Subframe and Mounting Systems

Subframe and Mounting Systems


Front Subframe

The front subframe is bolted to the body and is used to:

- aid in structural support.
- provide mounting surfaces for the front suspension control arms.
- provide a mounting point for the engine isolators.
- provide the mounting surface for the steering gear.
- provide the mounting surface for the sway bar.


Rear Subframe

The rear subframe is bolted to the body and is used to:

- aid in structural support.
- provide mounting surfaces for the rear suspension control arms.
- provide mounting surfaces for the rear differential All-Wheel Drive (AWD).


Welding Precautions

The correct equipment and settings must be used when welding mild or high strength steel. Metal Inert Gas (MIG) and resistance spot welding are the preferred methods. Surfaces must be clean and free of foreign materials.

- Do not weld on the subframe.
- The correct protective clothing should always be worn.
- Adequate ventilation must be provided to avoid accumulation of poisonous gases.
- A test weld should always be carried out on a test sample.
- Follow equipment manufacturer's prescribed procedures and equipment settings for the type of weld being used.
- Disconnect the battery ground cable from the battery.
- On Hybrid vehicles, depower the high voltage traction battery system.
- Disconnect on-vehicle modules and protect them from possible heat damage and electrical currents when welding.
- Corrosion protection needs to be restored whenever it is necessary to sand or grind through painted surfaces or E-coat, or when bare metal repairs are carried out. Refer to Restoring Corrosion Protection Following Repair.

Underbody misalignment can affect front and rear wheel alignment, the operation of the suspension parts and drivetrain operation. Window glass cracks, door and window opening concerns, and air or water leaks at the doors are often caused by incorrectly tightened bolts and body misalignment.