vincent white said:
I purrchased my 997 with 35,000 miles and the suspension was knocking, after the dealer changing loads of parts they discovered it was the shocks. They charged me £1,500 as it was a wear and tear item how much have they quoted you?
I would put money on it that the knocking was failed bushes at either end of the shocks, rather than the shocks themselves - how can fluid going through a hole cause a knocking noise?
The problem is that the shocks and springs on a 911 generally are changed as a unit and they comprise of all the following parts that could be the cause of the problem:Lower bushes, Upper bushes and spring mounts, dampers themselves, lower spring mount, anti-roll bar mounting points, and of course the springs.
Because UK dealers do not generally have the correct equipment to check the operation of dampers, suspension problems are usually quoted as 'shock absorbers' and of course changing all the above components cures the problem in 95% of cases and so the myth is perpetuated.
I had a long discussion with a Porsche engineer in Germany, and I was told that the TuV test (equivalent of our MoT) includes a proper damper test, for which the garages have to have the correct equipment, and I was told that they very rarely need to change Porsche OEM shock absorbers at less than 200,000 kms on a 996 - unless they are actually broken.
Bearing in mind that I had actually booked my car in in advance to have new suspension all round, the dealer concerned had no motive to turn away €3000 worth of work that they had already got parts and time to do, so I am inclined to believe them - especially as I saw the test being done, and the results.
Worn bushes, weak springs, worn track rod ends, and anti-roll bar drop links are another story and it is usually these that are the real cause of suspension problems, but are cured by fitting new shocks (except track rod ends) which are often not actually needed.[/list][/list]