3.3 Chassis

• The functions of a vehicle chassis
• Types of chassis: separate (body-on-frame) and integral (unitary/monocoque)
• Types of frame section used in chassis construction (tube, channel, box, flat)

• describe the types of chassis used on vehicles
• explain the functions of the chassis in a vehicle
• illustrate the types of frame used in the construction of a vehicle chassis
• appreciate the role of the vehicle chassis

“What is the role of the chassis in a vehicle?”

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1. What a chassis is
   40 min · 1 practice tasks · quiz
   The frame that everything mechanical is bolted to, and why it is called the backbone of a vehicle.
2. What the chassis has to do
   40 min · 1 practice tasks · quiz
   Carrying weight, holding alignment, resisting twist and taking the forces of driving - and why twisting is the hard one.
3. Separate chassis: body on frame
   40 min · 1 practice tasks · quiz
   The frame that carries everything with the body simply bolted on top, and why it suits working vehicles and local bodybuilding.
4. Integral construction
   40 min · 1 practice tasks · quiz
   The unitary body where the shell itself does the chassis job, why it is lighter and lower, and why it is harder to repair.
5. Comparing the two constructions
   40 min · 1 practice tasks · quiz
   Weighing separate against integral across weight, cost, repair, body choice and rough-road use, and matching each to the work it suits.
6. Frame sections: tube and channel
   40 min · 1 practice tasks · quiz
   Why a closed tube resists twisting far better than an open channel, and what each section is therefore used for.
7. Frame sections: box and flat
   40 min · 1 practice tasks · quiz
   How a box section is made from a channel, why it must be treated before closing, and where flat bar belongs.
8. Choosing a section for the job
   40 min · 1 practice tasks · quiz
   Two questions that choose a section - what it must resist and what must bolt to it - and what to do when they conflict.
9. The members of a ladder frame
   40 min · 1 practice tasks · quiz
   Side members, cross members and outriggers, why the shape is called a ladder, and why cross members must never be cut carelessly.
10. Inspecting a chassis
    40 min · 1 practice tasks · quiz
    The five faults to look for, where each shows up, and why a bad weld repair can be worse than the crack it covered.