[850CSi]

Additional data point, from a 200 mile trip I made yesterday...

There is roughness felt throughout the cabin (and I can feel very easily in the seat and gearshift but not as much in the steering) when cruising at highway speeds under any sort of load. It instantly disappears when coasting. More noticeable at 80 than 60 but same sensation of roughness with any sort of power being applied.

I think it's pretty clear the culprit(s) have to be somewhere between the transmission and wheel bearings, but what?


(Car feels very smooth at lower speeds and less aggressive rates of acceleration, engine is very smooth at idle)

I did notice when I changed my transmission fluid that it had gotten low over the years. But I'm assuming I'd be seeing a lot more trouble if I was dealing with a transmission going bad?

[E92William]

I think a vibration like this coming from the transmission itself is very unlikely without some sort of transmission problem. This is getting narrowed down I think to driveshaft center support bearing, suspension or tires.

I did notice when my front arms were that bad that it did kind of exactly that, I guess since they were collapsed they would make the subframe be almost touching the metal on the arm and when I would accelerate the front would lift up and take up that play and remove that road vibration.

Also for some insight I put a couple new Indy 500s in the front and that has almost completely eliminated my steering wheel visible vibration and seat and floor vibration, the car is still out of alignment so should be better after aligning in a few days.


This was my CSB which honestly did nothing when I replaced it so I would check and if it's the same as this just skip it and check the suspension out

[850CSi]

Thanks man.

I'm a little skeptical about the cause being suspension-based, especially anywhere up front, because I feel it in the seat, and it only happens under load. There's a clear relationship been my gas pedal and the roughness. Everything feels fine when I'm coasting.

That being said I suppose aggressive acceleration/constant torque load puts more stress on suspension components (or perhaps subframe bushings?) than just coasting along?

For what it's worth I did notice that my rear strut boots are torn and they're sort of rusty.

[E92William]

I thought that hard acceleration and loading up of the drivetrain was mostly straining the driveshaft, suspension makes perfect sense too specially the rear. Have you tried prying around the rear suspension maybe differential mounts and such? I asked my alignment guy about vibrations in the car he said that vibration in the seat was the rear of the car and steering wheel is front.

[850CSi]

An update.

Was on the highway yesterday and noted that the high frequency vibration I was getting was identical cruising at 75mph whether I was in 3rd gear at like 5k rpm or 6th gear at like 2500.

I’m still a beginner DIY mechanic but everything I've experienced pointed to an issue somewhere between the flex disc and rear wheels as far as I could tell. All along the driveshaft has been my prime suspect.

So... got under the car today and seems like this might be my problem (or at least part of it):

[Brian86]

Yes sir. Torn carrier bearing webbing can certainly cause driveline vibration

You should have noticed that when you didn't he clutch :P

It's a pain to change. I got lucky and found low low mile complete driveshaft assembly in a salvage yard.

[850CSi]

Originally Posted by Brian86

Yes sir. Torn carrier bearing webbing can certainly cause driveline vibration

You should have noticed that when you didn't he clutch :P

It's a pain to change. I got lucky and found low low mile complete driveshaft assembly in a salvage yard.

Yeah, I was kicking myself -- I absolutely should've taken a closer look at the driveshaft and CSB when I had it out.

Though in case it benefits anyone in the future... it took me like 20 minutes to expose the CSB and get that picture. It can be done without removing the exhaust.

My plan is actually to source a rebuilt driveshaft. I've read that these torn center supports can be caused by failing u-joints. And as you say, it's not an easy job to replace the CSB so I'm just going to replace the whole thing and hope that solves it.

[E92William]

I replaced the csb and trans output shaft guibo at a pay to rent a lift place and honestly I spent enough time there to cover a new or rebuilt and balanced driveshaft lol so I would go that way if you can. That center bearing people on YouTube make it seem easy to remove but I had to use the shops 20 ton press and bearing puller tool to get it off. But yours is definitely ruined

[chriszach1]

I just replaced my entire suspension and some support pieces. My 06 325i has about the same amount of miles. When I was swapping out the lower and upper control arms, I was shocked at what they put on those cars. It may not be a bad idea to give your suspension a refresh. Here are a few pics.

