Steering Vibration

[OmahaJoe]

I bought my 2005 X5 3.0 used a couple years ago and have run through the gauntlet of X issues, but love the truck nonetheless. I've got 74K on it now. Lately I've noticed a significant vibration at higher constant speeds (usually 65-70) on the highway while going up slight inclines. The vibration can be felt mainly in the front end, pedal, floor, etc. and immediately goes away when I take my foot off the pedal. It doesn't happen all the time, just every now and then, but seems to be getting more frequent of late.

After reading through similar posts, I'd like to provide a little history and see if I'm heading in the right direction...

1. The first time I noticed the problem was about 2 months ago driving cross country. It happened a couple times during a 3 day trip.
2. My tires were going bad, so I decided it was time to get new tires. I have stock rims and bought Bridgestone Alenzas from TireRack.com. Had wheels balanced/alignment done at a Goodyear service center. Problem persisted. Other related items I've done over the last two years are as follows...
3. Replaced front tension struts about 1.5 years ago after bushings cracked and started leaking fluid (OEM parts).
4. Replaced front CV Boots about 1 year ago based on recommendation from my indy. Boots hadn't cracked but were getting close, and everything inside looked fine.
5. Replaced front rotors/pads and rear pads 1.5 years ago.

Based on what I've read so far it looks like the culprit(s) could be the flex disc (guido), center support bearing, engine mounts, differential carrier bearings, or drive axle.

I've ruled out sticking caliper given this occurs during constant speeds and stops immediately when I take foot off the pedal. I'm also pessimistic on a bent rim or balance issues as this only happens going up inclines, never on level/declines.

Before I start going through the potential list above, any recommendations or insight would be greatly appreciated.

Cheers,

[OmahaJoe]

Lots of views and no replies. Anyone with insight before I start taking things apart? Thanks again!

[bds325is]

I was struggling w-vibrations at 85 mph, so I put it on the lift . I removed the wheels and deactivated traction control, that allowed me to drive at any speed and have someone look and listen at everything under my x.
In my situation , the front transfer case bearings were failing.

[DallasGV]

I'm definitely not an expert and just throwing this out, but have you tried different RPM's at the 65-70 speed? If you can put it in a lower gear at that speed you should be able to tell if it's RPM or speed related.

[Big "J"]

OJ! Did you ever find the culprit to the vibration under power?

[OmahaJoe]

Left Front drive axle. The inner cv went bad. The trouble was that the boot looked ok and there wasn't any obvious cracks or signs that the grease had come out, so it might have been something that was gradual and took time to get to a point where it could be felt through the pedal. $900 at my indy mechanic and it drove like a dream. The stealer will probably charge you $1250+, and that's if they are honest and don't monkey around with a bunch of other stuff as they try to "find" the problem. As you'll see with this thread though, there's a handful of other issues that can cause these symptoms. Good luck!

[Big "J"]

Ok! I replaced mine with a reman a few months ago and rode good for a couple weeks. I damaged the center bore of my left wheel (minutely out of round) yet, could get the holes and lugs lined up and what appeared to be hub centric.

The persistent vibration was puzzling and am getting new wheels ordered to remove the obvious defect and narrow it down further.

Everything accept the air strut has been replaced with OEM in front (except cv axles).

If not the wheels, then the hubs and bearings are next?