Vibration at highway speeds

[m235boy]

Noticed a vibration in the car around 75mph to 95 mph , feels like coming from the rear. Rearview mirror becomes blurry to the point you can't see out the back, feel it in center arm rest area and seat.

Wondering if it's wheels/tires or could it be driveshaft? I just had driveshaft rebuilt (new ujoint and new cv joint) immediately after I took the car car out from winter storage (sat for 6 months). Wondering if its maybe tire flat spotting and the driveshaft rebuild is just a coincidence.

Can driveshaft cause vibrations at those speeds if it was not balanced properly? I returned it to the shop that did the DS job and they will verify but don't feel like going down the rabbit hole to find this vibration when it's all along from the newly reinstalled DS. They are saying it's wheel related and will check balancing... Last fall (prior to winter storage) car was super smooth at highway speeds

[Johnr3524]

Seems like you're on the right path. Have the shop check the wheels. That much vibration with easily show up if it's a wheel.

Rule the wheels out and then have them focus on the DS.

[m235boy]

Originally Posted by Johnr3524

Seems like you're on the right path. Have the shop check the wheels. That much vibration with easily show up if it's a wheel.

Rule the wheels out and then have them focus on the DS.

Thanks, ya I will give them the benefit of the doubt. Just don't want to go on a wild goose chase replacing bunch of stuff and in the end still have the shake lol

These cars have a sensitivity that shows up more pronounced I guess. It is the 1st time I've had continental extreme sport contact tires (usually had michelin super sports) and never had tire flat spotting with the michelin's over winter storage.

[jvictormp]

If you don't have success with the wheels, be aware of my case. My car did some vibration at high speeds. Turned out to be the engine mounts. The right one was in awful condition. Left not that bad, but bad too.

[m235boy]

Originally Posted by jvictormp

If you don't have success with the wheels, be aware of my case. My car did some vibration at high speeds. Turned out to be the engine mounts. The right one was in awful condition. Left not that bad, but bad too.

Good point, I've thought about this. But unless the mounts wore down while the car was sitting in garage over the winter, I'm skeptical. The car was silky smooth last fall.

So far wheels check out, no bends in wheels so it's most likely driveshaft issue. Maybe it lost a balancing weight or issue with install

[CHE///MIST3]

Originally Posted by m235boy

Good point, I've thought about this. But unless the mounts wore down while the car was sitting in garage over the winter, I'm skeptical. The car was silky smooth last fall.

So far wheels check out, no bends in wheels so it's most likely driveshaft issue. Maybe it lost a balancing weight or issue with install

I am in the same boat....I had my driveshaft rebuilt by a well-known shop here in Texas and upon first test drive of installing this shaft I could hear a drone-ing sound starting at 64 mph. I had my shop take the shaft out, I went to the driveshaft shop and they re-built the CV and balanced it once more while I waited a couple hours. Had this reinstalled, but the drone sound remains, although somewhat less. Once I get up to about 90 mph, though the sound and feel is very pronounced and increases from there with speed.

I had the rear tires road force balanced, even found a slightly out of round wheel in the rear which I had repaired and re-balanced.
Also had the tie rods and arms replaced and the entire car aligned at the dealership.
Nothing has helped, the only thing I have not done is have the fronts balanced and rotated, but I highly doubt that is it.
Very frustrated, have spent well over $2,500 in labor and parts and wish I had just left my driveshaft alone. I wanted it rebuilt because of the "clink" sound that occurs in the 6spd models when you're at parking lot speeds and engaging gears.

I just cant understand how a balanced shaft, at what appears to be a very nice and high tech shop is still (allegedly) vibrating ?

Don't know what to do other than stay below 85 mph...

GM

[m235boy]

Originally Posted by CHE///MIST3

I am in the same boat....I had my driveshaft rebuilt by a well-known shop here in Texas and upon first test drive of installing this shaft I could hear a drone-ing sound starting at 64 mph. I had my shop take the shaft out, I went to the driveshaft shop and they re-built the CV and balanced it once more while I waited a couple hours. Had this reinstalled, but the drone sound remains, although somewhat less. Once I get up to about 90 mph, though the sound and feel is very pronounced and increases from there with speed.

