Thump during braking occurs at 10mph

I have an 04 pontiac grand am, and when I come to a slow stop whether or not I am braking, it thumps somewhere from infront of the firewall. This sound is more noticible in neutral and with slight brake pedal pressure.

It sounds like it is transmission, but it is hard to tell, I dont notice any change in rpm's when this happens, so I really doubt it is the torque converter lock. Could it be a loose strut on the dirvers side? I am just shooting for ideas.

So no ideas?:licka:

It may be a loose brake caliper that you only hear when you are going slow. The other thing to check would be the motor mounts. It is possible that one is bad and allowing movement when you come to a stop.

Ok, that would be a good place to start, the car has less than thirty thousand miles on it, but I wondered about a loose strut?

They are a possibility especially since the grand am has issues with knocking due to upper strut mounts. Bounce the car and see if you hear the knock. Had a grand am and the struts made a noise the entire time we hand it.

After test driving for about half an hour, I noticed that the car was not making the noise in drive, always occurs at about 10mph when I am slowing down, regardless of whether I am braking or not. It sounds like something is disengaging......there is not so much a thump, it is more like a metalic sound. Hard to explain. At the same time that this occurs there is a noticable reduction in speed like the transmission downshifted, but it is neutral.......I am confused, any pointers, this eliminated struts, and I think brakes, unless they engage at speeds less than 10mph?

Take the car to a tranny shop and have them diagnose the problem. It sounds like you may have a cracked flywheel. If so it will need to be replaced. Not cheap by any means but they should be able to tell you if the tranny is the issue.

whats up with these!

I had the exact same problem however it only occured when i was coming to a stop in neutral, it happened right before i stopped, bang, right from the front end, it wouldnt happen if im moving slowly then stopped but only when coming to a stop when traveling as you said 10mph or higher

however if your's is doing it while both in D or in N its much more serious issue, your not suppose to pop it in N and come to a stop with an auto, hard on it, so I just never did it and never had the problem, i just noticed it once when i did pop it in N for whatever reason, bang, few more times to make sure, bang, never did it again

recently had my trans rebuilt, decided to test it out just in case, well guess what, no more bang

maybe its not your trans but thats my reply