How long do shock absorbers last?

[R2D2]

When should you change the shock absorbers on a Mercedes??

 

[Shude]

When they are broken. Was still on the original ones on my previous car at 140k miles, seemed fine.

Some people say they should last about 100k miles. I think it very much depends on how much town/motorway/pot-hole punishment they've had, bit like everything else on the car really

 

[R2D2]

So at 73,000 I might not need to change them then.

 

[jimmy]

I think something like 60% of cars have worn out shock absorbers, but because they are only an MOT failure if they are visbily damaged or leaking, nobody bothers to replace them.

Modern cars have gas filled shocks so you cannot see if they are leaking anyway. I think most manufacturers reckon on replacement every three years.

 

[R2D2]

OOps so nearly 5 years then IS too long. Youve done yours havent you Jimmy?

 

[jgevers]

Hi,

Dampers are used to control the energy from the spring and to some extent to assist the spring and antiroll bar under low speed compression. They consist of hydraulic valves that move in oil. The shims and seals wear over time. If you look at dampers that have done 40k road miles on a damper dyno, compared to a new damper, it has lost more than half of it's efficiency.

Because the wear happens gradually, you don't notice it much, other than diagonal pitching when cornering fast and general floatiness. The revelation comes when you fit new dampers. It suddenly feels like you are driving a new car.

regards,

Job

 

[Sp!ke]

My 13 year old car is still on original shocks. The damping on the rear is now starting to display signs of old age but hey, can't complain.

I'll be changing shocks and springs all round (and hiring your spring compressors Jimmy) sometime in the first quarter next year.

 

[Will]

I think Job has summed it up nicely,

Trouble is, most people these days (excluding the majority of "enthusiasts" such as ourselves), are skinflints when it comes to cars. Most people will either drive cars until they notice a problem, and then just get it fixed. Items like shock absorbers don't get thought about, and unless they are obviously broken (eg, the 'bounce' test ) they won't be changed!

I find it interesting to hear figures such as these mentioned, as 40K doesn't sound like a lot of miles, but if you consider the facts that although roads are supposed to be smooth and bump free, how many places can you go these days without speed humps etc!

I don't think that there is any widespread, easy way of effectively/accurately testing shock aborbers, or surely they would consider including it for the MOT test?

I think the realisation comes when you fit new ones to a tired car. I certainly noticed an improvement when I replaced them on a 190E a few years ago.

Cheers,

Will

 

[mickl]

an old mechanic friend of mine used to say a rule of thumb was 1% wear per 1k mileage.

 

[jimmy]

I don't think that there is any widespread, easy way of effectively/accurately testing shock aborbers, or surely they would consider including it for the MOT test?

I have seen an early prototype of an electronic shock absorber tester that is planned to go into production and eventually be part of the MOT testing.

You are right though, there is no easy way of testing shocks but when you do change them you really do notice a difference.

 

[Will]

I have seen an early prototype of an electronic shock absorber tester that is planned to go into production and eventually be part of the MOT testing.

You are right though, there is no easy way of testing shocks but when you do change them you really do notice a difference.

I suppose that even then, it may be similar to a lot of the MOT rules - eg, bare minimum purely for 'road safety', rather than comfort/performance.

Eg, you can drive on tyres with less than 2mm of tread remaining, but who would really want to?!

Cheers,

Will