Car pulls (unstable) under acceleration / deceleration (not on brakes) - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Z28-TX · 12-20-2020, 01:45 PM

Just brought the Z-28 out of hibernation since COVID hit. New Goodyear F-1's just installed and new brake pads.

After taking the car a burnish the brake pads run I noticed a weird sensation. The car feels like it's pulling (feels like from the real, yet not certain) under acceleration and deceleration. A good poke of the throttle or quick release of the throttle and I get this sensation. I would not feel confident on track ... it's that pronounced. This is a new one for me, what should I be looking at first?

Thanks!

SIM GhostrdrZ · 12-20-2020, 02:21 PM

When I run into issue(s) after work performed. I always backtrack;
Check tire psi, check wheel lug nut torques, check for dragging brake pads( multiple ways and possible fluid flush/bleeding)
Check for loose suspension or blown shock( the multimatics have little bronze bushings that act as “breathers”, check those are in place)

SIM GhostrdrZ · 12-20-2020, 02:24 PM

This is what the shock fittings look like. It’s a stretch but just a thought.

AustexaSS · 12-20-2020, 03:07 PM

So prior to running the burnish procedure the perceived issue was not noticeable? Is the car pulling to one side constantly? You may have a collapsed brake line. i.e. if the car pulls left under braking the drivers side brake lines should be looked at. You may also need to look at rebuilding a caliper or multiple calipers as one could be sticking if the problem is constant regardless of weather you are applying pressure to the brake pedal. You could also do the brake burnish procedure again and see if this clears up the issue. If you have never flushed the brake fluid it is time to do so regardless. Jack the car up and check each wheel rotates freely and there are no signs or sounds of dragging between rotor and brake pad.

SS Performance · 12-20-2020, 04:11 PM

If it happens on both acceleration and deceleration I would suspect suspension/bushing issues.

How many miles are on the car? Sometimes sitting for extended periods of time can cause bushings to deform.

SIM GhostrdrZ · 12-20-2020, 05:36 PM

Either direction it takes you. Let us know what it is or give us all more details.
Good luck

pzero · 12-21-2020, 11:14 PM

Man hope you find the problem. Let us know and report back please.

This sound stupid but check if rims are in right place. Front 19x11 and rear 19x11.5. If rear is on front it will rub on inner struts. Just check....

MIKZ28 · 12-23-2020, 06:58 AM

I had this very same sensation when I had a right rear tire go flat and put on a spare tire from a 2010 Camaro SS. ( 20x9 ) The different tire size was the cause. I felt it every time I accelerated from a stop until I got the flat fixed and installed the correct original wheel and tire. It was a very strange sensation.

12-20-2020, 01:45 PM	#1
Z28-TX Drives: 2015 Z-28 / '13 Howe TA2 Camaro Join Date: Jul 2014 Location: San Antonio, TX Posts: 43	Car pulls (unstable) under acceleration / deceleration (not on brakes) Just brought the Z-28 out of hibernation since COVID hit. New Goodyear F-1's just installed and new brake pads. After taking the car a burnish the brake pads run I noticed a weird sensation. The car feels like it's pulling (feels like from the real, yet not certain) under acceleration and deceleration. A good poke of the throttle or quick release of the throttle and I get this sensation. I would not feel confident on track ... it's that pronounced. This is a new one for me, what should I be looking at first? Thanks!

12-20-2020, 02:24 PM	#3
SIM GhostrdrZ Drives: ‘14 ZL1 M6 vert Join Date: Jul 2015 Location: Ohio Posts: 1,292 View My Garage	This is what the shock fittings look like. It’s a stretch but just a thought. Attached Images

12-20-2020, 04:11 PM	#5
SS Performance Drives: 02 Camaro B4C Join Date: Nov 2016 Location: Cape May County NJ Posts: 749	If it happens on both acceleration and deceleration I would suspect suspension/bushing issues. How many miles are on the car? Sometimes sitting for extended periods of time can cause bushings to deform. __________________ A man's garage is his castle 1969 Camaro SS 1970 Camaro SS 2002 Camaro B4C 2014 Camaro SS Dedicated Track Car 2015 Camaro 1SS 1LE 2008 HHR SS 1996 Silverado Crew Cab Long Bed Dual Rear Wheel

12-21-2020, 11:14 PM	#7
pzero Drives: 2015 Camaro Z/28 #968 Silver Ice M Join Date: May 2019 Location: Houston Posts: 366	Man hope you find the problem. Let us know and report back please. This sound stupid but check if rims are in right place. Front 19x11 and rear 19x11.5. If rear is on front it will rub on inner struts. Just check.... __________________ Current Cars: 2008 Honda CRV 2.0L 2015 Chevy Z/28 7.0L 2016 Chevy Tahoe 5.3L Past Cars: 1976 Chevy Malibu Classic 5.7L 1985 Chevy 2DR 4x4 Blazer 5.7L 1989 Chevy IROC-Z 5.7L 1995 Chevy 2DR 4x4 Tahoe 5.7L 2005 Chevy 4DR Tahoe 5.3L

12-20-2020, 02:21 PM	#2
SIM GhostrdrZ Drives: ‘14 ZL1 M6 vert Join Date: Jul 2015 Location: Ohio Posts: 1,292 View My Garage	When I run into issue(s) after work performed. I always backtrack; Check tire psi, check wheel lug nut torques, check for dragging brake pads( multiple ways and possible fluid flush/bleeding) Check for loose suspension or blown shock( the multimatics have little bronze bushings that act as “breathers”, check those are in place)

12-20-2020, 03:07 PM	#4
AustexaSS Build Date - Dec 08, 2014 Drives: 2015 Z/28, #1007, Black A/C Stereo Join Date: Oct 2015 Location: Austin, Texas Posts: 197	So prior to running the burnish procedure the perceived issue was not noticeable? Is the car pulling to one side constantly? You may have a collapsed brake line. i.e. if the car pulls left under braking the drivers side brake lines should be looked at. You may also need to look at rebuilding a caliper or multiple calipers as one could be sticking if the problem is constant regardless of weather you are applying pressure to the brake pedal. You could also do the brake burnish procedure again and see if this clears up the issue. If you have never flushed the brake fluid it is time to do so regardless. Jack the car up and check each wheel rotates freely and there are no signs or sounds of dragging between rotor and brake pad.

12-20-2020, 05:36 PM	#6
SIM GhostrdrZ Drives: ‘14 ZL1 M6 vert Join Date: Jul 2015 Location: Ohio Posts: 1,292 View My Garage	Either direction it takes you. Let us know what it is or give us all more details. Good luck

12-23-2020, 06:58 AM	#8
MIKZ28 Drives: 2019 Camaro ZL1 2004 Pontiac GTO Join Date: Feb 2018 Location: Roscoe, IL Posts: 136	I had this very same sensation when I had a right rear tire go flat and put on a spare tire from a 2010 Camaro SS. ( 20x9 ) The different tire size was the cause. I felt it every time I accelerated from a stop until I got the flat fixed and installed the correct original wheel and tire. It was a very strange sensation.