Drive Shaft + Fly wheel = do both?

[BavarianZHP]

Hello!

I have this clunk in the rear end when I let off of the the gas pedal in gear (coasting/decelerating) at ~1500 rpm. It's much more pronounced in the lower gears (1 and 2) and can happen when engaging 1st or reverse. The car has had this ever since I've received it about 3 years ago and now it's time to get it fixed! Apparently, it's a drive shaft issue and I think the clutch fly wheel can be replaced too (nearing 90k). I've having a shop take care of the drive shaft... Should I just go ahead and have them also replace the clutch while they are there? Will this save me some labor or should I wait it out a bit longer? Sometimes I hear hear it "rattling" at idle - they tell me this is the flywheel.

Thanks all!

[Vas]

Clunking is usually from the rear diff mounts.

[BavarianZHP]

Yeah, I thought it was that too... and maybe even subframe tear (held my breath for that one) but all of the shops I took her too (Seattle's best indy's btw: Strictly BMW, Signature Independent, Eastside Bavarian) said the bushings and subframe were fine. I also took pics for the forum here and they appeared ok... Only Eastside Bavarian was able to narrow it down to the drive shaft after having the car for 4-5 hrs. They eventually found this out by putting her on the lift + driver reproducing clunk over and over for another mechanic to look for.

EDIT: Can't blame you for immediately going for the bushings. Eastside Bavarian thought it was the culprit at first too, until they looked at the car in-person.

[az3579]

The flywheel is an expensive part and is a big job to do from a labor perspective ($$). You really don't need to replace your clutch and/or flywheel unless it really is time. 90k is nothing for a clutch; I'm on 217k on the original clutch and flywheel, but I guess your driving style is a big factor in wear.

If your clutch isn't slipping and still feels good, don't bother doing the clutch and flywheel.

I'm not buying the driveshaft story. Logically it doesn't make any sense to me. What condition is the flex disc/guibo? What about the Center Support Bearing?

[BavarianZHP]

Clutch isn't slipping at all. I can floor it in high gear and everything's fine. Clutch travel is very good too. Maybe I'm being overly paranoid since it rattles when I'm at idle (maybe once every 3 months or even more? It's a rare occurrence really). It also sometimes rattles if I have the clutch engaged and I shut down the engine. Habitually, I have now been pressing in the clutch as I shut it down and this never occurs. This is my first manual, so I kind of panic sometimes whenever I hear "fly wheel rattle" from the mechanics.

Yes, guibo is fine too. That was the second thing we thought it could be. I did some research and instructed each shop to check 1) rear diff bushings (and all others as well), 2) guibo, and 3) subframe tear. None of them could find an issue except for Eastside Bavarian.. I'm not sure if they checked the CSB. Thank you for that and I'll look into it!

Here's what Eastside had to say as printed:

"When in 1st or 2nd gear around 1600-2000 rpm and decelerating, clunking noise in rear of the car. Please check and advise.

- Test drove in the rain and had a difficult time hearing the noise complained about.
- Inspected rear suspension and rear end components
- While driving out of the shop was able to recreate a noise from the rear which occurs during load reversal from drive to reverse.
- Inspected and found worn joint noise from the rear CV joint of the drive shaft

..."

They called me up and told me I would have to replace the entire drive shaft (I assumed they weren't trying to nickel and dime me) but I haven't done anything about it yet. They also said it isn't harming anything and just to keep an eye out if I didn't end up replacing/fixing it.

[az3579]

Clutch isn't slipping at all. I can floor it in high gear and everything's fine. Clutch travel is very good too. Maybe I'm being overly paranoid since it rattles when I'm at idle (maybe once every 3 months or even more? It's a rare occurrence really). It also sometimes rattles if I have the clutch engaged and I shut down the engine. Habitually, I have now been pressing in the clutch as I shut it down and this never occurs. This is my first manual, so I kind of panic sometimes whenever I hear "fly wheel rattle" from the mechanics.

A lot of E46 330's do this. Not sure about 325's, but I would consider this normal. Mine has done it since I've owned the car (going on 5 years) and have heard it on numerous other E46 330's. I wouldn't worry about it.

I have 217k on my clutch so I'm expecting one of these days, probably within a year or two, I'll have to replace it. At that time I will be replacing the flywheel, clutch, throwout bearing, and anything else I can get at "while in there". We'll see if new parts fixes the issue.

[Johnmadd]

A lot of E46 330's do this. Not sure about 325's, but I would consider this normal. Mine has done it since I've owned the car (going on 5 years) and have heard it on numerous other E46 330's. I wouldn't worry about it.

I have 217k on my clutch so I'm expecting one of these days, probably within a year or two, I'll have to replace it. At that time I will be replacing the flywheel, clutch, throwout bearing, and anything else I can get at "while in there". We'll see if new parts fixes the issue.

I changed flywheel clutch and throw out bearing and still have the same sound... it's fine/common.

[LivesNearCostco]

It could be the driveshaft CSB but if they were able to look at the driveshaft CV joint, it probably means they removed the exhaust and some of the heat shielding and would have looked at the CSB too.

Don't replace the clutch or flywheel at the same as driveshaft unless you have evidence it's bad. While a clutch flywheel job and driveshaft replacement both require removing exhaust, heat shielding, and CSB and disconnecting the driveshaft from the transmission, the flywheel/clutch job also requires removing the transmission from the car.

[danewilson77]

It's a clunk. Not a rattle, correct?

"No flamesuit required"

[BavarianZHP]

It's a clunk. Not a rattle, correct?

"No flamesuit required"

Yep. Definitely a clunk. It'll feel like the car lurches a bit when it happens (only when I'm decelerating/slowing and hitting ~1500 rpm)