CAT 503-9731 Engine Front Housing Shroud

Part Number CAT 503-9731 (5039731) Engine Front Housing Shroud

Material: Glass fiber reinforced nylon PA66-GF30 (30% glass fiber), with an oil-resistant and UV-resistant coating; mounting flange/clip is modified PA66, gasket is EPDM EPDM rubber

Typical Compatible Models: Primarily compatible with heavy industrial/marine engines such as C15 ACERT, C18, and 3512C; common complete engines: Caterpillar 793F mining truck, 3512C marine main and auxiliary engines, G3516C gas generator set

Structure Type: Annular air intake shroud with flange bolt mounting, built-in EPDM sealing groove, pre-drilled pulley/crankshaft front end shaft extension hole, with ventilation guide vanes

Key Dimensions (Nominal): Flange outer diameter 285mm, shroud overall height 86mm, center shaft hole diameter 62mm, bolt hole distribution circle diameter 240mm diameter, 8 M10 mounting holes, evenly spaced; sealing groove width 5mm, depth 2mm.
Operating Environment: Temperature resistance -40℃ to 125℃, oil resistance (diesel/engine oil/ethylene glycol), protection rating IP54, vibration resistance (10-500Hz).
Weight: Approximately 1.9 kg (excluding bolts and sealant).
Installation Torque: M10 flange bolts, recommended 28-32 N·m, requires anti-loosening gasket, and application of CAT-specified oil-resistant sealant (e.g., 2C-9616).
III. Applicable Scenarios and Matching Relationships
Installation Position: Directly fastened to the flange face of the engine front housing, located outside the crankshaft pulley, with the inner side fitting against the front oil seal seat, and the outer side covering the pulley assembly.
Matching Parts: Commonly used with 383-0423 front housing flange gasket, 127-0712 M10 anti-loosening bolts, and 2C-9616. Use with compatible sealant; when replacing, simultaneously check the front oil seal (e.g., 127-5115) for leaks; Operating condition recommendations: For high dust/high humidity environments such as mining, ports, and offshore platforms, it is recommended to check the protective cover for cracks, loose clips, and aging gaskets every 2000 hours.

IV. Installation and Maintenance Points

Installation Steps
**Thoroughly clean the front flange face and the cover mounting surface, removing old sealant, oil, and rust.**
**Evenly apply 2C-9616 sealant to the cover’s sealing groove and install the EPDM gasket.**
**Align the bolt holes and hand-tighten all M10 bolts, alternating steps with a torque of 28-32 N·m.**
**Check that there is no interference between the cover and the pulley, and that there is no abnormal friction noise when rotating the crankshaft.**

Replacement Criteria: The cover must be replaced if it shows cracks (especially at the flange root), broken clips, deformed sealing surfaces, or coating peeling leading to substrate corrosion. It is strictly forbidden to repair with AB glue or similar materials and continue using it in high-vibration conditions.**

Maintenance Cycle: Check every 2500 hours under standard operating conditions; shorten to 1200 hours under harsh operating conditions (high temperature, high dust, salt mist).