06 XC90 BAD Vibration Issue..

mhcrra1 · Post by **mhcrra1** » 13 Mar 2014, 13:26

Hi All,
Have been searching all over the place for help with this problem and really need some good advice, I'm stumped.
We have a 2006 XC90 V8 with 95k miles on it. It's my Fiance's car and she drives it daily....I'll give you a little background...
A couple of months ago while doing routine maintenance, I found the RR wheel bearing had too much play, so I changed it and in doing so had to change the RR axle (Used one) since it was seized into the hub. Around that time I also replace both lower control arm bushings on both sides up front (they were split and separated).
Shortly thereafter, my fiance said the car developed a HORRIBLE VIBRATION while driving normally. I took it out for a test drive and sure enough, once we hit 20mph there was a terrible vibration throughout the entire car. It is definitely NOT a tire vibration, but will rattle your teeth out.
Here's the kicker....while driving straight down the road, if I JERK the steering wheel to the left, the vibration completely stops then returns once going straight again. If I jerk the wheel to the right it has no effect on the vibration.
I was originally thinking LF wheel bearing possibly and with almost 100k on it, I decided to change the wheel bearing just in case....NO CHANGE!
Then I thought, maybe that used RR axle In put it was bent, so I got another one under warranty from my supplier and changed that out again....STILL NO CHANGE!
I am stumped here....been a DIY mechanic my whole life but this one really has me scratching my head.
I have read some possibilities on here....maybe one of the front axles, or possibly an engine mount......I don't know where to look next.
Does anyone have any thoughts, experience or ideas about this????
Sorry for writing a novel....thanks for any help!
Rob

Post by **JDS60R** » 13 Mar 2014, 13:42

If its AWD usually the front joint in the center shaft ( bolted to bevel gear /front diff) dries out and needs repacking or replacing.

Have a pro with safety training put it up on the lift with a volunteer in the cabin. run up to speed and watch vibrations from below.

left to right variance makes me think cv shaft issue but data shows you are right on time for the front , center shaft cv to dry up. I remove the shaft and repack both with top quality synthetic cv joint grease. Only a few retailers sell the boot if its ripped. I use www.driveshaftparts.com - he will sell you the joint and boot or just the boot if you call him.

mhcrra1 · Post by **mhcrra1** » 13 Mar 2014, 14:53

I've heard that those joints are problematic because of the heat from the CAT. I think I will pull the drive shaft this weekend and check it out. Do you think I should gamble on just repacking it....or replace the joint?

Post by **jimmy57** » 13 Mar 2014, 16:07

When you tap the end cap off after removing it you will know. IF it is rusty or has metal flakes then it needs to be replaced. That is usually at more miles than on your XC90.

mhcrra1 · Post by **mhcrra1** » 13 Mar 2014, 18:05

Thank you.....That's awesome info. I will dug into it this weekend and report back.

mhcrra1 · Post by **mhcrra1** » 15 Mar 2014, 15:54

OK, Update.....pulled the drive shaft off today and inspected the front CV Joint....I was hoping to find an obvious problem like all the grease dried up or rust or something...but found nothing suspect. There was plenty of grease in there and no rust etc. So, I repacked it, put everything back together and took it for a test drive.....PROBLEM STILL THERE!!!!! I am so frustrated at this point, I have no idea which way to go.
Since it had the snow tires on it, I thought I would toss a hail Mary and put the summer tires back on just to be sure it wasn't the tires....It wasn't! The vibration is still there.
When I was swapping the tires over, I did however, notice that the rear control arm on the right rear suspension was bent, it is bent up near the inboard mounting bolt. I can't believe that this would have anything to do to cause this vibration issue...but I am going to replace it nonetheless. I'm sure it's not good for the RR wheel.
So, after I get a chance to change that control arm and have an alignment done....WHERE DO I GO FROM HERE???? Is it possible that the right front CV shaft is bad, since that is the one with the additional support bearing I would tend to thing that would go first.
Any more suggestions would be great I am about bald from pulling my HAIR OUT!!!!
Rob

99VulvaS70 · Post by **99VulvaS70** » 20 Mar 2014, 07:41

If the problem began immediately after you did the work, then you have to start with those items replaced/repaired. it has to be a problem with a passenger side wheel bearing(probably the one you replaced). Before I replaced my rear driver side wheel bearing, whenever i would turn right, therefore shifting the vehicle weight to the left(driver side), the vibration would go away. driving straight or turning left it would continue.

mhcrra1 · Post by **mhcrra1** » 23 Mar 2014, 09:43

Ok, here is an update....THE VIBRATION IS STILL THERE!!!!
But, I took everything apart on the Left Rear, felt the new wheel bearing and it felt like there was a little "hitch" in it when turning it in my hands. So, to be safe, I got another new one and replaced it. At the same time, I replaced the Right rear "tuning fork" control arm because that was bent....I checked and rechecked everything in the RR suspension and all was well. Took the car out and BAM, vibration still there, just as bad.
Now, the one thing I have yet to do is get a full alignment since I have changed the front bushings and the control arm in the rear etc.....so I'm going to do that tomorrow, but I don't believe that would have ANY bearing on this problem.
Any more ideas? Thoughts?? Anyone?????? Going crazy trying to figure this one out.
Should I bite the bullet and change the other two wheel bearings that I haven't done yet?
Thanks....Rob

mhcrra1 · Post by **mhcrra1** » 24 Mar 2014, 06:23

Drove the XC90 into work today, gonna take it for an alignment after all of the suspension work I've done....listened/Felt that vibration the whole way in, trying to narrow it down, it definitely feels like it's originating in the rear of the car....COULD it be the rear differential??? Have those been known to be problematic???

mhcrra1 · Post by **mhcrra1** » 31 Mar 2014, 05:10

SOLVED!!!!!!!!!!!!!!!!!!!
If I had just listened to my gut instinct in the first place and changed the LEFT REAR wheel bearing like I had originally thought, I wouldn't have had to go through all of this anguish. After a FULL day of carefully cutting the old wheel bearing off of the CV shaft (what a horrible design the way they rust together), I was able to save the axle and change the wheel bearing..it's like a NEW CAR!!!!! Voila, problem solved.
Thanks everyone for your help and advice!
Rob