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Discussion Starter · #1 ·
I’ve been going in circles trying to figure out why I’m getting a driveline vibration on my 2002 325i wagon. The vibration appeared after I did some maintenance on the car and now can’t seem to figure out if something was installed incorrectly or if I’ve got a run of bad parts. Here’s what I’ve done:

1)replaced engine and transmission mounts with Corteco stock replacements due to cracking.
2)replaced cracked guibo with a new one. Verified that the arrows point towards the flanges, all six bolts installed from back to front of car as was original
3)replaced the driveshaft/csb with 2 new ones and one rebuilt one from Driveshaft Specialist in Texas. Not really any difference between the two new shafts, the rebuilt shaft was slightly better. They recommended replacing the shafts as they thought the issue sounded like a balance issue.
4)swapped to a different set of wheels and tires to eliminate them as an issue, no change.


The vibration is from the middle of the car and comes up at about 75-80+mph. Could it be a small alignment issue caused when I replaced the transmission mounts? Not really sure where to go from here, but I’m getting awfully good at dropping the exhaust off the bottom of the car!

Any help or advice would be appreciated. Thanks
 

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Discussion Starter · #3 ·
How do you know if the CSB is centered (to have the long drive shaft straight as possible)?
There didn’t seem to be much side-to-side play in the mount for the CSB, but that is something that I can check. I did preload the bearing towards the front of the car when installing.
 

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2016 340i xD 6-spd
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Maybe post pic of your guibo in place. If you're off by one bolt, you're off by a mile...and many get it wrong...and the directions to have the arrows towards the flanges never made sense to me, since both trans. and driveshaft seem to have flanges.

Anyway...it's easier to see than explain...and it would explain your vibration if it's off by one hole.
 

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Discussion Starter · #5 ·
Maybe post pic of your guibo in place. If you're off by one bolt, you're off by a mile...and many get it wrong...and the directions to have the arrows towards the flanges never made sense to me, since both trans. and driveshaft seem to have flanges.

Anyway...it's easier to see than explain...and it would explain your vibration if it's off by one hole.
I’ll get a photo when I drop the exhaust tomorrow, but I did double check the arrow directions, three going to the contact points on the transmission output flange and three going to the flange contact points for the driveshaft.
 

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2003 M3 6MT Slicktop
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23,390 Posts
what brand guibo are you using?

you use a torque wrench at all?
 

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Discussion Starter · #7 ·
what brand guibo are you using?

you use a torque wrench at all?
It’s a URO guibo. Trans/driveshaft bolts/nuts are torqued to 74 ft-lbs, csb to 16 ft-lbs and the E12 torx bolts at the differential are torqued to 62 lb-ft.
 

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OEM ///PLUS
2003 M3 6MT Slicktop
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URO ahh…well it depends where they sourced this from. If it has SGF embossed on it then it’s OEM. otherwise URO can be kinda hit and miss.
also have to ask, your wagon isn’t an XI is it?
 

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Discussion Starter · #9 ·
URO ahh…well it depends where they sourced this from. If it has SGF embossed on it then it’s OEM. otherwise URO can be kinda hit and miss.
also have to ask, your wagon isn’t an XI is it?
I admit that being URO the guibo, despite new, was a little suspect in my mind. I’ll check for the SGF logo. All the parts, aside from the driveshafts, either came from ECS tuning or FCP Euro. It’s a RWD wagon.
 

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2003 M3 6MT Slicktop
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well I’m not saying that “is” the issue. it could be. but not very common.
however i have seen vibration issues from people not torquing motor and trans mounts evenly.
 

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E30M3 Race F10 535 R1150Rt M Coupe
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Insofar as to the question of trans/engine alignment:

Slightly loosen all 4 nuts of the two trans and engine mounts. Take a LARGE prybar and jostle the engine and trans some. It should settle into the correct location.
Tighten all 4.
 

