Brake pedal causing clunk in suspension - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Dexman1349 · 08-27-2014, 07:31 PM

There seems to be a weird clunk coming from the rear suspension when the brakes are applied. One clunk when first applied, another when released. There are no other noises coming from the suspension during any other driving. It's like something pops into position when braking then pops back.

It sounds the same whether something is in the trunk or if everything is removed.

I have gone over the rear suspension a dozen times with my wrenches, even going so far as to remove the strut/spring assembly to check they are tightened too. Caliper bolts are tight. Problem is that I can't reproduce the sound anywhere other than on the road.

The noises only occur when the car is moving forward.

intensifi · 08-27-2014, 10:36 PM

check your caliper bolts

Avenging Orange · 08-28-2014, 12:24 AM

I had a clunk/slapping sound on mine when I applied brakes. Found out it was the brake pads. Took em out and greased up the back side of the pads. Quiet as a church mouse now.

Dexman1349 · 08-28-2014, 06:22 PM

I'm thinking it's time to replace brakes. Can anyone say CTS-V big brake upgrade? (and yes I know the rears are the same, but I'll be replacing all 4 rotors and pads with the new front calipers).

Dexman1349 · 09-05-2014, 11:08 AM

Something is jacked with my UCA bushings.

Got the car up on the lift last night and with the help of a couple friends found that my entire rear axle assembly was moving up to 3/4" when the brakes are pressed. All of that movement goes through the UCA bushings. The bolts are as tight as I can get them, so I will order a new set.

I'm not sure the old set is broken, but having the new set there when I drop the cradle will help make sure this is something I only have to address once.

Avenging Orange · 09-06-2014, 03:15 PM

Hmmmm. Maybe I should dig a little deeper.

Rico · 09-06-2014, 03:16 PM

I get a clunk when I back up sometimes.

Dexman1349 · 09-11-2014, 12:01 PM

Replaced the UCA bushings last night (big shout out to the guys at JDP for the quick response to my order).

Comparing the old (left) with the new (right):
Passenger side:

Driver's side:

You can see how much more snug the inner ferrule is on the new ones. The inner ferrule on both is not where it's supposed to be and the bushing immediately around it looks damaged. The view from the other side is worse (no pics of that).

Anyways, new ones installed. Clunk is still there, although it seems to be significantly reduced.

One of my local Camaro club friends suggested it may have to do with the order in which things were installed. I put the "main" bolt in first to connect it to the UCA, then installed the side mounting bolts. However, on the driver's side I had to loosen the main bolt about 1/2" because I couldn't get the mounting bolts to line up. I don't believe anything is cross threaded, but because I had to torque the bracket into place with the main bolt loose, there is a chance the inner ferrules aren't lined up properly and the UCA is actually binding up inside the bushing. This would explain why all the bolts seem tight until something the suspension is under a specific load.

I will re-try installing everything tonight. On one hand, I've gotten really good at dissembling/lowering/reassembling the rear suspension quickly, on the other hand I really don't want to do it again... dammit.

Avenging Orange · 09-11-2014, 01:04 PM

Wow, pretty big gap in the second pic. Im still clunkless after using the brake greas/adhesive on my pads. But I think I have one more winter project to add to the list. Good luck and keep us posted.

Dexman1349 · 09-12-2014, 02:19 PM

I gave up and took it to a shop. Hopefully they find what's wrong because I sure as hell couldn't.

GMteSSted · 09-12-2014, 02:22 PM

check out this thread, may need these washers installed:

http://www.camaro5.com/forums/showthread.php?t=225109

Dexman1349 · 09-12-2014, 03:15 PM

Shop said the passenger trailing arm is moving again.

KaBoom1701 · 09-12-2014, 04:50 PM

Noise from parking brake actuator?

JusticePete · 09-13-2014, 10:53 AM

Sorry I read this after most of your work was completed Dexman. The Z/28 OE upper rear control arm is the best available solution at this time.

You may want to check this OE bushing in the upper rear control arm. It is a factory seal monoball, just like this in the rear knuckle. The OE bolt is a shouldered bolt. They use the shoulder design to prevent the bolt from rust-welding to the inside of the ferrule. That should loads the top of the ferrule. I broke mine testing at Gingerman.

The load generated crossing the turtle backs shattered the ferule.

You can see the wear pattern on the bolt shoulder.

A new Z/28 arm with a Z/28 bushing and a full shouldered 10.9 bolt are a robust solution.