[850CSi]

Yeah suspension refresh is definitely my next step. Just debating what to go with and how far to take it.

Ordered the new driveshaft today, should hopefully have the car going again this week. Excited to see if I’ve finally resolved my car’s mechanical issues.

[chriszach1]

Originally Posted by 850CSi

Yeah suspension refresh is definitely my next step. Just debating what to go with and how far to take it.

Ordered the new driveshaft today, should hopefully have the car going again this week. Excited to see if I’ve finally resolved my car’s mechanical issues.

I got a really good deal on an ST XA suspension. The other parts I got from FCPEURO. Here is the link:

https://www.fcpeuro.com/products/bmw...e93-bmwmcaktfr

I also replaced both sway bar links.

I'm building mine for track use, so that's why I went with these parts.

[850CSi]

I’m definitely tempted to do the m3 control arms.

Mine is the opposite of a track car, though. Have been repeatedly debating B12 pro kit vs just sticking with my non-sport springs and replacing struts with b4. The car is my winter driver & family vehicle. I basically want it to feel like a grand tourer to the extent possible — high speed stability and compliance on bad surfaces. (I have a 987 for shenanigans.)

[850CSi]

MY CAR IS FINALLY FIXED

I wound up calling Driveshaft Specialist of Texas based on a lot of positive reviews I've seen here and elsewhere. Unfortunately, they are no longer selling rebuilt driveshafts for our cars. There are two options:
--Send yours in and have it rebuilt with OE style staked U-joints ($400 including shipping both ways)
--Buy a new & totally aftermarket model that is designed to be a correct fit and is made with replaceable (and, crucially, non-greased) U-joints (if I recall correctly I believe he said they're 1210 series) ($525)

After agonizing over it, I wound up going with the new & rebuildable style. I think the fact that I plan to keep the car for a long time factored into my decision. I'll post a photo of my old & new one side-by-side below.

When I removed my old driveshaft, in addition to the tear in the center support bearing, I noticed that my rear u-joint (which meets with the diff flange on my car) wasn't moving totally freely. It's not that surprising because it's somewhat exposed to the road below. This may be a quirk of this particular model because I think a lot of other E90s have a different setup (CV joint? a second flex disc?) at the diff.

I definitely should've taken a closer look at the driveshaft when I had it out for the flywheel job (only 1k miles ago), but you live & learn.



...Put the new shaft in, buttoned everything back up, fired it up, took it for a spin. Floored it. Made a 60-mile highway trip. Holy crap! Drivetrain is silky smooth again! Car hasn't felt like this in years.



A few quick notes about the job:
--I cannot emphasize enough that, with any job on these cars that involves the exhaust, the very first thing you should do is check the condition of the studs/nuts on the downpipe/primary cat connecting flange up front. If there is any rust at all, take it to an exhaust shop and save yourself a lot of aggravation by paying them $75 to torch out the studs and put in new bolts/washers/nuts. I spent like 6 hours messing around and then ultimately cutting them off when I did my flywheel. It took me like 20 minutes to have my exhaust lowered this time. (You could just leave it hanging by the exhaust manifold and that might give you enough clearance but I think that's a bad idea)
--Be sure to order new locking nuts for the guibo (and go ahead and replace the guibo if you haven't done it yet). (TIS also calls for replacing the other ZNS hardware, including the flex disc bolts, and I think it's wise to follow that advice)
--Check the condition of your transmission output centering sleeve as well as the diff flange. I neglected to do this.
--Good time to refresh your shifter/bushings/etc if you have any inclination (I actually wound up removing my SSK and going back to stock).

[850CSi]

Anyways...

18 months ago my car was falling apart. 170k miles, 15 years, and yes some neglect. It spent a good chunk of its life parked on the street in densely populated areas in the rust belt with bad roads. It was leaking oil everywhere and it drove like absolute shit. And I had never really done any serious wrenching. I pretty much parked it for over a year.


