Inconsistent Vibration at 90-130kph
 

Significant vibration in footwell and in steering wheel at speeds of 90-130kph. Sometimes the vibration ceases for a few minutes when driving over small cracks in the highway. Almost as if some suspension componen/bushing etc is being jarred into the "correct" position. Should we rule out a simple balancing issue?

Not sure if related: I am also getting popping noise from the front end when turning, and over some bumps/dips. If I rapidly turn the wheel while parked, there is a popping/hollow type noise that sounds "loose."

Both swaybar end links were replaced last summer, as well as the PS outer boot, and the whole DS axle assembly. The noises I am hearing do not resemble what I heard when I had bad endlinks last year. Though I guess I can't rule it out entirely.

There is axle grease on my wheels. Boots are intact. It seems the grease has been squeezed out, perhaps a loose clamp, or it was overpacked. Could low grease be the culprit? I imagine significanly low grease will cause balancing issues, but intermittently?

All of these symptoms only began to occur over the past quarter, and not around the time of the above parts replacements.

I am taking the vehicle into an indy today to figure out whats up. However due to the multiple sysmptoms and the general difficulty of diagnosing suspension issues, I was hoping you fine folks could give me more ideas I can discuss with the mechanic.

Thank you all in advance for any input.

Mechanic says replace front differential and both axles.

I do not believe it. Am I in denial?

The whole differential too? I would go to another shop and get a second opinion. Obviously, without mentioning what the first shop came up with.

Unfortunately, I don't have anything to add. Hopefully, somone will chime in that has experienced similar problems.

I certainly intend to get a second opinon. I just don't feel a half hour inspection is reliable enough for such a tall order as replacing the dang differential and 2 axles, one of which is only 1 years old.

From my experience, I have little faith in indy mechanics and their diagnosis abilties. I also think I "talk" too much (ie. saying what I think it could be, symptoms), and perhaps unfavourably influence the conclusions of the mechnics.

Maybe I should just bite the bullet and take it the dealer for a hopefully more accurate diagnosis.

ADDITION: It may be of note, that the vibration/shake at highway speeds is consistent when on cruise control. ie. accelerating does not make it worse unless I am increasing speed to the "vibration zone." Past 130kph the vibration is gone. Below 90kph the vibration is gone.

I would think that if there's a problem with the diff that you would notice it all the time - not just at certain speeds. Let's see what others think.

Well I think if you have grease all over, and popping while turning, you might as well change the axles. Go from there. Not sure what else to add.

My 2 cents (and probaly not worth every penny): When I read just the first two sentences I am reminded of a couple of problems I have had that gave me the same vibration results (not on an X5 though) ... lost wheel weights, and a badly mounted wheel on the hub. Perhaps start with those ... simple and cheap. Also, again not the X5, I have had axle grease splattered everywhere from an overfill (including the ABS sensor FWIW).

+1 on the CV axles being the source. Those are also balanced from the manufacturer and if grease is all over, the popping and clicking is the CV joints.

Yea you guys are probably right. It is just annoying how the boots are intact, and yet the damn grease leaked out and the cv's are making noise. I thought the CV's fail when debris and moisture is able to get into the joints and grind it all up.

These two videos describe the noise I get one the vehicle is parked:

item 300402773538 on ebay - new steering rack bmw X5 noise - YouTube
e46 lower steering UJ knocking noise - YouTube

^^ sounds to me like u-joint/steering column. At this point what is not wrong with my front end.

Well made CVs fail when the boots fail. Poorly made CVs fail due to being poor quality.

What did you do last year? I remember your questions about the CV then. You wanted to use a cheap replacement axle shaft and the shop advised you that it could cause a differential failure. Same shop now?

http://www.xoutpost.com/bmw-sav-foru...-safe-buy.html

I would replace both axle shafts, and not with cheaply made aftermarket parts. See if that fixes it, or if the differential is the next step.