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Discussion Starter · #13 ·
There are ways to isolate the source of a driveline vibration before replacing parts. That is preferred to throwing parts at it.
Ok, I should clarify this better. There was NO vibration before changing out the flex disc, driveshaft and transmission mounts. As I stated in my original post, the guibo was 20 years old and cracked. While I was in there I swapped the transmission mounts and the driveshaft due to some play in the u-joints and preventative maintenance on the CSB. In hindsight I shouldn’t have messed with the driveshaft at all, but when you have to drop the exhaust, which the first time around consisted of having the original exhaust studs snap off at the manifold connection, necessitating their removal with an oxy-acetylene torch/hammer, it’s not something that I felt like doing again.
 

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Discussion Starter · #14 ·
Insofar as to the question of trans/engine alignment:

Slightly loosen all 4 nuts of the two trans and engine mounts. Take a LARGE prybar and jostle the engine and trans some. It should settle into the correct location.
Tighten all 4.
Thank you, will try that.
 

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E30M3 Race F10 535 R1150Rt M Coupe
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How do you know if the CSB is centered (to have the long drive shaft straight as possible)?
I think I get where you're going with this.
However given the rather small parameters of how the CSB slides over the two studs hanging off of the floor.....
Left/Right out of alignment parameters are almost nil.
One could I suppose...... severely twist and/or mount too far forward/aft?

But given that the bearing is mounted inside a rather large cupped piece of rubber: The bearing would more or less run straight and true.
The rubber cup, well that's another story.
 

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Discussion Starter · #16 ·
I think I get where you're going with this.
However given the rather small parameters of how the CSB slides over the two studs hanging off of the floor.....
Left/Right out of alignment parameters are almost nil.
One could I suppose...... severely twist and/or mount too far forward/aft?

But given that the bearing is mounted inside a rather large cupped piece of rubber: The bearing would more or less run straight and true.
The rubber cup, well that's another story.
That was my understanding as well. I paid attention to the twist of the CSB when preloading the bearing as well so as to keep it as straight as possible. Also, keep in mind that I’ve had three different driveshaft/csb combos installed and none has really changed the vibration significantly, so I don’t think anything with the csb installation is likely to have caused the issue.
 

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Discussion Starter · #17 ·
There is one thing about the CSB bearing that might have some effect that I thought of. When installing the csb/driveshaft combinations I didn’t install any butyl tape on the top of the csb between it and the body. The csb that I removed didn’t appear to have any on it so I didn’t install any on the new parts. Not sure that this would make a difference, but I figured it’s worth noting.
 

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E30M3 Race F10 535 R1150Rt M Coupe
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There is one thing about the CSB bearing that might have some effect that I thought of. When installing the csb/driveshaft combinations I didn’t install any butyl tape on the top of the csb between it and the body. The csb that I removed didn’t appear to have any on it so I didn’t install any on the new parts. Not sure that this would make a difference, but I figured it’s worth noting.
I have read countless (factory) repair instructions about installing the Butyl (Terrostat in the ETK) and guess what. About half of the cars that are supposed to have it......don't.
I haven't had an issues either way. If it has, we replace. Acts as an additional holder for the top.
 

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Discussion Starter · #19 ·
I have read countless (factory) repair instructions about installing the Butyl (Terrostat in the ETK) and guess what. About half of the cars that are supposed to have it......don't.
I haven't had an issues either way. If it has, we replace. Acts as an additional holder for the top.
That makes sense as I’m pretty sure that was the factory CSB on there that I removed and it didn’t have any.
 

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Discussion Starter · #20 ·
I had some time to work on the car again today and I took some photos. I still have the old driveshaft and despite having a pretty dry sounding CSB it hadn’t really been causing any issues when installed on the car so I decided to put it back on. It seems that solved the problem. I’m not sure why the replacement driveshafts were out of balance or if there was some other unseen difference, but any vibration in the driveline is now hardly noticeable and I’d say perfectly normal for a 20 year old car. Here are the photos of the installation before I put on the original driveshaft back on.

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932139


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