Shock Absorbers & Struts

The old bounce test still works as a rough guide: push down hard on one corner and release, and a healthy damper lets the body rise and settle in about one movement, while a worn one continues to oscillate. Better evidence comes from inspection and from how the car behaves. Look for an oily film on the damper body, which means a leaking seal, and watch for cupped tyre wear, excessive nose dive under braking and a floating feel over undulations at speed.

Across an axle, yes, and it is not a sales convention. Damping controls how quickly each tyre returns to the road, and a new unit alongside a tired one gives noticeably different grip and weight transfer on the two sides of the car, which is at its worst in the emergency manoeuvre where you need it least. Replacing both is also cheaper in labour than doing one now and one later. There is no need to do all four at once unless all four are worn.

Function rather than principle. A shock absorber only damps movement, with the wheel located entirely by suspension arms. A strut damps and locates: it replaces the upper arm, carries the spring, takes side loads and, on most designs, sets camber. That makes struts larger and stronger, and it means a bent strut changes wheel geometry while a bent damper simply stops working. This category lists rear shock absorber assemblies and front strut assemblies separately for that reason.

Read the listing and think about your tools. A complete strut assembly arrives with spring, top mount and bearing already assembled, which removes the need for a spring compressor and refreshes the mount and bearing at the same time. A bare damper is cheaper and requires the old spring and mount to be transferred, which needs a proper compressor and carries real risk if the tooling is wrong. Where the top mount is also worn, the complete assembly is usually the better purchase.

Because they protect the expensive part. The dust boot keeps grit off the polished piston rod, and once grit reaches the rod it scores the surface, cuts the seal and lets the oil out, which is how a healthy damper becomes a leaking one in a single winter. The bump stop catches the final portion of travel so the damper is never driven to its internal limit. Both are cheap, both are usually destroyed on removal, and both belong in the same order.

No. A telescopic damper is a sealed pressurised unit, and once the rod seal has failed the oil escapes, gas pressure is lost and the valving no longer works as calibrated. There is no seal kit and no way to recharge it in the field. Replace it, and replace its partner on the same axle. Where the leak was caused by a torn dust boot, fit new boots on both sides or the new dampers will follow the old ones.

Dust boots, dust covers and bump stops sit right at the bottom of the range. Rear shock absorber assemblies are moderate. Front strut assemblies cost the most in this category, since they are larger and, where supplied complete, include the spring and top mount. The live minimum and maximum are shown in the band at the top of this page. Because these are axle pair purchases, price both sides together when planning the job.

Rear dampers are usually a straightforward two bolt job on a supported vehicle. Front struts are a different matter: the assembly carries a compressed spring holding enough energy to cause serious injury, so dismantling one demands a proper spring compressor and correct technique, and improvised tools have killed people. If you are fitting a bare damper, use the right compressor or have the strut assembled by a workshop. Complete strut assemblies avoid the issue entirely and are worth the difference for home fitting.

Usually because something around the damper was reused. A tired top mount and bearing left in place will knock and creak on a brand new strut, an old bump stop that has hardened will thud, and a bolt torqued with the suspension hanging can preload a bush. Fit new mounts, bearings, boots and bump stops with the struts, torque everything at normal ride height, and check that the spring is seated correctly in both its upper and lower cushion pads.

They need the correct part and often a workshop step. An electronically controlled damper carries a solenoid or valve actuator and a connector, and the control unit monitors the circuit, so fitting a conventional damper in its place sets a fault and disables the system. Some vehicles also require a calibration after replacement. Check whether your car has a connector at each damper before ordering, since adaptive and passive versions look similar and are entirely separate references.

They may bolt on and behave differently, which is the trap. Valving is calibrated to vehicle weight, wheel and tyre size and suspension specification, so a damper from a lighter version of the same body will feel underdamped and one from a sports specification will feel harsh, with no fault code to explain either. Match the OE number from the old unit, and where the reference brings back nothing, send it through the quote form to have the catalogue checked.

Yes. Dampers are long and heavy, so the quote covers carriage as well as the part, and adaptive units are quoted more often than conventional ones because each is matched to a specific chassis calibration. Give the number and say which axle and side. Order in pairs for the same axle. A new damper on one side and a tired one on the other gives uneven rebound that shows up as a pull under braking. Ask whether a complete strut with the spring and top mount already assembled is available, since that version removes the need for a spring compressor.