S52 swap Clutch related metal noise...help needed

[Steeler325is]

1987 325is. Swapped in a fully rebuilt S52 last winter with a ZF 5 spd, JBR aluminum flywheel, sprung hub clutch and pressure plate kit that was sold together from BW. Installed backwards initially (rookie mistake, I know) although that is the direction it says on the clutch plate. Motor wouldn't turn over. Pulled trans back off and flipped clutch around the correct way and reinstalled. After about a 500 miles or so it developed a metal on metal noise coming from the trans/clutch area. This noise happens sometimes at idle, but mostly when I depress the clutch. Clutch worked fine, but I couldn't stand to drive it when it made a noise like that. A few days ago, I pulled the trans, PP, disk, and fly to see what I could make of the noise. A few teeth on the PP seemed to be bent slightly and the TOB had a good amount of wear for only about 1k miles. I replaced the PP, TOB, and clutch slave and pin. No visible signs of rubbing anywhere. Thought I had it solved with the PP replacement. Fired it up, sounded good and let it heat up. Started it again a half hour later and got the exact same noise as before. Obviously frustrated and looking for any advice from others that may have had this issue. At idle, it sounds like a sporatic clank on the bellhousing maybe clank clank. When I depress the clutch, it is more of a clankity clankity constant sound while it is held down. Not sure how I can attach the video I have of it, maybe a younger member can assist with that lol.

[bboylxix]

overall its pretty hard to diagnose noises over the internet, but i would double check your flywheel bolts and make sure they are torqued down. I've seen those back out especially with lightweight flywheels on S5x swaps.

Other than that, sounds more like a throw-out bearing issue since the noise is prevelant with the clutch pedal depressed (clutch disengaged). however, it seems like you have already replaced that component (doesn't always mean shit, could just be a crappy aftermarket bearing) other possibilities could be trans input shaft bearing or pilot bearing, although i couldn't imagine they would make a clank noise.

does the sound change while engaging the clutch under load/while driving?
or is it primarily a noise that occurs at either end of clutch pedal operation?

is there any way to know if this noise was occurring before? id assume not since its a swap you probably sourced parts from, but its valuable info.

[e30austin]

The LTW flywheel is not known for being the quietest thing in the world, for what it's worth.

[E30_pilot]

Its your flywheel. All light weight flywheels have "chatter".

[Steeler325is]

Noise occurs slightly in idle. Noise mostly occurs while engaging clutch, but also makes noise during driving under load (somewhat drowned out by the exhaust though) Pulled everything out again this weekend to replace clutch disk and guide sleeve. It looks like the clutch pivot arm has a lot of wear on it and when I tap on it, it sounds like a very similar sound. I have ordered a new arm now to see if that is the issue. Have now replaced the pressure plate, clutch disk, throw out bearing, slave cylinder, guide sleeve and pivot pin. Only thing left that moves in there is the pivot arm. so hoping that is the culprit. Thanks for the feedback!

[Sh3rpak!ng]

I'm going to assume the clutch fork retaining clip is new/intact/functioning?

FWIW the lightweight flywheel will cause a lot of chatter and noise. On acceleration, depending on the gear, you will get some rattling/grinding noise. This is the noise of the teeth of the gears in the gearbox buzzing back and forth against each other until you have sufficient load on them to hold them flat against the loaded face of the gears (hope this makes sense). The dual mass flywheel normally absorbs all of this chatter. Also as mentioned you will hear chattering on idle.

[Steeler325is]

Replaced the clutch fork retaining clip, the pivot fork, guide sleeve and put it all back together. Still same noise as before... I give up and will just drive it with the noise and just deal with the noise. It functions perfectly from what I can tell. Thanks for the advice gents!

[m3boost]

This happened to a car that was brought to me for transmission noise.. I thought it was the throw bearing as it had that familiar sound.. Instead, who ever did the last clutch install(which was done a while back) forgot to put in a pilot bearing.. Sometimes if you're not paying attention, the pilot most of the time will stay in place when the transmission is removed, but sometimes it will fall off or come out and stay in the transmission shaft.. Did you install a new pilot bearing? In the case of this car that I worked on, since it didn't have a pilot bearing, the shaft developed some play and that what was making the noise..just an fyi..