I asked most of my friend seem like no one know realy a different with a strut or a shock ???

can some one please explaine ?????

Is a strut is a apart of the shock ??? are they one piece ??

thank........

In short, the primary function of shocks (shock absorbers) is to provide shock damping.

Stuts, in addition to that (and unlike shocks), also provide structural support.

You can read more here:

SHOCKS: http://www.monroe.com/whatshdo.htm

STRUTS: http://www.monroe.com/whatstdo.htm

The previous post is very good.

Shocks and struts provide the same primary function. That is to dampen/control the suspension and vehicle over less than perfect surfaces. In simple terms: keep the car from bouncing when you hit a bump.

Additionally in a vehicle fitted with MacPherson Strut suspensions the damper/strut is also a link in the suspension. If a strut is not in place the wheel/suspension is not able to support the weight of the vehicle and the car doesn't move.

On the other hand a shock is external to the suspension linkage. If you remove the shock the vehicle will still be supported by the wheel. Although you will be bouncing all over the road because the car will oscillate forever (not really but there isn't much damping in the suspension (just a little bit if friction).

A strut does the same job as a shock does. However, the difference is in the way the shock/strut is mounted with the spring.

A shock will either be mounted with its entire length encompassed within a spring, or mounted entirely outside of the spring. On 850's, the rear shocks I believe are entirely encompassed, while on trucks (pick ups), the shocks are mounted to the plate on the leaf springs for example. This is entirely because of the different demands placed on a strut or shock depending on whether it is being used on the front or rear wheels.

With struts, the spring is mounted such that the spring only make up a certain amount of the struts' length. The spring is compressed between the plate on the strut and the vehicle. This leaves the ability to have a continuation of the strut for mounting of various steering and braking components.

Basically, it has to do with the mounting of the strut or shock to the vehicle, wheel and spring. Generally, struts are used on the front wheels, while shocks on the rear. Which is why you'll notice that a shocks wheel mount is a simple both through design, while a strut has a more complicated design incorporating a piece of metal wrapped around the bottom of trhe strut allowing for a different mount to the wheel.

Here's a pic to help clear things up from iPd's site.

The piece on the left is a shock, the other is the strut.

Better double check, but I think this is the right answer.

http://ipdusa.com/images/FrontWheelDrive/bilsteins.jpg