loud clunk under acceleration

[atlas12b]

Hi i've got an 03 cobra with a brand new twin disc mcleod clutch. When I accelerate it clunks and is very loud. It pretty much goes away at higher speeds/higher gears. I've read about the infamous "cobra clunk" but I don't know for sure if that is my problem. It's very loud and you can hear it from outside of the car when I drive close to something like a car or a wall. To me it sounds like it's coming from the transmission. The clutch bites and works as it should. It doesn't clunk when I shift like I've read about the cobra clunk but is a constant clunking under acceleration or just keeping the same speed (again its very loud at low speed/low gears). When I let off the gas it goes away. Any help would be greatly appreciated. Also if someone pm's me I can text them the video of the clunking that I took today on my way home from work.

thanks

 

[Bigggy]

My guess is that a moving part is hitting something while under load, Drive-shaft, axle etc, you might check under the car what going on, but it def be hard to find the car sitting still.

 

[atlas12b]

I'm going to get underneath it this Friday and see what I can find. Hoping it's nothing serious :| Thanks for the advice.

 

[CobraBob]

Did the noise start after the clutch was installed? If so, did you do the install or a shop?

 

[atlas12b]

YA it started after the install and no a shop did the work. If it were the clutch though wouldn't you think the clutch would be feeling strange? The clutch is working fantastic. No slipping, the gears aren't grinding I mean the thing grabs very well. I've seen some videos on YouTube where guys had bad ujoints/
Driveshafts and they were making similar noises just not as loud and mine is just under load.

 

[MG0h3]

So this is a rhythmic clunk that speeds up/slows down with wheel speed or transmission speed?

If its just tied to wheel speed, Id look at the driveshaft, trans mount, something of that sort. I'm with you that Id expect a clutch feel problem if something from the install of the clutch went wrong.

 

[Bigggy]

So this is a rhythmic clunk that speeds up/slows down with wheel speed or transmission speed?

If its just tied to wheel speed, Id look at the driveshaft, trans mount, something of that sort. I'm with you that Id expect a clutch feel problem if something from the install of the clutch went wrong.

Thinking the same way and keep in mind, DS and a bunch of stuff need to come out when removing the trans.

 

[atlas12b]

So the rattle is coming from the clutch. I uploaded a video to youtube from last night. Here's the link
http://youtu.be/dUWyphSGNEU Also discovered that my inspection plate was missing :| And I tried adjusting the clutch a bunch of different ways. When the clutch fork was pulled "tighter" the noise seemed the get better but never would fully go away until the clutch was completely pushed in. When I adjusted the clutch 1. I realized I've never done it before 2. Seemed like my clutch cable was too short 3. I'm probably going to call around to some shops to get some estimates today because I just don't have the time right now to start this adventure.
Anyway, theres the video.

 

[atlas12b]

Oh and this was the original video from the inside of the car. From what I could tell at the time was that it only made the noise while under load but getting underneath it I discovered that the sound is always there just louder under load.

http://youtu.be/kyBN-4u0Je4

 

[Blueline]

It almost sounds like the input shaft is bouncing around a bit. I bet they damaged the input shaft bearing upon install. If it were my car I would drop everything and figure out what's wrong before you cause more damage. Good luck, that sucks

 

[MG0h3]

Not sure how long/mileage since the shop did the work but the first thing is to give them an opportunity to inspect it.

 

[Rich'sTRsvt]

My car made a similar sound when my TOB sleeve was broke off, although it did not make the sound all the time. Did you replace the sleeve with one of the tougher ones when you had the clutch done, or did they just leave the stock one in?

 

[Geno-04]

I had this problem once.....it sounded like rocks in a tin can. Had trans guy swear it was the trans. When I pulled everything down I crushed the pilot bearing when I was putting the trans back in. Changed the bearing and all was good.

 

[atlas12b]

It's being taken apart at a local shop. I talked to the dude a couple days ago. They said the throw out bearing was all messed up. Something about the install I think he said. I can't remember exactly I was busy at the time of the phone call. But I will post some pics and a better description after everything's done.

 

[Bdubbs]

Glad you got it figured out. I was going to guess maybe the flywheel. I had my stock flywheel rattle really bad, as the inner section was down to the rivets.

 

[atlas12b]

Well I just posted this to another thread I found under the transmission section. This is my terrible update.


So my problem sounds kinda similar to yours. These are my two videos...
https://www.youtube.com/watch?v=dUWyphSGNEU
https://www.youtube.com/watch?v=kyBN-4u0Je4

So the sound goes away when the clutch is pressed in and comes back when released. It is also way louder when under load (in gear, moving forward, foot on gas) and then "goes away" pretty much when you let off the gas.
I don't know. I took it to a shop recently they said the throw out bearing was all messed up. They also said the TOB retaining sleeve was not damaged. So they replaced the throwout bearing and the sound was still there so they took another look and now are saying the sound is coming from the inside of the transmission. So I'm in a pickle I really don't want to pay for a new transmission and I also don't think it's a header knocking into something.