Kenworth T400 Hood Fitment Repair and Replacement Challenges

[MikePhua]

The T400 and Kenworth’s Mid-Range Evolution
The Kenworth T400 was introduced in the late 1980s as a versatile Class 7–8 truck designed for regional hauling, vocational work, and urban delivery. Positioned between the T300 and T600, the T400 offered a shorter hood and tighter turning radius while retaining Kenworth’s signature styling and build quality. Its popularity grew among fleets needing a balance of maneuverability and durability, especially in dump, mixer, and tanker configurations.
Kenworth’s modular cab and hood design allowed for multiple engine options, including Cummins and Caterpillar powerplants. However, the hood itself—composed of fiberglass with steel reinforcements—became a point of concern over time due to fitment issues, hinge wear, and damage from repeated opening in harsh environments.
Terminology Annotation:

• Class 7–8 Truck: Heavy-duty commercial vehicles with gross vehicle weight ratings above 26,000 lbs.
  
• Fiberglass Hood: A composite structure used to reduce weight while maintaining rigidity.
  
• Modular Cab: A cab design that allows interchangeability of components across models.
  

Common Hood Fitment Problems
Owners and technicians frequently encounter:

• Hood misalignment with cab fenders or grille
  
• Excessive gap between hood and bumper
  
• Difficulty latching or unlatching due to hinge wear
  
• Hood sagging on one side after years of use
  
• Cracks forming near hinge mounts or latch points
  

These issues often stem from:

• Worn hinge bushings or pins
  
• Frame flex from uneven loading
  
• Previous collision damage or improper repairs
  
• Aging fiberglass losing structural integrity
  

In one fleet operating out of Ohio, several T400s showed consistent hood sag after 10 years of service. Technicians traced the problem to worn lower hinge brackets and fatigued fiberglass around the mounting points. Reinforcing the hinge area with steel plates and replacing bushings restored proper alignment.
Replacement and Retrofit Considerations
Finding a replacement hood for the T400 can be challenging due to limited aftermarket support and model-specific dimensions. While some parts suppliers offer reproduction hoods, compatibility varies depending on:

• Year of manufacture
  
• Engine type and cooling package
  
• Cab-to-hood interface geometry
  
• Grille and headlight configuration
  

Recommendations:

• Measure hood length, hinge spacing, and latch location before ordering
  
• Confirm compatibility with radiator support and air intake routing
  
• Use OEM-style hinges and latches to avoid misfit
  
• Reinforce mounting points with epoxy and steel backing plates during installation
  

In one restoration project in Alberta, a T400 was retrofitted with a modified T800 hood. The installer had to fabricate custom hinge brackets and adjust the grille surround to match the narrower cab profile. The result was functional but required extensive bodywork.
Terminology Annotation:

• Radiator Support: A structural frame that holds the radiator and connects to the hood and grille.
  
• Latch Assembly: The mechanism that secures the hood in the closed position, often spring-loaded.
  
• Epoxy Reinforcement: A method of strengthening fiberglass using resin and embedded mesh or plate.
  

Hinge and Latch Maintenance
To extend hood life and prevent misalignment:

• Lubricate hinge pins monthly with high-temp grease
  
• Inspect latch springs and catches for wear or corrosion
  
• Replace bushings every 2–3 years or when play exceeds 1/8 inch
  
• Avoid slamming the hood shut—use controlled closure
  

In one vocational fleet in Nevada, adding rubber bump stops under the hood corners reduced vibration and prevented cracking near the hinge mounts. The modification cost under $50 per truck and extended hood life by several years.
Aftermarket Solutions and Custom Fabrication
For fleets unable to source OEM hoods, custom fabrication may be necessary. Options include:

• Building a hood from scratch using fiberglass molds
  
• Adapting hoods from similar Kenworth models with modified mounts
  
• Using aluminum or composite panels for lighter weight
  

Fabricators should:

• Reinforce stress points with internal bracing
  
• Match contour lines to cab and fender geometry
  
• Use gelcoat or paint systems compatible with fiberglass
  

In one custom build in Texas, a T400 was fitted with a tilt-forward aluminum hood for easier engine access. The design improved serviceability but required custom air intake routing and grille fabrication.
Conclusion
The Kenworth T400 remains a respected mid-range workhorse, but its hood presents unique challenges as the truck ages. Fitment issues, hinge wear, and limited parts availability demand careful measurement, preventative maintenance, and sometimes creative fabrication. Whether restoring a fleet unit or customizing a vocational rig, attention to hood geometry and mounting integrity ensures the T400 keeps its signature look—and its functionality—on the road. In heavy-duty trucks, the hood is more than a cover—it’s a gateway to performance, service, and identity.