Exam 32: Vehicle Chassis Frame

Technician A says that two truck frame rails with exactly equal RBMs,can have very different dynamic performance.Technician B says that highway tractors are required to have much higher section modulus (SM)than dump trucks.Who is correct?

Technician A says that in some tanker trailer applications,the tank can be used as the primary frame,with sub-frames attached to the tank to mount the upper coupler and suspension components.Technician B says that a tank mounted to a straight truck with a ladder frame must be mounted in a way so that the frame moves independently from the tank.Who is correct?

When carrying very heavy loads is the primary consideration in choosing a highway tractor frame,which of the following would be the best choice?

What is the function of the crossmembers that unite a pair of rails in a truck suspension?

Technician A says that the center of a dump truck frame at the lift ram mounting point is subject to the most stress when the dump box is fully raised.Technician B says that the front and rear of a highway tractor frame is subject to less stress than the remainder of the frame.Who is correct?

Where is the neutral fiber of a C-channel frame rail located?

What is the term used to describe a frame bolt that is designed with an interference-fit shank?

Which of the following truck frame materials has the highest yield strength?

A suspension mount bolt hole has become enlarged in a frame due to shear forces.What should be done?

When diagnosing suspected frame misalignment,which of the following should be performed before projecting the frame measurements to the floor?

When selecting a welding method and filler wire or electrode to repair a cracked frame rail,which of the following must be considered?

Technician A says that a low section modulus frame (SM)has the advantage of better ride,a desirable feature in highway tractors.Technician B says that keeping SM low and rail yield strength high,is one way of achieving a highway tractor frame that has a forgiving ride and high RBM.Who is correct?

When a fully loaded dump box is raised on a dump truck,which section of the frame is subject to the most stress during the process?

On a ladder type highway tractor frame,what components are referred to as the rails?

When you have to cut tempered frame rails to extend a frame,which of the following angles would be recommended?

Technician A says that the a three-element frame rail can usually achieve a high section modulus (SM)without adding additional weight.Technician B says that one way of meeting a high RBM requirement and keeping the weight of a frame to a minimum is to use hardened steel frame rails.Who is correct?

Technician A says that diamond frame damage is often caused when a ditched truck,is hauled out by attaching chains to just one side of the frame.Technician B says that twist frame damage can be caused by using a truck as a snowplow.Who is correct?

Technician A says that when extending a tempered frame rail,the extension channel does not have to be tempered so long it is at the rear of the truck.Technician B says that when extending a tempered frame rail,either a 45- or 60-degree cut-angle is recommended to avoid a sudden change in RBM over a given vertical section.Who is correct?

Which of the following on a highway tractor I- or C-channel frame rail is vertical?

Technician A says that low hydrogen arc welding electrodes should be used when it is necessary to weld on a hardened steel frame rail.Technician B says that tempered steel rails can be MIG welded using appropriately rated wire in less time and lower risk of comebacks.Who is correct?