vibration under acceleration - flex disc?
 

Folks,

Was towing the trailer yesterday, and working it hard merging onto the freeway, doing a solid flat-out pull through 2nd and 3rd gear. 2nd seemed to be a little rough, but the top end of 3rd had a *lot* of vibration.

Later on, I disconnected the trailer, and took her for a spin. The same issues persisted, with 3rd and 4th, in the upper ranges, being shaky enough that you didn't want to stay in the throttle. Definitely in the driveline. No vibration at low speeds, or at highway cruising speeds. If I downshift and bring up driveline rpm though at cruise speeds (3rd at 70mph) it definitely re-appears, regardless of being in the gas or just cruising.

So something is going on... And the only thing that comes to mind is a flex disc. All new front suspension, and new 4 wheel alignment. Car is smooth otherwise. And it came on rather quickly, I don't recall any vibration in the past month, and I fairly regularly accelerate at those speeds.

I do know that at high speeds, and high rpms (above 100+) it's always felt a little "trembly". Maybe with that amount of force on the flex disc, it's been slowly degrading over time, and now has reached the point where even in "routine" driving, it's apparent.

Thoughts?
Evan

I had this same problem. It took me two different shops, the later having a roadforce wheel balancer. They resoved my problem by finding two bent wheels that were not identified by the first"inexperienced" tire shop. Give this a check at a place with the premium wheel balancing machines. When the x is lifted up take a quick look at the flexdisc and look for tears, but it's prob not that. Good luck

Does the vibration exist at idle in gear also with foot on the brake?

No vibration at idle. None at acceleration in any gear below 4000rpm. Seems to be very evident at higher road speeds, under max acceleration, and was *very* pronounced with the trailer. Having the tires rebalanced tomorrow (and rotated), but, i'm 99.98% sure this isn't a tire or wheel problem. This is something moving in the drivetrain. Feels to me like either a bad mount, or a bad support bearing for a driveshaft (had that on the old volvo, and the sensation is similar to that). It's definitely related to the amount of torque being put on something under stress of acceleration. And it's not in off the line torque, as that would be evident in first gear, and second gear, and it's not noticable in first or second gear. 3rd, and 4th, (and probably 5th and 6th - if i wanted to get a ticket).

Is vibration in the steering or the whole car?
If it's the whole car it's either tires, drive shaft, or rear cv joints.
Front CV Joints and motor mounts will cause vibration at idle in gear with foot on the brake.

Iv had this problem for a while, iv posted on here and had quite a lot of feed back regarding the flex disc, I took a look but it looks new from looking at it from underneath, it drives me mad, I especailly get the vibration going uphill at a steady speed, its kind of a off and on vibration if that makes sense! Do x5's have just one flex disc? I'm not a mechanic so me checking myself was probably a waste of time though it did look in good condition but I didn't take the part off to inspect it properly! Would it need to be taken off to know if the flex disc was knackered? Cheers

it's the whole car, it's something driveline related. I'll get it figured out soon...and post the results. It'll drive me insane till I do.

sorry i read the title wrong, i think you get a vibration under the pedal and the floor pan area when its a worn flex disc, but thats just going by quite a lot of threads that i've read on it, let us know when sorted! good luck

Figured I'd update this. On friday, I took the car in and had the tires balanced and rotated. No change in symptoms, though I thought on the ride to the tire shop that the vibration seemed more obvious at highway speed, in any gear.

Stopped by the local shop I use, and talked with my mechanic. Odd symptoms, according to him, and he and I did some research online. Didn't come up with anything conclusive.

Just for the heck of it, I called my service advisor at BMW, knowing it might have to end up there. Described symptoms, and she looked up my vehicle, warranty expired that night, at midnight. She told me if I could get it in before 3p, have the shop foreman ride and verify the issue, they'd get it taken care of, though they couldn't look at the car until Monday.

It's at the dealer, awaiting further diagnosis. The shop foreman said that my vibration was quite odd, and that he'd not seen that before. So...I'm ecstatic this is covered under CPO, and very curious what they wind up finding.

