My business is auto body repair Salt Lake City. Last week a customer brought in a car that was making an odd noise when he drove it. I put the car up on the lift and saw that the lower rail on his unibody constructed vehicle was cracked at the lower control arm and the crossmember mount. Of course I knew that in order to repair the vehicle I had to replace the lower unibody rail. I understand that to a non-Greek speaking person who is unfamiliar with a mechanic’s jargon this probably sounds like Greek to them. I will attempt to clarify what I mean.
In 2016, a vehicle typically has one of two basic types of structure; frame and unibody. A frame structure is comprised of different pieces which connect at different locations. Upon this frame is mounted the suspension, axels and the engine. On top of all this is mounted the actual body of the car. By contrast, a unibody type structure does not employ a separate frame from the vehicle’s body. Unibody structures are typically constructed from aluminum or steel which is then stamped with cross members upon which the other components are mounted. Most vehicles these days are constructed using a unibody structure. The two main advantages of unibody construction is that it keeps the vehicle’s over all weight lower compared to frame structure and it also redirects the force of a crash away from the passengers inside the car.
As I said, my business is auto body Salt Lake City and I know cars. When you are my customer there is no need for you to know the difference between unibody and frame construction. That is my job. That is how I knew that to repair the vehicle I had to replace the lower unibody rail.