C5314775 XCMG GR2605 motor grader main bearing cap

C5314775 (5314775) is a specialized core component designed for Cummins ISB, ISDe, and QSB series engines. As a critical load-bearing element within the engine’s crankshaft support system—also known as the crankshaft main bearing cap—it serves as an essential mating component for the engine block. It is precision-cast as a single piece using high-strength QT500-7 ductile iron and subsequently undergoes aging treatment to relieve internal stresses; for certain specifications, 319S semi-solid aluminum alloy is available as an alternative for lightweight design applications. The component features high rigidity, superior wear resistance, and excellent impact resistance. Its primary functions include securing the main bearings, limiting the crankshaft’s axial displacement, and distributing the dynamic loads generated during crankshaft operation. Furthermore, it positions and supports the crankshaft to ensure stable rotation while providing a mounting datum for the lubrication channels, thereby guaranteeing smooth engine power transmission. Engineered to withstand severe operating conditions—such as heavy-duty loads and high-frequency vibrations—it offers precise installation and reliable load-bearing performance.

Technical Specifications

– Part Number: C5314775 (5314775)
– Brand: Dongfeng Cummins (DCEC)
– Type: Engine Main Bearing Cap (Crankshaft Main Bearing Cap)
– Material: QT500-7 Ductile Iron (Standard Specification); select specifications utilize 319S Semi-Solid Aluminum Alloy (Solution + Aging Treated)
– Compatible Engines: Cummins ISB6.7, ISDe4.5, ISDe6.7, QSB6.7, and B5.9 Series
– Structure: Split-type design featuring an arched structure; includes a main bearing mounting saddle, dowel pin holes, and bolt mounting holes. Select specifications feature reinforcing ribs to optimize structural strength, precisely matching the contour of the engine block’s main bearing saddle.
– Key Dimensions: Length 118mm, Width 85mm, Height 62mm; Inner Diameter of Bearing Saddle: φ76.2mm (matches corresponding crankshaft main bearing dimensions).
– Surface Treatment: Surface phosphating for rust prevention; the inner surface of the bearing saddle is precision-machined and polished to reduce the coefficient of friction.
– Installation Method: Secured to the engine block’s main bearing saddle using high-strength bolts; tightening must follow a cross-pattern sequence and requires alignment via dowel pins for precise centering.
– Alternative Models: 3971018, 5309276, 5311271 (Fully Interchangeable)
– Weight: Cast Iron Version: Approx. 2.8 kg/unit; Aluminum Alloy Version: Approx. 1.59 kg/unit.
– Application Location: Positioned at the engine block’s main bearing saddle; installed in conjunction with the main bearings and crankshaft. Multiple units are installed per engine to function cooperatively.

Application Scenarios

Primarily designed for Cummins series engines installed in Dongfeng commercial vehicles and construction machinery. As a core load-bearing component supporting the crankshaft, it is widely utilized in various heavy-duty and high-vibration operating environments:

– Dongfeng Models: Tianlong, Tianjin, Hercules, Auman, and other medium-to-heavy-duty trucks and buses equipped with ISDe/ISB/QSB series engines.
– – **Construction Machinery:** 18–26 ton wheel loaders, motor graders, bulldozers, excavators (equipped with QSB6.7 and B5.9 engines), forklifts, cranes, and other heavy-duty equipment.
– **Applicable Operating Conditions:** Harsh environments involving long-distance heavy-load transport, mining sites, high-altitude and extreme-cold regions, high-temperature and high-humidity climates, frequent start-stop cycles, and high-frequency vibrations; capable of meeting the high-intensity operational demands of turbocharged engines.
– **Installation Location:** Positioned at the main bearing saddles located at the bottom of the engine cylinder block, corresponding to each of the crankshaft’s main journals; precisely aligned with the cylinder block via locating pins, secured using high-strength bolts, and designed to cover the entire main bearing installation area.
– **Core Functions:** Secures the position of the main bearings; supports the stable rotation of the crankshaft; limits the crankshaft’s axial displacement; distributes dynamic loads generated by crankshaft rotation as well as the explosive pressures from the combustion chambers; provides a mounting reference for lubrication channels; prevents crankshaft run-out and main bearing wear; ensures stable engine power transmission; and extends the service life of both the crankshaft and the main bearings.