2001 m3 clunk noise help!

[BinBuilt]

So I replaced my guibo recently and did a shifter rebuild so I dropped part of the drive shaft and lowered the transmission and csb, and now when I put it in gear it’s when I press the clutch in only, the car makes this clunking noise, do you guys know what it could be? Mainly in 1st and reverse I hear it but that’s probably because I can’t hear it when I pic up speed? I just wanna know what it could be

[sapote]

So I replaced my guibo recently and did a shifter rebuild so I dropped part of the drive shaft and lowered the transmission and csb, and now when I put it in gear it’s when I press the clutch in only, the car makes this clunking noise, do you guys know what it could be? Mainly in 1st and reverse I hear it but that’s probably because I can’t hear it when I pic up speed? I just wanna know what it could be

slowly explain it in detail as i don't understand exactly at what point the clunk noise happened.

[BinBuilt]

slowly explain it in detail as i don't understand exactly at what point the clunk noise happened.

So I ended up wanting to replace my guibo and I did a shifter rebuild at the time too but I didn’t take the full exhaust off so I took the section 1 off and loosened the second section and I took the csb off, but I just bent the heat shield so I would have enough room to work with, i ended up lowering the transmission a little so I can get access to the clip on the selector Rod and after that I replaced my guibo and reassembled everything and now since then when I put the car in first gear and as I push in the clutch I hear this quick clunk and I wonder what it is.

[xansabi]

slowly explain it in detail as i don't understand exactly at what point the clunk noise happened.

I think I kinda know what he's saying, I (and most other E46's I've seen) have it too. Whenever I'm rolling slowly in 1st or R, and I press the clutch in, it's like this quick rattling/clunking sound. I've just gotten over it lol. Going to try a F8X driveshaft to see if that helps.

[sapote]

when I put the car in first gear and as I push in the clutch I hear this quick clunk and I wonder what it is..

You engaged (shifted to) 1st gear, then why need to push the clutch pedal down again? Or 'push in the clutch' means engage the clutch (to transfer the engine torque to the wheels)? was the car moving or stopped?

[hogger453]

I had a clunk once. Turned out to be loose wheel nuts. Left rear.

[BinBuilt]

You engaged (shifted to) 1st gear, then why need to push the clutch pedal down again? Or 'push in the clutch' means engage the clutch (to transfer the engine torque to the wheels)? was the car moving or stopped?

Yes I meant to say push in engage the clutch, it’s when I engage it it makes that clunk but it’s very brief

[sapote]

Yes I meant to say push in engage the clutch, it’s when I engage it it makes that clunk but it’s very brief

you don't push in to engage the clutch; you release the pedal to engage.

when clutch engaging and makes a clunk noise, means there is too much backlash in the shaft, from transmission output to the diff. To find which part, you need to lock up or hold the Guibo somehow, then rock the driveshaft aft of the CSB to feel any major plays, then continue to moving rearward to rock the next link of the driveshaft until reaching the diff. IOW, from the guibo to the diff the whole long shaft should have zero plays. The diff input to the 2 output shafts have some plays but they are not the root cause as you didn't touch them.

[ApexPothole]

I think I have a similar clunk in my car. My best guess is that the DMF needs to be replaced. I know that the PO did a clutch about a year before I bought the car and did not do a new flywheel, so I'm thinking its old and out of spec. This may be your issue, though this wouldn't explain why the problem is only presenting after doing a driveshaft job. Maybe there is something out of spec with your shifter rebuild and you are loading up a synchro when you shouldn't be?

[sapote]

I think I have a similar clunk in my car. My best guess is that the DMF needs to be replaced.

your case the clunk happened when the clutch is disenaged (pedal pressed down)? If it is, then it's different than OP's as his problem clunk when enaging the clutch.

The noise with clutch disengaged is due to too much rotational plays on the old DMF.

[ApexPothole]

I believe I get it in both situations, in addition to a lot of perceived 'lash' in the drivetrain when going off throttle in gear. There can definitely be a clunk with clutch disengaged and shifting between neutral to 1st, and IIRC the opposite also applies, though I've had the car off the road for the last couple months so I may be misremembering. From reading OPs initial post it sounds like he's saying its when he disengages the clutch as opposed to when he shifts while with the clutch disengaged (which is what I am experiencing) so not positive if its a similar situation.