When to replace Shock Absorbers?
Having been a specialist in suspension for over 15 years, one thing that strikes me as very odd, is that no provision is made in the annual MOT test for shock absorber (damper) performance.
The shock absorber damps the oscillations of the spring, and ensures the tyre has maximum grip with the road, or track. A worn shock can cause poor road holding, longer braking distances and a bouncy uncomfortable ride. They are dangerous when worn.
The MOT tester only looks for signs of oil loss, a light misting of oil would usually be an advisory notification, where as heavier loss of oil would see the car fail the MOT test.
However, it is not uncommon for a new twintube damper to experience some loss of oil, shortly after fitting. Conversely, it's quite possible for an old damper which has lost all damping force, to have been cleaned of any lost oil, and because no test is made of its function, it could still pass the MOT.
Therein lies the problem. Taking a wild guess, it wouldn't surprise me if half of the cars on the road had at least one damper that was performing badly. When you change your brake discs you always change as a pair and you can easily see when they are worn out.
One solution to the problem, would be a bi-annual test of the vehicles shock absorbers on a shaker rig. Unfortunately, these kind of rigs are extremely expensive, and you would probably have real resistance from testing stations, if you asked them to invest in such equipment.
So the easiest solution is to replace your dampers when they are likely at the end of their useful service life, putting a finger on when this is, is difficult as it depends on the road surface and manner in which the vehicle is driven. However something like 40 - 50k miles would be about right.
Please get in touch with us for a quote to change your shocks. If you want to make your car safer and sportier at the same time, a well installed set of quality coilovers could be just the ticket for an enthusiast.