rear end suspension setup.
Does it make the same sound in gear or in neutral?
Also, if your rear is 3 degrees positive that means you do not have any room for upward pinion movement. The end of the tranny is usually around 2.7, 2.8 downward toward the rear.
After many conversations with Steeda and local shops I have the rear at 1.9 upward with a .9 pinion angle negative(downward) having 1 degree in for rear end upward movement.
Turns out my exhaust was tapping the driveshaft loop bracket.
It could be exhaust or maybe the emergency brake cable tapping the Lower control arm.
I doubt you will hear rattling from your new hard parts if they are torqued to spec.
I would think you would here more of a creaking sound with your rear end suspension setup.
Does it make the same sound in gear or in neutral?
Also, if your rear is 3 degrees positive that means you do not have any room for upward pinion movement. The end of the tranny is usually around 2.7, 2.8 downward toward the rear.
After many conversations with Steeda and local shops I have the rear at 1.9 upward with a .9 pinion angle negative(downward) having 1 degree in for rear end upward movement.
1) I ASSume you mean the center bearing carrier on the d/s. Or did you mean an aftermarket hoop? Anyway I can check again, It seemed to have plenty of clearance from he exhaust to the D/S (LTs into Pypes O/R X). I can shake the exhaust as hard as I can and it doesn't seem to hit anything with the rear axle supporting the weight.
2) E-brake cables, maybe, but this sound like it has more energy than an e-brake cable. I was careful to reroute my ebrake cables along the new arms and ziptied them to the arms. I can check to see if the've been moving around.
3) Agreed, It doesn't seem to me that brand new parts that were nice and stiff going in would rattle 30 miles later (when it started).
4) No creaking. I used to have a squeak/creak with the factory parts and that's one of the reasons I replaced it all. Well at least that's what I told the wife.
5) Yes it'll clunk over bumps in gear under power, engine braking, or with it out of gear. I get the passenger side rattle/knock only when the passenger side hits an uneven bump.
6) Pinion angle: I had to adjust the UCA a few turns to get the pinion raised in front by 3 degrees. I didn't do ALL the measurements because my objective was just to reset it to the starting angle. I made notes of where I measured (right on the label on the bottom). I didn't measure both the pinion and the trans, just the pinion, and then I put it back where it started. So my 3 degrees of the pinion up in front is just that measurement, not the comparative measurement between trans and pinion. Given your tranny measurements that'd put me close to zero pinion angle (ASSuming my jackstands were level). I can recheck my angle to see if that's it as well.
Great suggestions, keep them coming.
Zach
09-13-2011, 08:09 AM
#8
Join Date: Aug 2009
Location: CA
Posts: 43
Hello, I had a rattle after the first time I road raced after my new suspension. It turned out my sway bar had come loose. It wasnt loose enough to feel when I was under the car, but when I was driving I got a big rattle. Just a thought, Good luck. It sucke when you make your car better and end up with anew noise.