I'll definitely update this thread when the problem gets resolved.

any update yet?

I'd say it might be the center bearing of the rear driveshaft... That can cause the symptoms described and is often overlooked.

hmm i'll mention it to the mechanic, cant seem to find that centre bearing on realoem, is there just one flex disc on these x5's? cheers

One for the front, one for the rear. The rear would be the one to give problems, but not a common problem at all. A worn flex disc (also called guibo joint) usually causes harsher feel in shifts, but as I said, not common on E53's. The center support bearing on the other hand can cause what you described.

They're both on this page in realoem.

RealOEM.com * BMW E53 X5 4.4i Drive shaft, single components, 4-wheel

cool thanks for that, appreciate it, i can see the flex disc in the diagram but struggling to see the centre support bearing, which number on the diagram is it? thanks

#8

Okay, after much a lot of investigation by the dealer...they are proposing a few things.
one, they say my rear suspension bushings are shot. They suspect the left drive axle is also slipping, but are unable to determine. For now, they recommend replacing the lower control arm bushings and the lateral links, and then getting it aligned. Then, see if that fixes the vibration. If not, we move onto the drive axle, and transmission and transfer case.

They want a rather egregious amount of money for suspension work, so I'm going to go talk to them tomorrow. I would prefer to buy parts, and have them install them (I presume that if the vehicle leaves their property my warranty will be expired, because warranty technically expired last friday). That's understandable. Instead of just doing the couple bushings they recommend though, I'd rebuild the entire rear suspension. Everything rubber will get replaced.

So...that list becomes... upper and lower control arms, two ball joints, two lateral links, two guide links, two front differential bushings, one rear differential bushing. So...if possible, I'll get them all of those parts by Monday, and then see where things go.

I have their loaner car, which is a nice Z4, but I *really* miss my X5. I simply adore that thing.

I'll keep this thread updated as progress continues.

thanks for help weasel, i'll speak to my mechanic about and see what happens! cheers

Okay. Update on this issue.

Replaced rear suspension this week.
RealOEM.com * BMW E53 X5 4.4i REAR AXLE SUPPORT/WHEEL SUSPENSION

This included both lower control arms, ball joints, integral links, upper control arms ( 06, 11) in the diagram.

Ordered aftermarket axle to replace right rear - didn't like it at all - housing was thicker, only 4 threads going into diff case instead of 8 threads like the bmw axle, and the flange on the differential side was different. Decided to order OEM axle and use that. OEM axle has not arrived.

Thusly - with all new rubber, the vibration is still present. No change.

Next week it gets the new axle (soon as it arrives). Then at the end of the month it gets new subframe bushings. I really think this is either axle or transfer case. We'll figure it out, but I think it's axle. It's coming from the rear, but only when under load - either acceleration or deceleration. I'll keep this thread updated...

any update yet?

After replacing the entire rear suspension, the rear driveshaft, tires, and a bunch of other stuff, I found a mechanic who actually diagnosed this problem, and it turns out it's the rear differential. The carrier bearings in the differential are bad.

A good mechanic can be priceless...

My vibration is during acceleration. At stop in neutral, i can rev up the engine and no vibration alt all. Though it might of been the engine mounts. I had everything replaced in the front end, control arms, axles, the works last year. Only thing i can think of is the Flex disc. However, when on the highway and the cruise on no vibrations, only when i accelerate. Any ideas?

I never got the vibration on motorways , it was mainly around town and under load or going uphill, it happened when going up hill at a steady spees..

What happen? Gotta know this.. I have similar issue..

Would this be the same for the front end drive train assembly? If the vibration is coming through the front end?

NSCUCARJOCK,

Was it the carrier bearings?

Was this ever Resolved?

Your hidden omen most likely is a separated drivers side motor mount.

I never truly resolved my issue. Rear mounts need to be looked at. Also, what have you done to your vehicle. My flex disc did not solve the issue. I sold my vehicle but I always wondered if the rear axle cups were pitted inside. This is a known issue with my other car upon acceleration. If it's all the time that is. If it's at higher speeds I would guess the wheels or bushings