KfabR8
August 18th, 2009, 03:38
Just out running errands to day in my ride. Ran through a fun little road we call "The twisty road" at about 60%. Nothing serious, nothing slack.
Never hit any bumps or pot holes either.
Came to a four way stop intersection and waited my turn.
As I got rolling (fortunately I was being very relaxed about take off - just eased out on the clutch) the rear end suddenly had a very loose feeling - as if something had let go.
I throttled off and then gingerly rolled back into the throttle - yea, the rear end felt as if it were trying to steer a little bit.
HUH???
I wiggled the steering wheel a bit back and forth and the right rear side of the car seemed to wag much more than I'd ever felt.
I pulled over and inspected the rear end of the car - making sure that all the suspension components were okay. Seemed like all was good.
I visually checked all the bolts and nuts that can be seen through the rims and by laying on the ground under the back of the car. Nothing seemed out of place.
I then sat down and pushed on the leading and trailing edges of the right rear tire with my feet - the wheel wiggled. Uh oh! :bigeyes:
I had a feeling that the lower rear link, that controls the toe of the rear wheels, had an issue.
Fortunately I was only about 2 miles from the Audi dealership that services my cars. I very, very carefully drove to the shop making sure that I didn't have any sudden input from throttle or brake. It kept the torque of the rear wheel on the bearing carrier/housing at a minimum.
Sure enough, the mount for the link had come out of the aluminum housing of the rear carrier. The nut and bolt were still in the bushing.
The bushing had worked it's way out of the aluminum casting.
Defect?
Just use and street abuse?
Not sure yet.
Audi's covering it - all warranty. (wouldn't expect anything less, as this is a part/manufacturing failure) They're red-labeling in a new right rear bearing carrier/rear housing. Hopefully it will be here by the end of the week.
I'm looking forward to getting my hands on these parts and inspecting them to see what caused the failure. The Mechanical Engineer and machinist in me has my curiosity running on high.
I'll try to get some pix of the parts and pass on what Audi tells me about the problem as I find out more.
Anybody else have this sort of failure?
I've been thinking about it - track cars, while seeing a high level of stress, generally see a smooth world. The loads are not shock loads, but ramp up and down as the car goes around the course. Throttle, braking, lateral loading are all factors that could attribute to a failure such as this, but in general, for a bushing that is tolerance fit into a cast part to get pulled out via these loads isn't going to happen.
So what about street use (abuse)? Streets are rough, nasty environments. There are always holes, ridges, cracks and such that jar the vehicle.
The streets around here are not to terribly bad and I'm so familiar with them that I know where to dodge and dart to avoid nasty stuff.
We just finished a 3,700 mile trip. I had a couple fairly major thumps given via road work and such, but nothing that would rip out a suspension component.
W/o getting to inspect the piece, I'll stand on the idea that I just happened to be one of the lucky individuals that got a slightly defective piece. (let's hope so).
I guess the only thing that really worries me about it is that, as far as I can tell, I have many more miles on my car than the average R8 owner.
It's the drivers like me, that get out and use their machines on a daily basis, in all conditions, that find the little engineering misses.
No matter how much testing the factories do, it's usually the consumer that ends up finding little nuisance things. (I've seen this happen in the motorcycle industry countless times)
I'll be keeping a very close eye on the left side now.
As stated, I hope this is a one-off issue.
Never hit any bumps or pot holes either.
Came to a four way stop intersection and waited my turn.
As I got rolling (fortunately I was being very relaxed about take off - just eased out on the clutch) the rear end suddenly had a very loose feeling - as if something had let go.
I throttled off and then gingerly rolled back into the throttle - yea, the rear end felt as if it were trying to steer a little bit.
HUH???
I wiggled the steering wheel a bit back and forth and the right rear side of the car seemed to wag much more than I'd ever felt.
I pulled over and inspected the rear end of the car - making sure that all the suspension components were okay. Seemed like all was good.
I visually checked all the bolts and nuts that can be seen through the rims and by laying on the ground under the back of the car. Nothing seemed out of place.
I then sat down and pushed on the leading and trailing edges of the right rear tire with my feet - the wheel wiggled. Uh oh! :bigeyes:
I had a feeling that the lower rear link, that controls the toe of the rear wheels, had an issue.
Fortunately I was only about 2 miles from the Audi dealership that services my cars. I very, very carefully drove to the shop making sure that I didn't have any sudden input from throttle or brake. It kept the torque of the rear wheel on the bearing carrier/housing at a minimum.
Sure enough, the mount for the link had come out of the aluminum housing of the rear carrier. The nut and bolt were still in the bushing.
The bushing had worked it's way out of the aluminum casting.
Defect?
Just use and street abuse?
Not sure yet.
Audi's covering it - all warranty. (wouldn't expect anything less, as this is a part/manufacturing failure) They're red-labeling in a new right rear bearing carrier/rear housing. Hopefully it will be here by the end of the week.
I'm looking forward to getting my hands on these parts and inspecting them to see what caused the failure. The Mechanical Engineer and machinist in me has my curiosity running on high.
I'll try to get some pix of the parts and pass on what Audi tells me about the problem as I find out more.
Anybody else have this sort of failure?
I've been thinking about it - track cars, while seeing a high level of stress, generally see a smooth world. The loads are not shock loads, but ramp up and down as the car goes around the course. Throttle, braking, lateral loading are all factors that could attribute to a failure such as this, but in general, for a bushing that is tolerance fit into a cast part to get pulled out via these loads isn't going to happen.
So what about street use (abuse)? Streets are rough, nasty environments. There are always holes, ridges, cracks and such that jar the vehicle.
The streets around here are not to terribly bad and I'm so familiar with them that I know where to dodge and dart to avoid nasty stuff.
We just finished a 3,700 mile trip. I had a couple fairly major thumps given via road work and such, but nothing that would rip out a suspension component.
W/o getting to inspect the piece, I'll stand on the idea that I just happened to be one of the lucky individuals that got a slightly defective piece. (let's hope so).
I guess the only thing that really worries me about it is that, as far as I can tell, I have many more miles on my car than the average R8 owner.
It's the drivers like me, that get out and use their machines on a daily basis, in all conditions, that find the little engineering misses.
No matter how much testing the factories do, it's usually the consumer that ends up finding little nuisance things. (I've seen this happen in the motorcycle industry countless times)
I'll be keeping a very close eye on the left side now.
As stated, I hope this is a one-off issue.