The car has 130K miles on it. Recently I have noticed a vibration and thought it was a tire needing to be re-balanced.

The condition does not occur until above 55 MPH. It seems to be throttle sensitive ie. When accelerating hard it is quite severe the vibration; it is not as bad when de-accelerating and if I apply a light throttle ( no acceleration or de-acceleration loads) the vibration is not detectable.

Could this be a CV joint failure ??? Is it more likely to be on the drive shaft or an axle ? I have jacked up the car, but could not pick up any
indication, rotating the 4 wheel back and forth.
I have yet to crawl under the car and check the drive shaft CV's.
Thx.
art

And you checked the control arms and all the bushings?
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I'm stuck on Volvo and Volvo's stuck on me....when it comes to FWD I always listen to the "Oracle of Minnesota'

Thanks to everyone for the additional suggestions, which I will follow-up on.
Art

Swap the wheels, front to back, first. Most out of balance conditions do not happen until over 50mph. You could have lost a lead wheel weight? The new ones are glued on the inside of the rim.

I wouldn't point to the axle yet, even those with worn boots and sand in the joints don't wobble up and down, they make a grinding noise.
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Keeping it running is better than buying new

Before I throw in the towel on this issue, I have done the following since the original post, to locate the vibration:

--rotated front tires to the rear, road tested and then;
-- had all four wheels re-balanced

No detectable change in when the vibration begins, the magnitude of it and what seems like the location.

Car is smooth, all speeds up to about 65 MPH. Then vibration begins. The vibration has always seemed to emanate from the drivers side front of car.

-- cannot detect any excessive slop/movement or noise when rotating
back and forth the axles and driveshaft CV joints.

Can a wheel bearing be a player .... ??? why would it begin to be a problem at 65 ??
Thx.
Art

Just a thought, check the center support and bearing on the propshaft.
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Keeping it running is better than buying new

"...check the center support and bearing on the propshaft...."

Good idea. Me understanding is that some people totally remove the center prop shaft when they suspect something like that. I don't know all the ins and outs and considerations when doing that.

Conversely, I wonder if it's permissible to remove the front axles and propel the car with just the rear wheels as a test to see if the vibes diminish with the absence of the front axles.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

There is a differential between the front axles, if you remove one front axle, none of the wheels will turn.

You could remove the propshaft...

But the center bearing and rubber hanger is easy enough to check. The problem is trying to replace either of them. Someone was successful in modifying a 740 hanger to fit a 1998-2000 XC. Most send the propshaft to a company in the Denver area for a rebuild.
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Keeping it running is better than buying new

Ah, I see.

"...Most send the propshaft to a company in the Denver area for a rebuild...."

That might be the shop I talked to on the phone a couple days ago about rebuilding the axles on my wife's S80. The bummer is that they don't stock any Volvo cores so I have to tear the car down and send them mine, resulting in a car that's inop for about two weeks counting shipping time to and from. They talk a good story on the phone, like maybe they really know what they're doing.

http://www.cvjreman.com/

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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

http://coloradodriveshaft.com/volvo.htm
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Keeping it running is better than buying new

Again thank you all for the advice I have received. Klaus, I hope to check out the drive shaft this weekend and will contact the site you forwarded as needed.

I need to look up what it takes to drop the drive shaft assembly... youtube

I will keep you posted.

Art

You could try swapping tires front-for-rear, but what you're describing is a classic case of a front CV joint failure.

If that's what it turns out to be, the best solution is to replace it/them with OE GKN unit(s) - super costly.

Second best is a "properly" rebuilt OE axle (not just a cleaning with new grease and new boot, but a carefully re-machined CV joint) - not quite as costly as new.

Third best is a used OE axle with low mileage. (Good luck finding that one!)

Worst solution is to install the typical Chinese junk they sell at the local auto parts store.

I'm struggling through this same scenario on our 2005 S80 w/185,000 miles as we speak. I think I'm going to try the local wrecking yard for $35/axle. If nothing else it will give me two OE cores that I can send in for rebuilding without having to disable the car for a week or two.

Good luck.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

That is not a lot to go on.

We had a belt separation in a tire that looked fine. Running my hands over the surface of the tire detected a small depression in the face of the tire. Shifted or broken belts can usually be felt in the tread. Bulges and twists are most common, but I guess dips happen too. You have to be careful with steel belted tires because the wire can poke out through the tread.

Is the vibration front or rear ? Does it change if you swap the rear tires to the front ? How are the u-joints in the drive shaft ? A bad CV joint usually makes noise when you are turning.

Greg

Tires were inspected during re-balancing for indication of belt failure...
nothing evident. as note in other post moving the tires did not seem to change the vibration location.
Thx.
Art