08-27-2014, 07:31 PM	#1
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	Brake pedal causing clunk in suspension There seems to be a weird clunk coming from the rear suspension when the brakes are applied. One clunk when first applied, another when released. There are no other noises coming from the suspension during any other driving. It's like something pops into position when braking then pops back. It sounds the same whether something is in the trunk or if everything is removed. I have gone over the rear suspension a dozen times with my wrenches, even going so far as to remove the strut/spring assembly to check they are tightened too. Caliper bolts are tight. Problem is that I can't reproduce the sound anywhere other than on the road. The noises only occur when the car is moving forward. __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build Last edited by Dexman1349; 09-11-2014 at 12:02 PM.

08-27-2014, 10:36 PM	#2
intensifi Drives: '12 2LT Convertible Join Date: Mar 2012 Location: Belmont, California Posts: 1,701	check your caliper bolts __________________ Mods: GM Locking Gas Cap, RS License Plate Frame, SS Brembos, ZL1 FrontEnd, 14/15 Convertible Top

08-28-2014, 12:24 AM	#3
Avenging Orange Drives: 2010 Inferno Orange 2SS/RS Join Date: Apr 2010 Location: Clermont, IN Posts: 3,297	I had a clunk/slapping sound on mine when I applied brakes. Found out it was the brake pads. Took em out and greased up the back side of the pads. Quiet as a church mouse now. __________________ 2010 Inferno Orange 2SS/RS M6 Black Leather, Sun Roof, OBX Headers, Borla touring axle back, Cold Air Inductions CAI , non synthetic fluids, BMR total bushing upgrade/1" lowering springs, DSE 32mm rear sway bar. GM fe4 shocks/struts/LCA's, AAM 3.91 diff, Vertini RFS1.8 20x9 +30. Conti ExtremeContact Sport 275/35/20. sjm autoprod ABL dash kit. Mike Norris tuned 413/419. Avenging Orange: 43 years of not buying into the Hype........and damn proud of it!! https://youtu.be/9JD9it6SmB8 https://youtu.be/xmelTlEzI34 KICKING CANCERS ASS SINCE 2015!!

08-28-2014, 06:22 PM	#4
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	I'm thinking it's time to replace brakes. Can anyone say CTS-V big brake upgrade? (and yes I know the rears are the same, but I'll be replacing all 4 rotors and pads with the new front calipers). __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build

09-05-2014, 11:08 AM	#5
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	Something is jacked with my UCA bushings. Got the car up on the lift last night and with the help of a couple friends found that my entire rear axle assembly was moving up to 3/4" when the brakes are pressed. All of that movement goes through the UCA bushings. The bolts are as tight as I can get them, so I will order a new set. I'm not sure the old set is broken, but having the new set there when I drop the cradle will help make sure this is something I only have to address once. __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build

09-06-2014, 03:15 PM	#6
Avenging Orange Drives: 2010 Inferno Orange 2SS/RS Join Date: Apr 2010 Location: Clermont, IN Posts: 3,297	Hmmmm. Maybe I should dig a little deeper. __________________ 2010 Inferno Orange 2SS/RS M6 Black Leather, Sun Roof, OBX Headers, Borla touring axle back, Cold Air Inductions CAI , non synthetic fluids, BMR total bushing upgrade/1" lowering springs, DSE 32mm rear sway bar. GM fe4 shocks/struts/LCA's, AAM 3.91 diff, Vertini RFS1.8 20x9 +30. Conti ExtremeContact Sport 275/35/20. sjm autoprod ABL dash kit. Mike Norris tuned 413/419. Avenging Orange: 43 years of not buying into the Hype........and damn proud of it!! https://youtu.be/9JD9it6SmB8 https://youtu.be/xmelTlEzI34 KICKING CANCERS ASS SINCE 2015!!

09-06-2014, 03:16 PM	#7
Rico Flying da helicopter Drives: Black SS/RS Join Date: Oct 2009 Location: HI Posts: 1,215 View My Garage	I get a clunk when I back up sometimes.

09-11-2014, 12:01 PM	#8
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	Replaced the UCA bushings last night (big shout out to the guys at JDP for the quick response to my order). Comparing the old (left) with the new (right): Passenger side: Driver's side: You can see how much more snug the inner ferrule is on the new ones. The inner ferrule on both is not where it's supposed to be and the bushing immediately around it looks damaged. The view from the other side is worse (no pics of that). Anyways, new ones installed. Clunk is still there, although it seems to be significantly reduced. One of my local Camaro club friends suggested it may have to do with the order in which things were installed. I put the "main" bolt in first to connect it to the UCA, then installed the side mounting bolts. However, on the driver's side I had to loosen the main bolt about 1/2" because I couldn't get the mounting bolts to line up. I don't believe anything is cross threaded, but because I had to torque the bracket into place with the main bolt loose, there is a chance the inner ferrules aren't lined up properly and the UCA is actually binding up inside the bushing. This would explain why all the bolts seem tight until something the suspension is under a specific load. I will re-try installing everything tonight. On one hand, I've gotten really good at dissembling/lowering/reassembling the rear suspension quickly, on the other hand I really don't want to do it again... dammit. __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build

