Loud thump when hitting brake in reverse

ceasefire · 2024-06-20 00:33:31

Backing my 04 crossfire (85K) down he driveway if I hit the brake there is a loud thump that you can even feel in the front end (I believe). I watched the front with the hood open and found the suspension crossbar bounce about an inch along with the noise. I replaced the crossbar bushings but that didn't solve the problem. The car is a 6 speed. My local car repair installed the bushings for less than $200 (from Needs Wings) and told me that there were additional problems but would not tell me what they were until I paid the $200 diagnostic fee. I though I had it figured out and spent the same amount having the bushings installed. Anybody have any ideas (suspension links, motor mounts, etc). The car has only 85K on it. Thanks for any advice or help. I'm not paying the local shop $200 to tell me what they know.

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Jun 19, 2024 | 08:33 PM

#1 (permalink)

ceasefire

Thread Starter

Joined: Mar 2011

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Loud thump when hitting brake in reverse

Spoiler

Jun 20, 2024 | 02:36 AM

#2 (permalink)

M60A3Driver

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Joined: May 2023

Posts: 3,180

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From: New Jersey

Re: Loud thump when hitting brake in reverse

Quote:

Originally Posted by ceasefire

Spoiler

It could be your flex discs or engine mounts.
Check your flex discs: With the car off reach under and rotate the drive shaft and see if you hear that clunking noise. Also check them for cracks or tears.

Check engine mounts: If you have help, have someone video your engine. (Don't let the person videoing stand in front of the car in case your foot slips off the brake pedal).
Press your foot on the brake and hold it there. Put the car in drive. With your other foot rev the engine a little bit. Now do the same with the car in reverse. Watch the video and see if the engine moves a lot.
You can also check it with the engine off. The second video shows how near the end of it.
Here are links to a couple of videos:

Jun 22, 2024 | 02:36 PM

#3 (permalink)

ceasefire

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Joined: Mar 2011

Posts: 18

Likes: 2

Re: Loud thump when hitting brake in reverse

Replaced the flex disc with the unit from Needs Wings a couple thousand miles ago. I'm suspecting engine mounts. Suspension links?

Jun 22, 2024 | 08:58 PM

#4 (permalink)

GraphiteGhost

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Joined: Jul 2009

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From: Central South Carolina

Re: Loud thump when hitting brake in reverse

Quote:

Originally Posted by ceasefire

Replaced the flex disc with the unit from Needs Wings a couple thousand miles ago. I'm suspecting engine mounts. Suspension links?

Might be time to set the front end up on jackstands and check the entire front end suspension. Have you recently done a front brake job? Any service to parts forward of the rear of the front wheels besides what you did before the sound was first noticed? After checking the front end for any play, come back with an update. Also, while the car is up on the jackstands, take a look at the flexdisk job to see if anything came loose. Good luck!