I had the rear tires road force balanced, even found a slightly out of round wheel in the rear which I had repaired and re-balanced.
Also had the tie rods and arms replaced and the entire car aligned at the dealership.
Nothing has helped, the only thing I have not done is have the fronts balanced and rotated, but I highly doubt that is it.
Very frustrated, have spent well over $2,500 in labor and parts and wish I had just left my driveshaft alone. I wanted it rebuilt because of the "clink" sound that occurs in the 6spd models when you're at parking lot speeds and engaging gears.

I just cant understand how a balanced shaft, at what appears to be a very nice and high tech shop is still (allegedly) vibrating ?

Don't know what to do other than stay below 85 mph...

GM

same reason, I had the "clink" as well. Shop verified driveshaft and told me u joint and cv joint are toast. So off to get rebuilt and although the "clink" noise is gone, now have an M that doesn't like to go over 65 mph lol

Now that you mention it mine has a "drone-ing, humming sound" too coming from rear. It's going back to the ds shop to get it checked and re-balanced.

IF that doesn't work then new DS from bmw is in order?? Refund from shop for the rebuild and destroying of my original DS? Maybe get a mfactory carbon ds? All paths lead to more $$$ I take it.

[anerbe]

I had the clink noise when moving back and forth with no vibrations. Replaced center support bearing and greased up the center spline of the drive shaft. No more clink and still no vibration.

Perhaps the driveshafts are so sensitive, that any change/rebuild from factory can easily unbalance it. Maybe shops misdiagnose the slight slop in the joints as requiring a rebuild. Once they add material, weight balance the driveshafts, I believe this will probably unsettle further.

Just an idea, as I’ve done thru something similar, went conservative and no issues with noise/vibration.

[jvictormp]

I hope you find the solution, and if you do, please don't forget to tell us.

[m235boy]

Originally Posted by anerbe

I had the clink noise when moving back and forth with no vibrations. Replaced center support bearing and greased up the center spline of the drive shaft. No more clink and still no vibration.

Perhaps the driveshafts are so sensitive, that any change/rebuild from factory can easily unbalance it. Maybe shops misdiagnose the slight slop in the joints as requiring a rebuild. Once they add material, weight balance the driveshafts, I believe this will probably unsettle further.

Just an idea, as I’ve done thru something similar, went conservative and no issues with noise/vibration.

Yeah they are sensitive, just like if a wheel loses a small weight you'll get a vibration. I guess this is why driveshaft shops re-balance it after rebuilding.

So maybe a weight fell off the DS during install or the balancing washers/bolts on the diff/cv joint connection were not installed back properly. I'll update after everything is checked again.

[white_4door]

if it ends up being flat spots in the tires i recommend getting flat stopper ramps that you can get on amazon, i use them for storage in the winter and dont have issues anymore after they sit for a few months

[CHE///MIST3]

Originally Posted by m235boy

same reason, I had the "clink" as well. Shop verified driveshaft and told me u joint and cv joint are toast. So off to get rebuilt and although the "clink" noise is gone, now have an M that doesn't like to go over 65 mph lol

Now that you mention it mine has a "drone-ing, humming sound" too coming from rear. It's going back to the ds shop to get it checked and re-balanced.

IF that doesn't work then new DS from bmw is in order?? Refund from shop for the rebuild and destroying of my original DS? Maybe get a mfactory carbon ds? All paths lead to more $$$ I take it.

I think I fixed it. I posted of this issue on another thread and a forum member suggested me in this direction. Be sure to read to the end, it's a short thread.

https://www.m3post.com/forums/showthread.php?t=1231461

Of course ! The Germans WOULD make the differential and driveshaft to be balanced together instead of separate entities. Now you'll see in my photo below that my diff output shaft was marked with a white dot, which suggests no additional weights are to be added, BUT that was true during initial assembly back in 2009 with the driveshaft as it was first made. I had my current driveshaft rebuilt and sent back to me, but new parts were added and the entire unit balanced to itself only....once installed back on my car, whatever imperfections lay with my diff do not get cancelled out by the newly balanced driveshaft. Either that OR this drivehshaft company doesnt know how to balance, but they've been in service for 50 years and have excellent ratings, so....here's what I did:

