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Odd Noise.....HELP!

So a couple weeks ago I had a buddy install the MGW shifter and things seemed smooth with the only problem being a shift (once) from 4th to 3rd making a "clunk" type noise.....we guessed it was the heat shield not being bent enough to clear the linkage.

When I had track day last weekend, the same noise happened once as I downshifted to 3rd from 4th but everything seemed fine as the day went on. No vibration, no rattle, no leaks and no codes.

Now today as I was driving the car as I got on it from 1st gear the same "clunk" noise took place, shifted to 2nd....same "clunk" noise. But the difference from the last time to this time is the noise is louder. Thought it may be something in my center consolel but it's now empty and still have the same noise. Again, no vibration/rattle, leaks or codes. Any ideas what it could be?

Plan to take it to the dealership next week and find the problem. No access to a lift so I can't look under it myself.


Any help or suggestions would be appreciated!!
 
Is it a metallic clunk? The reason I ask is that I get a plastic sounding clunk going 3-4 sometimes. It sounds like plastic pieces slapping against each other. Inspected everything thoroughly and can't find an explanation so I just live with it. It doesn't happen all the time just occasionally.
 
The center console echoes the noise but it sounds like heavy metal hitting plastic....if that makes any sense. As I stated before, it occurred the first time from 4th to 3rd and again at the track from 4th to 3rd but now it is done so in 1st gear under load/acceleration.

To be honest it almost sounds and feels like either the transmission is going to drop or the driveshaft is hitting the underside of the car. Just wish I could explain it better. When I drive the car smoothly, there is no issue.
 
SUPRMN said:
The center counsel echoes the noise but it sounds like heavy metal hitting plastic....if that makes any sense. As I stated before, it occurred the first time from 4th to 3rd and again at the track from 4th to 3rd but now it is done so in 1st gear under load/acceleration.

To be honest it almost sounds and feels like either the transmission is going to drop or the driveshaft is hitting the underside of the car. Just wish I could explain it better. When I drive the car smoothly, there is no issue.
Hmm not sure. The noise I hear is coming from the shifter/console.
 
I've talked to a couple people who know more about cars than I do and their thoughts and/or ideas are it could be the U-joint.

Anyone care to chime in on that possibility?
 
shipdriver said:
302 Hi Pro had a clutch clunk issue, which he elaborated on another Boss forum.
http://www.boss302forum.com/topic/15124-clutch-assembly-replacement-4000-miles/
I think I have this too and when I am back in the States, I'm having the dealer look at the pressure plate.

Thanks for the lead, however the sound I hear is more under acceleration after the clutch has been disengaged. I took to youtube and found a video clip of a loose U-joint.......sounds very close or similar to what I'm describing but much louder than the video shows. Just not 100% sure. Have an appointment this afternoon to it looked at. Will post findings when I get a chance. Below is the youtube link.

http://www.youtube.com/watch?v=8j8aNPamCQw
 
Today I found the problem and have to say luckily I did....however it came at a little extra cost. I will explain from the beginning.

Shortly after I bought the car I experienced some "grinding" in the transmission as I shifted from 5th to 6th gear. Knowing it wasn't my driving I took it in to have it looked at. The dealership found the syncros between 5th and 6th were messed up. Decision was to rebuild the transmission under warranty.

Fast forward to a couple months ago and I had an autocross day at one of the local airports. During one of my runs, a corner worker said they spotted something come out from under my car. They bring to me a bolt which looked "used" and not new. Their (SCCA) safety guy went and looked to make sure it didn't come from a sway bar or some suspension piece of the car and allowed me to continue running. Everything was fine.

Shortly after my autocross, I returned back to my home state (6 hours away) and brought the car (and bolt) to visit friend/family. While I was visiting, my brother and I along with a buddy who owns a shop put the car on the lift and looked over the car focusing on the front/rear. We did not see any bolts missing or anything from which it could have came from.

During my time home, I had the chance to put the car on a 1/4 mile drags strip and made approximately 10 passes with no issues. No signs of any trouble.

I drove the car home and continued normal driving as the months passed by. Several weeks ago now, I had the car lowered/new rims and tires, plus put the MGW shifter in with no problems other than clearance issues.

Last weekend, I had a mini track day in which I was able to run a 20-minute session and a 30-minute session. During this time, I only experienced one incident which made the noise I am describing above. This occurred as I tried to keep the RPM's up in an area of the track which shifting from 4th to 3rd would allow. When this happened so did the noise.

I completed the mini track day and because of the long day already and the heat, I passed on the drag strip the club offered as well as the track. No more issues from the car the rest of the time.

This now brings me to last night after flag football practice. I had a co-worker with me and decided I'd "show off" some and leave my "mark" in the parking lot. As I did, the same noise which happened on track day showed up but much louder and harder than before. It occurred immediately during acceleration and again as I shifted to 2nd gear. I drove the car home very gingerly and parked it.

Today I brought the car into the dealership and they jumped in the car with me. I was able to produce the same sounds I was hearing and before we even left the parking lot he told me to pull it into the shop. (This is where the "extra" cost comes in)

As I parked the car under the lift, I opened the driver side door and one of the feet from the lift was up. It hit the door, took a chip out of the paint and left a small dent!!! I was slightly sick to my stomach. Not sure I can get the shop to cover it since it was partially my fault but also theirs too.

So we put the car on the lift and the mechanic starts to look over the car. Needless to say after a few moments the problem was located! The "bolt" that came from my car which we thought didn't sure enough did. I was told the bracket which helps hold the Carrier Bearing (2 piece drive shaft) only had one of two bolts in it and this gave EXTRA movement to the drive shaft under acceleration. It would flex and bang itself under the car towards the center console!

The noise I was hearing was the bend in the drive shaft hitting the under carriage of the vehicle. Had I possibly done the drag strip I opted out of last week, the situation could have been a total disaster.

My mechanic has reason to believe (after he removed the other bolt) that when the transmission was rebuilt those bolts did not have lock tight on them or not tightened properly. Eventually throughout time and vibration one worked its way out.

Good thing about all of this is a new drive shaft was ordered and he is also replacing the mount which hold the transmission since it's been worn down from all the movement it's had. All placed under WARRANTY! Even if it wasn't put under warranty, he believes the dealership would cover the costs because it ultimately came from their work.

I'm just glad nothing broke as I was driving. Parts break and we all know that, but its never any fun when it happens to you. Sorry for the long write up but maybe it will help someone else in the future with a similar noise/problem.
 

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