Pointers pls on a contemplated 2002 e46 m3 purchase

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The clunking is due to shifting speed and its from the drive shaft free play. Even after I refurbished it the clunking sound is still there but slightly lesser. 3 years later its loud again:)

As for the guibo, replaced mine earlier this year together with the long shaft mounting bearing. Basically, the failure is caused by the heat from the exhaust. When the Guibo fails, there will be a vibration. Just place your hand on the transmission tunnel and you can feel it.

The LSD on the e46m3 is derived from the e36evo, similarly the engine. The engine was bored slightly and compression was increased:)
 
ALBundy;788270 said:
The clunking is due to shifting speed and its from the drive shaft free play. Even after I refurbished it the clunking sound is still there but slightly lesser. 3 years later its loud again:)

As for the guibo, replaced mine earlier this year together with the long shaft mounting bearing. Basically, the failure is caused by the heat from the exhaust. When the Guibo fails, there will be a vibration. Just place your hand on the transmission tunnel and you can feel it.

The LSD on the e46m3 is derived from the e36evo, similarly the engine. The engine was bored slightly and compression was increased:)
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Looks like the both of you are talking about different clunking.
The clunking you are describing comes from worn driveshaft components ie, CSB or guibo.

The clunking issues due to the E46 M3's excessive 'diff lash' is well documented on many other forums as well as acknowledge by BMW themselves. Changing out all driveshaft components and rear subframe and diff mounts will not solve this clunking issue as it is a characteristic of the car. I will upload a video of my cars excessive diff 'play' when I have the time.
 
maxxsp;788285 said:
Looks like the both of you are talking about different clunking.
The clunking you are describing comes from worn driveshaft components ie, CSB or guibo.

The clunking issues due to the E46 M3's excessive 'diff lash' is well documented on many other forums as well as acknowledge by BMW themselves. Changing out all driveshaft components and rear subframe and diff mounts will not solve this clunking issue as it is a characteristic of the car. I will upload a video of my cars excessive diff 'play' when I have the time.
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Maxxsp,

Guibo doesn't cause any clunking. It just vibrates badly under acceleration, similarly with worn bushes especially those 3 on the differential cover. That was happened to mine when I first bought the car more than 3 years ago.

I even replaced the crown and pinion gears to the Motorsport version, with a 3.91 ratio. The clunking sound is omnipresent, unless when you ease off the throttle when up shifting and set the shifting speed to S1-S3.
 
ALBundy;788347 said:
Maxxsp,

Guibo doesn't cause any clunking. It just vibrates badly under acceleration, similarly with worn bushes especially those 3 on the differential cover. That was happened to mine when I first bought the car more than 3 years ago.

I even replaced the crown and pinion gears to the Motorsport version, with a 3.91 ratio. The clunking sound is omnipresent, unless when you ease off the throttle when up shifting and set the shifting speed to S1-S3.
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I replaced the 2 bushes on the diff cover 1 on the front of the diff and that cured most of my clunking. Under load the diff twists which is what causes the thump/clunk if the diff mounts are shot because the diff mounts have play in them. My car did/does not have any vibration issues.

This video highlights the clunking issue due to shot bushings.
[video=youtube;Zo4sU6gUWV0]http://www.youtube.com/watch?v=Zo4sU6gUWV0[/video]

Replacing the crown ring and pinion will do nothing because the play is in the LSD unit itself which BMW has stated IS an issue on the E46 M3. The clunking sound in my car is still present from 1st-2nd gear shifts at low speed as highlighted in the BMW Service Bulletin. Also, my car is a 6-speed manual, not SMG.

You say that it is driveshaft play that causes the clunking, yet after changing every part, the clunking is still present in your car. So wouldn't that point to an issue with the differential?

Here are some links to other forums highlighting the issue.
http://www.m3forum.net/m3forum/showthread.php?t=386037
http://www.m3forum.net/m3forum/showthread.php?t=42352
http://forums.bimmerforums.com/forum/showthread.php?t=1819944
 
Maxx,

1) If you have seen a dismantled LSD unit, there is no possibility the LSD unit will produce a clunking sound even at full lock up. There is only 2 pieces of clutch. The clunking sound is from the drive shaft head connecting to the flange. There is some free play and that's where the sound comes from. If one understands how a LSD works, then there is no possibility of any clunking noise emitting from the LSD. The only noise from the LSD is a grinding noise when the car is cold and during cornering. This happens to some M owners, and some got it sorted after replacing the LSD oil. The LSD only locks up when there is a difference of traction between the rear wheels. The clunking noise only happens when upshifting, on a straight line at moderate speed (which means the LSD is not locked up). That pretty much rules out the LSD as the culprit.

2) I changed the crown and pinion gears for two reasons, 1) more usable torque and 2) to check if the free play on the differential is normal. After replacing it and servicing the LSD unit, the amount of free play is similar. And hence I can deduced the sound is from the drive shaft head connecting to the differential flange. After I refurbished it, the clunking sound lessened as the amount of free play is reduced akin like a newer M3, but its still there as there is still some free play.

