Keeping the ride pleasant on your car is the work of a double act. You have the springs of course, but then you have the shock absorbers. Without them the car would just be a wobbly mess and the springs would compress at the mere mention of load or a rough surface.
As such, your shocks are very important indeed. But how do you know when you need to replace them, and when that time comes around, how do you go about it? Worry not, as Haynes has your back.
How much are shock absorbers?
The cost to replace shock absorbers will vary widely, depending on the type of vehicle, the brand of shock absorber and whether it's a regular hydraulic piston or an adjustable shock absorber, with magnetic particles in the fluid – the latter can cost hundreds of pounds each. Your more basic shock absorbers cost well under £100 each, depending on the brand (such as Monroe or Bilstein) you opt for.
Where are your car’s shock absorbers?
Every car is different. That said, the most common style of suspension is the MacPherson strut, which means the shock is part of the strut structure itself. It sits within the spring, which is a great design as it saves a great deal of space. Of course, other cars differ, so check your Haynes manual.
As for the rear, MacPherson is again common. However, so is a separate shock. You’ll see it bolted at the lower end to the beam/axle and bolted at the top to a mount on the body. The spring will sit in separate ‘cups’.
When should shock absorbers be changed?
There is no hard and fast rule to how long your shock absorbers should last. Every car is a different weight, every car is driven by a different person, and every car is subjected to different road conditions and surfaces.
Despite this though, we can say that in larger cars with age-appropriate mileage, you’re looking at around five years of general use. If the car had had a gentle, low mileage life, that can be more.
Small cars with average to low mileage could see 10 years out of a set of shock absorbers. If a car has higher than average mileage, then obviously the life expectancy goes down.
How can you tell your shocks are gone?
Remember when your dad was looking at used cars, and he’d lean over one corner of the vehicle and bounce it? He was checking the shocks. It’s the simplest way. Push the car down and it should rise back up and stay. If it wobbles about like jelly at a kid’s party, the shocks are goosed.
The other way to check if they’re on their way out is to get under the car and have a look. Shocks work via pressure acting upon an oil within the shock body. Shocks are sealed units. So, if you look underneath and can see a coating of oil on the shock’s body or, even worse, an obvious leak, then that means your shocks are failing.
Finally, there’s the way the car drives. Even the most softly suspended of cars will have some firmness to it. It has to – that is what functional suspension does.
So, if the car it rolling excessively out of corners, if it’s wobbling about when you brake or accelerate, and if it generally feels ‘disconnected’ to drive, shocks could well be to blame.
What tools do I need to change my shocks?
Happily, you shouldn’t need any specialist tools to change your shocks. A trolley jack, axle stands, sockets, spanners and a torque wrench will do you fine.
Struts are more involved and require a spring compressor to remove.