Yep, I tacked on some small lead weights using medium thick cyanoacrylate adhesive ( aka, superglue) I started near the white dot and test drove, some vibration so I knocked off the weight then moved the weight 60 degrees, drove again, same, then finally 180 degrees from where I first started and that was it, the vibration is almost completely gone, I can just barely feel it, but I can't hear it anymore. It's not perfect, but even at triple digit speeds its almost unnoticeable. I will work on it a little more until it's perfect, but now I full control of this because the back of the diff shaft is just barely accessible under the car, thank you for the mercy, BMW. I'll keep playing around with mass and position. Currently I have 4.1 grams on just one location.

m235Boy, lets see what your shop has to say? In terms of historical knowledge, experience....then see if they are familiar with BMW's on-car balancing method. I have read here on the forums that some folks have swapped out the shafts with no issues, but I guess you and I weren't so lucky. Here is an easy, POTENTIAL, fix.....the correct way is using the weighed bolts or washers (for earlier models) which, is still nothing more than...adding weights, lol !

GM

[jvictormp]

Nice try, mate!

Don't know if you made any calculations, but if not, you were so lucky to choose the right magnitude of balance weight!

[m235boy]

CHE///MIST3 thank you for that info, it looks promising as to this being the issue for sure.

I'm curious as to how exactly bmw balanced the driveshaft and differential together at the factory.

[SAMM3Y]

Always start with wheels and tires, especially if you like doing hood rat shit in your car. If you spin the wheel around the bead it'll throw the balance off in the rears.

[m235boy]

Originally Posted by SAMM3Y

Always start with wheels and tires, especially if you like doing hood rat shit in your car. If you spin the wheel around the bead it'll throw the balance off in the rears.

Yup, in my case wheels and tires are balanced. Vibration/humming noise still there

[jvictormp]

Originally Posted by m235boy

I'm curious as to how exactly bmw balanced the driveshaft and differential together at the factory.

Yeah, me too!

[CHE///MIST3]

Originally Posted by jvictormp

Nice try, mate!

Don't know if you made any calculations, but if not, you were so lucky to choose the right magnitude of balance weight!

Ahh, sorry I kinda left that part out. So these are the washers BMW uses for the task: https://www.ecstuning.com/b-genuine-...r/26102284017/

Just estimating about how large they are I looked for a similar washer in my garage and weighed it on a gram scale..it was it 3.9 grams. So I started there. I think I’m going to purchase one of these and weigh it, but ultimately a fixed-weight washer is not the way to fix a problem 100% it’s not very customized to the task if you ask me....but it’s a start, or good enough.

GM

[CHE///MIST3]

Originally Posted by m235boy

CHE///MIST3 thank you for that info, it looks promising as to this being the issue for sure.

I'm curious as to how exactly bmw balanced the driveshaft and differential together at the factory.

I’m only guessing, but two ways would be to
1.) balance the driveshaft and the output pinion of the differential together on a lathe then mark the two parts and assemble on the car...or
2.) you could run up the entire assembly already installed in the car and use optical sensors to detect areas of outward inertia caused by imbalance....the old school way was to run up the assembly in the car with the rear wheels off and approach a piece of chalk to the shaft and wherever the chalk touched, go to the opposite side and add weight there ! BMW probably doesn’t use chalk though

Hopefully someone can chime in on this whole scenario...I too am just trying to understand.

GM

[SAMM3Y]

I changed the diff on my car and don't suffer any vibration issues so curious on whether balancing the diff is necessary.

[m235boy]

Originally Posted by SAMM3Y

I changed the diff on my car and don't suffer any vibration issues so curious on whether balancing the diff is necessary.

Curious as well, maybe you got a diff with a white dot indicating it doesn't need any special balancing washers or bolts?

[SAMM3Y]

Originally Posted by m235boy

Curious as well, maybe you got a diff with a white dot indicating it doesn't need any special balancing washers or bolts?

Dunno. It was a Diffs online rebuild through TMS. I slapped it on with original ds which is about ready to be replaced no vibrations at all.