09-11-2014, 01:04 PM	#9
Avenging Orange Drives: 2010 Inferno Orange 2SS/RS Join Date: Apr 2010 Location: Clermont, IN Posts: 3,297	Wow, pretty big gap in the second pic. Im still clunkless after using the brake greas/adhesive on my pads. But I think I have one more winter project to add to the list. Good luck and keep us posted. __________________ 2010 Inferno Orange 2SS/RS M6 Black Leather, Sun Roof, OBX Headers, Borla touring axle back, Cold Air Inductions CAI , non synthetic fluids, BMR total bushing upgrade/1" lowering springs, DSE 32mm rear sway bar. GM fe4 shocks/struts/LCA's, AAM 3.91 diff, Vertini RFS1.8 20x9 +30. Conti ExtremeContact Sport 275/35/20. sjm autoprod ABL dash kit. Mike Norris tuned 413/419. Avenging Orange: 43 years of not buying into the Hype........and damn proud of it!! https://youtu.be/9JD9it6SmB8 https://youtu.be/xmelTlEzI34 KICKING CANCERS ASS SINCE 2015!!

09-12-2014, 02:19 PM	#10
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	I gave up and took it to a shop. Hopefully they find what's wrong because I sure as hell couldn't. __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build

09-12-2014, 02:22 PM	#11
GMteSSted Drives: 2018 ZL1 1LE Join Date: Nov 2009 Location: Tennessee Posts: 877 View My Garage	check out this thread, may need these washers installed: http://www.camaro5.com/forums/showthread.php?t=225109

09-12-2014, 03:15 PM	#12
Dexman1349 2010 2SS/RS M6 Drives: 2010 2SS/RS M6 Join Date: Jun 2010 Location: Auckland, NZ Posts: 1,482	Shop said the passenger trailing arm is moving again. __________________ 2/7/2014: 419 hp, 419 tq Cosmetic: ZL1 front w/mailslot, painted stripes, powdercoated SS rims, tow hook, and full chrome delete Suspension: Pfadt subframe bushings, Pfadt rear UCA bushings, Z28 Upper control arms, Spohn trailing arms with BMR trailing arm & differential bushings, ZL1 Toe Rods and springs, Prothane radius arm inserts & steering rack bushing, Pfadt Sport front sway, FE4 conversion w/ DS rear sway, Pfadt strut brace Drivetrain: RMCR tune, CAI intake, Kooks headers, hi-flo cats & exhaust, VMAX TB, ZL1 fuel pump, LSR Tri-Ax shifter Bumblebee Racecar Build

09-12-2014, 04:50 PM	#13
KaBoom1701 KaBoom1701 Drives: 13' ZL1 Red M6 Join Date: Dec 2012 Location: I.E. SoCal (Yucaipa) Posts: 8,630	Noise from parking brake actuator? __________________ Mods: Roto-Fab Intake, WW Res. kit & Big Gulp Air Scoop, Elite Catch Can, ATI Super Damper & 18% OD Pulley, LF Idler pulley bracket, Metco CC breather, ID850 Injectors, Stainless Power Headers w/ ceramic coating, TR71X Spark Plugs, JMS Fuel Pump Booster, Bo White TB, Tuned by Ted @ Jannetty Racing, Ron Davis HX, D3 Reservoir, Pfadt 1" Springs, Moreno Camber Plates, ZL1 Addons Splitter guard washers, Tow Hook kit & rock guards, Hurst Shifter Billet Plus 6 Speed Short Shifter, ZL1 DRL lighting harness, ZL1 Recaro Seats.

09-13-2014, 10:53 AM	#14
JusticePete Drives: Camaro Justice Join Date: Jun 2007 Location: Virginia Posts: 20,174	Sorry I read this after most of your work was completed Dexman. The Z/28 OE upper rear control arm is the best available solution at this time. You may want to check this OE bushing in the upper rear control arm. It is a factory seal monoball, just like this in the rear knuckle. The OE bolt is a shouldered bolt. They use the shoulder design to prevent the bolt from rust-welding to the inside of the ferrule. That should loads the top of the ferrule. I broke mine testing at Gingerman. The load generated crossing the turtle backs shattered the ferule. You can see the wear pattern on the bolt shoulder. A new Z/28 arm with a Z/28 bushing and a full shouldered 10.9 bolt are a robust solution.