A ton of DIY work later... I've learned a lot and I'm now a suspension refresh and 330i tune away from something special. I am brought back to how it felt 15 years ago when it was brand new. And I would drive it across the country in a heartbeat. (Though perhaps with some water pump anxiety)

[2one3E90]

How tf does the Duel mass flywheel have a hole or get that messed up?

[850CSi]

Originally Posted by 2one3E90

How tf does the Duel mass flywheel have a hole or get that messed up?

I can’t say for sure but my guess is some structure that interacts with the springs wears out (or the springs themselves wear unevenly) and that causes something to fly loose with some force?

Either way, I’m not the only person on here to experience an exploded flywheel and gunk all over the bell housing.

Actually getting ready to do the same job on my 987 (apparent failing DMF at only 100k miles). I’ll be curious to see what that one looks like.

[E92William]

Glad you got it sorted out! This stuff often seems to take a long time and money to figure what it is. This makes me rethink if the bit of vibration I still have that's sometimes intermittent between 80-100 could be this. I did not have a proper closer look at the driveshaft u joints when I had it out.. this design with the staked units is just horrible by BMW

[lowrydr310]

Originally Posted by E92William

this design with the staked units is just horrible by BMW

I'm actually very glad to know that this company is offering an improved aftermarket option, and the price isn't bad! My 325i needs a new center support bearing and is missing the plastic damper ring so I get a 'clink' sound when loading for unloading the driveline. I may just buy a new shaft instead of wrestling with the bearing, and with 250K miles on the original u-joints it wouldn't hurt.

OP, glad you got it all sorted out. We're you feeling a constant vibration or just when accelerating? I have been following this thread chasing my own vibration issues on my 330 but mine are constant and after replacing two bent rims it improved significantly, but I'm focusing on tires now.

[E92William]

Dude honestly with how much time and money in parts it takes to do a csb and guibo I would buy the brand new driveshaft too. They're missing out on a huge market by not actively advertising this on the forums

[Brian86]

WooHoo!

These are simply brilliant cars. Even better after some blood and sweat bringing one back from the brink.

Mine is 90% there. Going to do a prophylactic water pump/cooling system refresh when the weather warms up and give the paint some love and I'll be in 'maintain' mode.

I'm still suffering some very minor driveline vibrations in my 4wd. Minor enough that I don't need to fix them and won't be throwing parts at it, as there aren't many parts left to replace.

Basically an intermittent minor driveline vibration at highway speeds. Comes and goes. I wonder if there isn't something going on between the snow tire tread slip, lash in the front diff, and degree of clamp in the transfer case clutch which makes it come and go. Or if perhaps it's just the snow tires/wheels. The salvage yard OE wheels aren't as round as they should be. I'll know more when I'm back on the summer tires.

My darned rear view mirror also resonates with the motor at about 2300-2500rpm. The motor is butter smooth but somehow it's working it's way up to that mirror.

[850CSi]

Originally Posted by E92William

Glad you got it sorted out! This stuff often seems to take a long time and money to figure what it is. This makes me rethink if the bit of vibration I still have that's sometimes intermittent between 80-100 could be this. I did not have a proper closer look at the driveshaft u joints when I had it out.. this design with the staked units is just horrible by BMW

Thanks!
First thing I'd try to figure out if I was in your shoes is whether it's strictly load dependent or if there are other variables that affect it.

Originally Posted by lowrydr310

I'm actually very glad to know that this company is offering an improved aftermarket option, and the price isn't bad! My 325i needs a new center support bearing and is missing the plastic damper ring so I get a 'clink' sound when loading for unloading the driveline. I may just buy a new shaft instead of wrestling with the bearing, and with 250K miles on the original u-joints it wouldn't hurt.

OP, glad you got it all sorted out. We're you feeling a constant vibration or just when accelerating? I have been following this thread chasing my own vibration issues on my 330 but mine are constant and after replacing two bent rims it improved significantly, but I'm focusing on tires now.

