A. Frame Preparation Flashcards
VERIFY THE DEFINITION OF WHEELBASE
The distance between the center of the front axle and the center of the rear axle. For trucks with more than two axles, the wheelbase is the distance from the steering axle to the center of the driving axle group. Wheelbase affects truck performance, body installation, and whether an axle is overloaded.
VERIFY CAB-TO-AXLE
The distance from the back of the cab to the center of the rear axle. For tandem-axle trucks, the CA is the distance from the back of the cab to the center of the tandem. CA helps determine the length of the body that can be mounted on the chassis.
Verify Cab -To-Trunnion
The distance from the back of the cab to the center of the tandem. CT is a similar concept to CA, but is used for tandem-axle trucks.
What is gross vehicle weight rating (GVWR)
GVWR is the maximum weight a vehicle can safely carry when fully loaded, including passengers and cargo
Verify gross vehicle weight rating (GVWR)
You can verify a vehicle’s gross vehicle weight rating (GVWR) in a few ways:
-Check the owner’s manual: The GVWR is often included in the vehicle’s owner manual.
-Check the trailer: For trailers, the GVWR are usually located on a vehicle placard on the left side. The placard also provides information about tire and loading.
What is gross axle weight rating (GAWR)
-GAWR is the maximum weight that each axle can support.
-The GAWR specifies the maximum weight that each axle can support.
Tool a technician uses to Verify frame width, height, and length of a vehicle.
Measuring the length, width, and height of a car can be done using the following steps:
Tools Needed
Measuring tape
Level surface (for accurate measurements)
Notepad and pen (optional, for recording measurements)
Describe the steps used to verify Frame Length
Frame length is also found in the body builders manual, and it can be measured on the truck.
Describe the step used to verify frame width.
While the generally accepted standard frame width in the United States and Canada is 34 inches that is NOT ALWAYS THE CASE on the truck a technician might be working on. Many imported chassis do not comply with the 34 inch generally accepted principle. Is is important therefore to check the dimensions on the truck and on the body builder’s manual.
Describe the step used to verify frame height.
Frame height is more difficult because the technician just allow for spring deflection. Original equipment truck chassis manufacturers use various recommended practices for calculating chassis height under specific loads. This is also found on the body builders manual of other OEM publications.
How do you determine truck body/equipment layout locations.
Relocate and/or modify frame-mounted truck components/systems as necessary.
Relocating or modifying frame-mounted truck components requires careful consideration to maintain structural integrity and compliance with regulations. Key steps include:
Frame Modifications: Ensure any frame length changes maintain the original resistance bending moment (RBM) by reinforcing appropriately.
Component Relocation: Use existing brackets and mount components inside frame flanges to avoid compromising structural integrity.
Regulatory Compliance: Obtain approval from the engine manufacturer for emissions-related modifications to ensure compliance with noise and emissions standards.
Crossmembers and Reinforcements: Strategically place crossmembers to support loads and prevent frame twisting
Repair, lengthen, shorten or reinforce truck frame and frame members.
When modifying a truck frame, several methods can be used depending on whether you are shortening, lengthening, or reinforcing it.
Shortening:
Cut and Weld: Cut a section out and weld the frame back together. This is a common but not always the best method.
Slide Tandems: For some trucks, sliding the tandem axles forward without cutting can be effective.
Lengthening:
Weld and Fish Plate: Extend the frame by welding in new sections and using fish plates for reinforcement.
Use Frame Rails: Use actual frame rails as fillers instead of plain channels for better flexibility and strength.
Reinforcing:
Boxing the Frame: Adding a box section to the frame can increase strength and reduce stress on welds.
Gusseting: Use gussets to reinforce joints, especially where cuts are made.
Always ensure high-quality welds and proper alignment to maintain structural integrity.
Lay out mounting holes on a truck; select appropriate tools.
To lay out mounting holes on a truck and select appropriate tools, follow these steps:
Choose the Right Mounting Kit: Select a mounting kit designed for your truck’s make and model to ensure a proper fit.
Gather Tools: You’ll need a high-quality drill with appropriate drill bits, a measuring tape for precision, and a pencil for marking.
Prepare the Truck Bed: Clean the area where the toolbox will be installed. Use the measuring tape and pencil to mark where holes will be drilled.
Drill Holes: Carefully drill holes at the marked spots using the appropriate drill bit size.
Install Mounting Brackets: Securely attach the mounting brackets with screws provided in the kit.
Attach Toolbox: Align and secure the toolbox onto the brackets using screws, ensuring it is level and properly aligned.
Prepare truck if welding.
When preparing to weld on a vehicle, you can take these steps:
-Disconnect the battery
Check your car’s owner’s manual to see if you need to disconnect the battery before welding. If you do, make sure all systems are also shut down
-Remove electronics
Remove any batteries, sensors, wires, and other electronic components from the welding area.
-Avoid burning surfaces
Be careful not to burn painted surfaces, glass, moldings, and interior.
-Avoid welding near sealants
Noise, vibration, and harshness (NVH) sealants and other types of foams and sealers are highly flammable.
-Avoid welding near electrical systems
Don’t route welder electrical cables directly across or near any of the vehicle’s electrical wiring harnesses.
-Prepare the metal
Use a wire brush, cloth and solvent, sanding discs, sheets, or belts, or an angle or die grinder to remove surface impurities or defects.
-Wear protective gear
Wear leather welding gloves and welding-specific sleeves, jackets, or aprons.
Inspect truck frame and frame members for damage (such as: cracks, breaks, distortion,
elongated holes, looseness, and corrosion); determine needed repairs.
Visual Inspection: Look for visible signs of damage such as cracks, breaks, distortion, elongated holes, or corrosion. Check for unusual gaps or misalignment in panels and doors.
Advanced Diagnostic Tools: Use ultrasonic testing to detect internal flaws and magnetic particle inspection to reveal surface defects.
Load Capacity and Stress Points: Analyze the frame’s load-bearing capabilities and inspect stress points like suspension mounts and cross-members for any signs of weakening or damage.
Documentation: Take detailed notes and photographs of any damage to support repair estimates and insurance claims
Tool a technician uses to Verify frame width, height, and length of a vehicle.
Measuring the length, width, and height of a car can be done using the following steps:
Tools Needed
Measuring tape or laser distance measurer
Level surface (for accurate measurements)
Notepad and pen (optional, for recording measurements)