3) When the rear differential bushes are shot, there are 3 (including mounting bush), under acceleration there is a continuous low pitch grinding noise. The clunk only happens when up shifting, so there is nothing to do with the bushes. Similarly with the Guibo or long shaft mount center bearing.

Since both of you go to BM World, ask Taiko Wai :) He did some of the work I mentioned above, changing rear differential gears, refurbishing drive shafts, changing bushes and the valve adjustment (downloaded the specs for him, and he didnt even know the need to re-adjust the valves every 60000km), and he is quite well versed with the clunking issue, with me being his guinea pig 3 years ago!

To those that want to reduce the amount of clunking, get the drive shaft head refurbished:)

Cheers
 
ALBundy;788232 said:
SSmann,

Have seen this car running around a few times in PJ/Mont Kiara area.

Seems to be a nice car with very low mileage.

Few things, the oil leak is probably due to a pressure relief screw which is less than USD20. Mine was also leaking and once I got that replaced, it has been dry since then. If it leaks from the gasket it will be more "visible". You can either order this from local parts shop or get it from Turnermotorsport where I got mine.

As for the clunking sound when shifting gears, I would say this is pretty normal due to the SMG transmission and highly noticeable when the shifting speed is set to S5 or even S6 (only possible when DSC is off). I have refurbished my drive shaft head, but it didnt make the clunking sound any lesser so its normal.

As for engine ticking, again its normal as these engines doesnt run on hydralic lifters but pretty much on these shims. Someone I know has bought a set which is about USD400, and can probably share it with many of us. The adjustment is pretty much straight forward, but the engine will have to be cooled down overnight. Upon re-adjustment the ticking sound is reduced due to lesser free play. On the contrary, there is no increase in power but in fact some may experience lesser power or a "tighter" engine.

The tie rods and steering coupling are similar to E46 325 ones, and I got mine replaced recently.

All in all, this car is pretty "hardy" except the rear subframe mountings which I have seen one cracked before, but the owner drives the car way too hard. Mine is still fine despite some occasional drifts :)

Good luck and you will never regret owning the real deal!

Cheers
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Bundy, thanks for the post and reassurance on the car! Also thanks for sharing the quick fixes/remedies, much appreciated. And yes, after disposing my coverted 36 S50.....i cannot wait to get the real deal! After car, comes on track driving lesson!
 
BlackCat;788321 said:
So when are going to introduce her to us bro?
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Bro, been travelling just got back. Now sorting out paperwork. I hope to take posession by next week....then I will intro an "upskirt" teaser!!
 
Gents, thanks for all the discussion and various thoughts offered evidenced by literature and real life examples. This truly helps me understand various views, but more importantly that it is a common issue not unique to the car I am getting. Also good to know that there are mechanics who have tried and tested remedies with various E46 M3's, so mine does not have to be used for experiments!!! Hahahahahaha

Keep the active discussions going. Over time i shall introduce more topics for discussion and allow this thread to be a repository of some useful and valuable info for those who want a little education or contemplating a new purchase or facing problems with their rides!

And Leon, certainly i dont see this as any argument, more an educated discussion around the various causes and remedies for clunking. Well done!

RGds - S
 
Congrats bro! Wishing you many happy years with it!

p.s If anyone wants to know about clunking, I think a search on google will come up with results. There are different types of clunking and this discussion isnt really going anywhere. I think the "M-clunk" should not be dismissed. Yes it exists, and yes, there are other drivetrain issues as well. Whether BMW's SIB wants to be accepted or not, is up to the reader. I will post the SIB when I receive it. Even diffsonline.com has talked about the M-clunk. Link here

Also, I have spoken to Ah wai about the E46 differential because I wanted to buy it from him to install on my E36. FYI, he said it was the diff that causes the clunking and not to get it. He said it is very likely that it will develop a clunk even though it does not have it now. I won't take his word for it though. If he can say one thing to you, and say something else to me, then what is there to trust? While he is good at what he does, he does not know everything. There are plenty of things that were diagnosed by myself that he did not know. Not so sure if he's so well versed if he doesnt know that the valves need adjusting at that mileage. I have always taken what he says with a pinch of salt and will continue to do so.

If there is anything else to be said, lets start a new thread about this or move it to PM's. Lets not clutter ssmanns thread anymore and celebrate his new car with him!

Thanks for the discussion mate!
 
Akan datang.....jeng jeng jeng...tonite kenot sleep la....hehehehehe. Like losing my virginity la....hehehehehe

Am sure Bad has a comment on this la!!!
 
ssmann;789459 said:
Akan datang.....jeng jeng jeng...tonite kenot sleep la....hehehehehe. Like losing my virginity la....hehehehehe

Am sure Bad has a comment on this la!!!
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Hehe enjoy la bro... If cannot sleep, add some ghee and stroke it away.. Sure can tido and will smile summore. Congrats..
 

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