I agree with E92William that anytime you're looking at swapping the CSB you may as well just do the entire driveshaft (whether new or getting your OE one rebuilt). It's more $ but less work and you ideally rule out other causes for a long time moving forward.

As documented in my posts here I had different symptoms at different stages. When my car was at its worst point (before I did any work on it), I had a lumpy idle (felt a little like a misfire) combined with general roughness and heavy vibration under moderate-to-heavy load, especially once I got up to 3000-5000rpm.

Engine mounts helped but didn't make a huge difference. Flywheel and clutch job definitely made a major difference (and my idle got super smooth after that + plugs/coils/CCV) but I still had persistent vibration under anything approaching heavy load, and in particular when accelerating aggressively in 1st and 2nd gear. That led me to suspect the driveshaft, especially with the symptoms I had at highway speeds -- constant buzzing under any load, which was identical regardless of gear selection/RPM, and immediately disappeared when coasting.

I did do a ton of work, but at the same time literally none of it was just throwing parts at the car and hoping. It all had to be done regardless. That's why I was thrilled when I found my center bearing was torn -- it gave me the justification to throw another expensive part at the car.

One thing I'd caution against is folks taking TOO much away from my particular symptoms and experience. I say that because E9xs have a few different driveshaft setups depending on your particular engine/transmission/differential/bodystyle combination. For example, realoem says your 330i doesn't have a second u-joint at its rear like mine does. Instead, I think it has a rear guibo?

The Bentley manual for our cars has a lot of helpful info and suggestions about possible sources of vibration depending on particular observations. I just noticed there's even a chart in there.

Originally Posted by Brian86

WooHoo!

These are simply brilliant cars. Even better after some blood and sweat bringing one back from the brink.

Mine is 90% there. Going to do a prophylactic water pump/cooling system refresh when the weather warms up and give the paint some love and I'll be in 'maintain' mode.

I'm still suffering some very minor driveline vibrations in my 4wd. Minor enough that I don't need to fix them and won't be throwing parts at it, as there aren't many parts left to replace.

Basically an intermittent minor driveline vibration at highway speeds. Comes and goes. I wonder if there isn't something going on between the snow tire tread slip, lash in the front diff, and degree of clamp in the transfer case clutch which makes it come and go. Or if perhaps it's just the snow tires/wheels. The salvage yard OE wheels aren't as round as they should be. I'll know more when I'm back on the summer tires.

My darned rear view mirror also resonates with the motor at about 2300-2500rpm. The motor is butter smooth but somehow it's working it's way up to that mirror.

Thanks, I'm thrilled. I agree these are special cars, and the thing that makes me feel better about putting all of this work into it is that I'm hoping it should be pretty reliable for a long time to come.

FWIW what you're describing with your car reminds me a bit of what we experienced when one of the front cv axles went south on my wife's (now gone) E61. I think that's not an uncommon problem on the xdrive models. Might be worth getting under it and seeing if there's any play in either of them. But yeah could be a number of other things also.

[850CSi]

Just so other folks might benefit from my research as far as driveshaft options.

As I mentioned before, Driveshaft Specialist of Texas comes highly recommended on a number of BMW forums, and they had two options, at least for my particular model: OE-style rebuild or a new one with replaceable u-joints. Both guys I spoke to there didn't really push me in either direction. I think there are advantages to both approaches.

I also spoke with another shop, Driveline Service of Portland (driveshafts.com). I got the impression that they're selling the same new driveshaft that I purchased from Driveshaft Specialist, for the same price.

There's also another site, wholesaleimportparts, that was selling a new aftermarket driveshaft at $495. I wouldn't be too surprised if it's also the same one that I ended up with, because it looks pretty similar in the photos.

Finally, I believe Beyer Motor Works in Chandler, AZ rebuilds driveshafts for our cars and during the process swaps the staked u-joints for replaceable ones. I got the sense that they do good work. The catch is that they don't sell directly to the public. I believe Turner/ECS and perhaps Bimmerworld sell them, though, and they tend to run closer to $800+.