Vibration at 35-40 mph after drive shaft replaced - 2008 Cayenne

[talbertc]

My drive shaft recently failed and I had it replaced. When I got the car back everything seemed ok. I was out of town when it happened so I drove about 5 hours back home after the replacement. My wife and I didn't notice anything unusual.

A day or 2 after returning home I noticed when I was get to 35-40 the whole car would start vibrating. This wasn't happening before. This time the ride felt like a very rough ride like I was riding on hard rubber tires or even something harder. This was not the same feeling at all as when the drive shaft was failing. The vibration starts and continues even when not accelerating. It also continues when I coast in neutral at 40-50 mph.

Tires are Nexen Radian HP 255/55R18 about 2.5 years old. So I had the tires balanced and replaced brake rotors and pads a few days ago. They checked the drive shaft and said it looked like everything with the replacement was ok.

I got the car back yesterday and it's still a vibration. Almost like a roar or hum but a very definite high speed vibration going on. I let some air out of the tires thinking that maybe that would help me determine if it's the tires. They were at warm 52 front and 44 back. I dropped them down to about warm 46 front and 40 back. Still vibrating but at a slightly higher speed.

This seemed to come on all of a sudden adn several days after the drive shaft replacement. I'm not convinced it is connected to the drive shaft replacement but that sure is a big coincidence.

Could my tires be the culprit? They still have good tread.

Anyone have any ideas?

[JFP in PA]

My drive shaft recently failed and I had it replaced. When I got the car back everything seemed ok. I was out of town when it happened so I drove about 5 hours back home after the replacement. My wife and I didn't notice anything unusual.

A day or 2 after returning home I noticed when I was get to 35-40 the whole car would start vibrating. This wasn't happening before. This time the ride felt like a very rough ride like I was riding on hard rubber tires or even something harder. This was not the same feeling at all as when the drive shaft was failing. The vibration starts and continues even when not accelerating. It also continues when I coast in neutral at 40-50 mph.

Tires are Nexen Radian HP 255/55R18 about 2.5 years old. So I had the tires balanced and replaced brake rotors and pads a few days ago. They checked the drive shaft and said it looked like everything with the replacement was ok.

I got the car back yesterday and it's still a vibration. Almost like a roar or hum but a very definite high speed vibration going on. I let some air out of the tires thinking that maybe that would help me determine if it's the tires. They were at warm 52 front and 44 back. I dropped them down to about warm 46 front and 40 back. Still vibrating but at a slightly higher speed.

This seemed to come on all of a sudden adn several days after the drive shaft replacement. I'm not convinced it is connected to the drive shaft replacement but that sure is a big coincidence.

Could my tires be the culprit? They still have good tread.

Anyone have any ideas?

I would start by making sure all the fasteners for the shaft are still tight; it is highly unlikely that you suddenly have a tire problem. I would also give the shaft a good shake while the truck is up in the air to make sure something else on it has not come loose. When something like this happens, always go back to the last thing touched.

[talbertc]

I have had someone take a look at the drive shaft and said everything looks good. Someone suggested the transfer box may have been damaged when the drive shaft was failing.

I had my tire guy drive it and he first thought it was tires but after driving it came to the conclusion it's not the tires. It's creating a harmonic vibration throughout the car. No specific area.

It looks like I'll have to make the 5 hour trip to take it back to the shop that replaced the drive shaft. I have a dealer close by but I generally don't have good experiences at dealers.

Any ideas would be appreciated.

[rosse]

I once replaced the center bearing on a audi quattro driveshaft, and it developed a similar vibration at certain speeds. It turned out that I missed one tooth of the center spline, resulting in a driveshaft that was no longer correctly balanced. So it looks to me that you need to have the driveshaft balanced and aligned correctly.

[mudman2]

at that speed it still could be the tires, have them road force balanced on a Hunter machine. Could be the side walls are flexing

[talbertc]

Put my cayenne on a rack and got it up past 35 mph and no vibration. Next logical step is replace tires. Did that and it still has the vibration as before.

I asked the tech about the new drive shaft being out of balance. He said it was never taken apart so that shouldn't be the problem.

Can a Volkswagen dealer work on a cayenne? We just had one open in our town.

[mudman2]

did you have them RF Balanced ?

[talbertc]

Latest on my vibration.

Since I don't have a Porsche dealer and the drive shaft is interchangeable I took the car to my local VW dealership. They looked at it and said there is a good bit of play where the drive shaft goes into the rear end. They suspect the rear end needs to be replaced.

Does this sound reasonable?

After having the drive shaft replaced and driving for 450 before the vibration started does that make sense?

If the rear end is the problem could it be from the drive shaft installation?