What is the left support plate of the car's lower passage?
There is no unified standard name for the "left support plate of the low passage". It usually refers to the plate-shaped part at the left bottom of the vehicle body that is used to support or connect the "low passage" structure. It is not the side skirt plate that can be seen on the outside of the vehicle door.
You can think of it as several types of things, depending on the specific location:
Central passage/low passage reinforcement piece: The supporting or reinforcing plates on both sides of the longitudinal groove in the center of the vehicle floor (the passage for exhaust pipes and transmission shaft routing), which are used to enhance the rigidity of the vehicle body and help transfer energy during a collision, protecting the battery and passengers.
Chassis support point/support block: The special support positions on both sides of the chassis near the wheels, used to support the jack, often located inside the side skirt, not ordinary steel plates, capable of withstanding large pressure.
Components related to the lower suspension arm: The lower arm (lower arm) and ball joint, rubber sleeves, etc. of the chassis suspension, connecting the rocker arm and the frame, affecting the wheel alignment and driving stability.
The most confusing part is: The strip under the vehicle door is the "side skirt plate", which belongs to the exterior aerodynamic component and is not the same as the "low passage support plate".
If you see this name on a repair list or parts list, it is recommended to directly ask the repair technician exactly which part it refers to, as the naming conventions vary greatly among different vehicle models.
The main function of the "left support plate of the low passage" is to strengthen the vehicle structure, increase rigidity, and help distribute the impact force during a collision.
It is a type of vehicle body reinforcement plate, connecting and supporting to make the vehicle body more integrated and reduce local deformation. Specifically:
Enhance rigidity: Provide additional support in the low passage (the floor passage in the middle of the vehicle body) to enhance the torsional and bending strength of the vehicle body.
Collision protection: During a collision, it can absorb and distribute part of the impact force, protecting the passenger compartment space.
It is necessary to distinguish: The protruding "small iron plate" under the vehicle door is called "chassis support block", which is a support point for the jack during tire replacement or repair, not the low passage support plate, and their functions are different.
The "left support plate of the low passage" is a relatively professional term. Currently, there are no complete fault cases corresponding to this name in public materials. Considering the vehicle structure, it is likely that what you are referring to is the support plate in the left part of the chassis or vehicle body passage, such as the lower support plate of the middle passage or the chassis guard plate. The common manifestations and handling ideas for such plate failures are as follows:
Common failure manifestations
Abnormal noise: Metal "clattering" or "clicking" sound, mostly due to loose fixed screws; low-speed "buzzing" resonance sound, mostly caused by excessive adhesion between the plate and the chassis resulting in resonance.
Plate deformation or damage: Mostly due to bottoming out, impact, or long-term bearing excessive weight, causing the support plate to deform, affecting the structural stability.
Connection loosening: Screws not tightened or loosening after long-term vibration, causing a shaking sensation during driving, and even可能导致 component separation.
Troubleshooting and handling suggestions
First, determine the source of the sound： After parking and turning off the engine, shake the edge of the plate with your hand, feeling any looseness or hearing metal contact sounds, it is usually due to loose screws; or you can use a rubber hammer to lightly tap various parts, the location of the sound is the loose point.
Screw loosening type： Use a lift or trench to tighten all screws of the guard plate in a diagonal sequence, torque 15-25 Newton-meters; if the screws still loosen after multiple tightening attempts, apply blue thread lock adhesive or add a spring washer, the cost is a few dollars.
Plate deformation or damage： If it has obviously deformed or cracked, do not forcibly knock it back, it is recommended to directly replace the new part; the support plate is a structural component, its deformation will affect its strength.
If unsure, go to a professional store： If the abnormal noise persists after troubleshooting or if it involves hydraulic, braking, etc. related systems, it is recommended to conduct a chassis system check at a 4S store or a regular repair shop, do not blindly replace parts.
If the abnormal noise is accompanied by the metallic impact sound when passing over the bump and a sense of looseness in the chassis， it may not just be the support plate itself. It could also involve the rubber sleeves of the lower tie rod， the bushings of the balance rod， or the aging of the shock absorber top rubber. It would be best to have a professional check the chassis rubber sleeves， the ball joints， and the shock absorbers together.
If you want to know more, keep reading the other articles on this site!
Please call us if you need such products.
Zhuo Meng Shanghai Auto Co., Ltd. is committed to selling MG&MAXUS auto parts welcome to buy.
