- Truck Engines:
- 3406E (S/N: 5EK1-UP; 1MM1-UP; 2WS1-UP; 4AS1-UP; 5DS1-UP; 6TS1-UP; 1LW1-UP)
- C-15 (S/N: EGH1-UP; MBN1-UP; 6NZ1-UP)
- C-16 (S/N: W1A1-UP; 7CZ1-UP)
- C15 (S/N: BXS1-UP)
- C-18 (S/N: MDP1-UP; MEP1-UP)
The valve cover seal and the valve cover fasteners have been redesigned for the truck engines that are listed above. The new 242-9537 Seal is a direct replacement for the previous 172-8027 Seal. The new 243-1159 Fasteners are direct replacements for the previous 173-2390 Fasteners. The new 242-9537 Seal must only be used with the new 243-1159 Fasteners. The previous 172-8027 Seal must only be used with the previous 173-2390 Fasteners. Interchanging the new parts with the old parts will result in an unsatisfactory joint seal. The previous 172-8027 Seal has been cancelled. If the old seal is damaged, or if the old seal is leaking, the seal must be replaced with a new 242-9537 Seal and new 243-1159 Fasteners.
Part Number     | Part Name     | Replacement Part Number     | Replacement Part Name     |
172-8027     | Seal     | 242-9537 and 243-1159     | Seal and Fasteners     |
Note: Six of the new 243-1159 Fasteners are required for replacement.