Frame: Description and Operation
FRAME AND BODY MOUNTINGThe frame consists of 2 steel channel rails, a front crossmember, transmission support crossmember and a rear crossmember (trailer hitch). The side rails and welded crossmembers are not replaced separately. A front frame rail repair kit (5D058 and 5D059) is available if the front rail is to be repaired.
Magnesium Alloy Radiator Support
The radiator support is a magnesium die casting with steel bridging brackets bolted to the casting. It replaces the traditional welded-on steel design. The radiator support assembly is welded into the inner fenders and shotgun, via the bridging brackets, just as the traditional weld-on steel radiator supports do. Aluminum spacers between the magnesium radiator support and steel components are required to prevent galvanic corrosion. Minor straightening can be done to the casting as long as no cracking occurs during straightening.
Care should be taken to avoid overheating and creating a fire when using oxyacetylene equipment or plasma arc cutting equipment around this or any other magnesium part, for example to remove severely damaged parts. A magnesium casting is extremely unlikely to catch fire, due to its ability to dissipate heat quickly and high temperature necessary to affect the casting. However, if the entire mass of the casting reaches the melting point of magnesium of approximately 427°C (800°F), there is the potential for a fire. Normally, localized heat applied to magnesium casting will simply burn a hole through the casting with no fire risk. In the unlikely event that the entire mass of a magnesium casting does reach 427°C (800°F) and results in a fire, a class D fire extinguisher should be used. Class A, B or C fire extinguishers can spread the burning material without extinguishing it. Water will cause the fire to burn faster.
Body Support Mounts
Body Support - Front End Sheet Metal Body Mount:
Body Support - No. 1:
Body Support - No. 2 (Regular Cab, SuperCab And SuperCrew) And No. 3 (RH, SuperCab And SuperCrew):
Body Support - No. 2 (RH, Regular Cab):
Body Support - No. 3 (LH, SuperCab And SuperCrew):
The body support mounts:
- secure the body to the frame.
- cannot reuse body support mounting fasteners. New fasteners must be installed for each fastener that has been removed or loosened.
- cannot be lubricated during body support mount installation.
- on SuperCrew and SuperCab, share a common fastener with the rear seat. Do not drive the vehicle with the rear seat removed unless the rear seat fasteners are installed.