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The car is a 2006 Avant with 157,000 Km on the odo. Recently it has started to have a rumbling noise that appears to be emanating from the RF (passenger side front) wheel area. The noise starts to be noticeable above 75 km/hr and is quite loud when driving at highway speeds of 100 to 110 km/hr. It is definitely speed related.
I have checked under the hood for possible noise sources but the problem appears to be wheel/ suspension related. To that end, I have inspected the in board and out board CV joints which appear to be good. I have verified the tire pressure all around to make sure it was not a pressure imbalance issue. Also, I have checked the wheel hub for possible bearing play and most of the suspension points for play and torn boots. All appear to be in good shape.
There appears to be an RF alignment problem as the outer edge of that tire was free of tread from scuffing, so I put on the spare which has good even tread but it did not make a difference to the noise. The LF tire is still in good shape but the car still makes the squidgy/ thrum noise I have always associated with Audi so I am not sure what I need to replace. Any suggestions?
So you lifted the car up and grabbed the tire by 3 and 9 o'clock and shook hard for play? And did the same for 6 and 12.
Did you grab the cv axle firmly and shook hard for play?
All bushings on every control arm point is not worn?
Then I'd check alignment. Tracking down vibrations are tough.
I did the tire wiggle test. No play found.
The CV axle inspection was a visual/ feel for boot cracks and tears, so I will have to try the shake test.
The check of the bushings was a visual/ feel thing as well.
About a year ago, the power steering hoses burst and the mechanics who worked on it, may have disturbed the alignment and not checked things. There were a few minor issues with the car after I got it back.
I have noted in a few other posts, that I may need to lift the whole car and engage the drive to verify the bearings, so I will try that this weekend and post later.
The shaking of the wheel with the car raised to check for worn bearings will suffice. It won't make a difference if your in gear.
While you have the car up shake and twist all suspension components for play. That goes for the cv axles as mentioned.
Not sure if I'm understanding you right, but if you meant you're going to engage drive with all four tires raised and engine on letting the wheels rotate, DO NOT forget to brake when shifting in and out of gears(auto trans). If you don't you'll end up grinding gears to a halt. There's no ground contact to stop your wheels from turning. I've done this by forgetting and it's not a great experience...totally lame.
Not sure if I'm understanding you right, but if you meant you're going to engage drive with all four tires raised and engine on letting the wheels rotate, DO NOT forget to brake when shifting in and out of gears(auto trans). If you don't you'll end up grinding gears to a halt. There's no ground contact to stop your wheels from turning. I've done this by forgetting and it's not a great experience...totally lame.
Fortunately for me, the car is a 6 speed manual.
I have had an experience on another car where there was a noticeable whine from the bearing at speed but absolutely no play in the wheel when lifted and stationary, so that is why I will engage drive with all the wheels lifted. I will also take the time to check the propeller shaft under the car this time. Getting at that part will be ugly since it's concealed by the exhaust pipes and heat shields.
Today, I lifted the car and put it up on blocks so that I could run all four wheels and see if there would be a definitive source of the noise. While nothing was really evident from the outside, there was a really strong indication that it was in the RF part of the car. Everything was checked. All drive shafts, suspension points etc. but still no definite defect.
I have decided to do the RF bearing as the noise is getting worse when driving. The trouble now is to get the tools to take off the main hub bolt and then the bearing carrier bolts. A pox on Audi.......
The axle bolt isn't difficult if you have a breaker bar. It's a stretch bolt so technically, you're supposed to change it after any maintenance, Not many do.
The bearing is held on by four triple square bolts. They're on there tight with a bit of factory applied locktite. I used an impact wrench to get them off. So if you're doing it with hand tools be careful not to shear them.
Note if the bearings are good and no wobble, with the tire off, the hub shouldn't spin freely. If you give the hub a whirl and it spins continously then they are bad.
Changing them is a different task. Removing is a bit involved and reapplying you'll need a press.
The axle bolt isn't difficult if you have a breaker bar. It's a stretch bolt so technically, you're supposed to change it after any maintenance, Not many do.
I purchased a kit that includes all the bolts including the axle bolt. Using a 3 foot breaker bar and standing on the end I was not able to budge the bolt. Just stripped the 17mm Hex tool instead. I am glad the bolt is intact and not damaged.
The bearing is held on by four triple square bolts. They're on there tight with a bit of factory applied Locktite. I used an impact wrench to get them off. So if you're doing it with hand tools be careful not to shear them.
A Sunday trip to Princess Auto was required to find the correct tools including the triple square bits. (A pox on Audi for using them!) A bit of localized heat on the bolt will make the Locktite more co-operative however it was late in the day when I got back, so I will have to tackle this later on in the week as I am missing a ball joint removal tool, which I still have to source.
Note if the bearings are good and no wobble, with the tire off, the hub shouldn't spin freely. If you give the hub a whirl and it spins continuously then they are bad.
The car is all wheel drive. How much drag does the transfer case apply to the CV joint shaft? Will it still spin as freely? There is no tire wobble whatsoever so I was thinking it might be the bearing in the transfer case as that is where the noise was most noticeable when I had the whole car running while on blocks.
Changing them is a different task. Removing is a bit involved and reapplying you'll need a press.
I have a 10 tonne press, having learned the hard way on another car...... Also, putting the bearing in the freezer for 24 hours is a good way to help the install process.
Finally finished the job of dismantling the bearing carrier, replacing the wheel bearing and then re-assembling everything. After double checking the torques of all the bolts holding everything together, I put the wheel on and took the car for a test drive. A whole lot quieter than before with just the bearing being replaced on the one side. The pictures below illustrate the source of the problem.
Bearing viewed from the front side
Back view
When I was removing the CV joint hub from the wheel hub, I found quite a bit of oil in the cavity. Initially I thought the CV joint was leaking lubricant. After pressing out the wheel hub and examining the bearing, I discovered the bearing seals were completely worn out. Water had seeped in and had washed the grease out causing the failure.
08-05-2016, 11:51 AM
Noise in front end from what part?
