BMW 850CSi Front Strut Replacement Cost
How Much Does a Strut/Shock Absorber Replacement - Front Cost?
Strut/Shock Absorber Replacement - Front Service and Cost
A front strut, commonly called a MacPherson strut, is a suspension assembly that is integral to the front suspension and steering system of a vehicle. A loaded front strut assembly consists of two basic components, a coil spring and a shock absorber. The coil spring is in place to support the weight of the vehicle and to absorb large bumps. It allows the front suspension to travel up and down so that the vehicle body can remain stable. The shock absorber runs through the center of the spring and eases smaller bumps, dampens vibrations, and lends stability to the vehicle.
The two components of a loaded front strut - the coil spring and the shock absorber - are mounted together in an assembly that is connected to the vehicle's steering knuckle. The steering knuckle is attached to the steering system by way of the tie rod so that the front wheels can be turned. The top of the strut assembly bolts to the vehicle body in the strut tower, where it is able to pivot when the steering wheel is turned. The bottom is connected (by way of the steering knuckle) to the lower control arm and wheel hub. The strut assembly allows the vehicle suspension to rotate while it absorbs impact from rough terrain, helps maintain contact between the tires and the ground, and offers a smoother ride for passengers.
A vehicle with worn front struts can be driven, but the ride quality will be diminished, and, more importantly, the vehicle's handling will be compromised. A car's ability to remain level while turning, with traction spread between all four wheels, is dependent on the struts. As the condition of the front struts worsens, the ability of the suspension to perform properly, especially in an emergency situation, also worsens. Loss of control and chance of vehicle rollover can be the result of severely worn struts. If a front strut is broken (rather than worn), the vehicle should not be driven until the strut can be replaced.
There is no replacement schedule for front struts, through many vehicles will need to have them changed at some point. Rough driving habits may shorten the life of these parts. Struts may need to be replaced anywhere between 50k and 100k miles. If at any time the struts are leaking, broken, or damaged, they should be replaced immediately. Struts should always be replaced in pairs.
Strut/Shock Absorber Replacement - Front Repair Information
Worn, damaged, or broken front struts are diagnosed in a number of ways. If the vehicle has excessive play in the suspension - if the vehicle bounces easily up and down - the struts are likely worn. Many times, a strut is diagnosed when a technician is replacing other, related parts. A damaged strut may also be discovered during a four wheel alignment.
To change a front strut, a technician first needs to lift and support the vehicle with a hoist (or a jack and jack stands) and remove the front wheel. The brake caliper and rotor are removed and the sway bar link is disconnected. The technician then disconnects the strut from the steering knuckle and from the strut tower to remove it from the vehicle. If the entire strut assembly is being replaced, installation is relatively simple. On the other hand, it is common to reuse the coil spring from the old assembly. In this case, the worn strut will need to be compressed and disassembled, and the new strut will need to be put together before it is installed.
RepairPal recommends replacing the front struts in pairs. The ride quality and performance of the vehicle will be significantly altered if the struts do not match in type and quality. Prior to replacement of the struts, a full inspection of the steering and suspension should be performed to identify any other needed repairs. This will cut down the labor costs when compared to replacing the worn parts separately. Also, we recommend a four-wheel alignment when struts are replaced. The new struts can change the vehicle's ride height, which will change the wheel alignment.
If the front struts are damaged, the wheel alignment of the vehicle will be impaired. During replacement, it may be necessary to compress the old strut. This involves compressing the coil spring so that the strut assembly can be disassembled. From the time that the old strut is disassembled to the time the new strut is assembled, the compressed coil spring is extremely dangerous. If the spring slips from the spring compressor (used to apply tension to the spring), it could cause serious injury. Also, the vehicle needs to be safely lifted and supported off the ground to complete this repair.
Replacing the entire front strut assembly as a unit could be considered an intermediate DIY repair. On the other hand, if the coil spring is to be transferred from the old strut to the new strut, this repair should only be attempted by an advanced DIYer, or left to a professional technician.