5123190033 Excavator Crankshaft Friction Ring for ISUZU Engine 4BG1

Part number 5123190033 is the original crankshaft friction ring (also known as crankshaft thrust plate) provided by Hitachi Construction Machinery for hydraulic excavators equipped with ISUZU 4BG1 series diesel engines. This component is mainly used to limit the axial movement of the crankshaft and share the frictional load between the crankshaft and the cylinder block. Its universal models cover 12-13 ton small excavators such as Hitachi ZX120 and ZX130, as well as some models such as ZX160 and ZX200 that use 4BG1/4BG1T engines. As an original precision friction pair, its thickness and oil groove design are precisely matched with the crankshaft journal and cylinder seat hole. The use of non-standard auxiliary parts is strictly prohibited to avoid serious faults such as abnormal wear of the crankshaft, excessive axial clearance, and even shaft hugging.

This product is an original bimetallic thrust plate, usually using a steel back+copper lead alloy/aluminum based alloy wear-resistant layer composite structure. Typical technical parameters: standard thickness of 2.0-2.5mm (with repair thickening specifications such as+0.25mm,+0.50mm,+0.75mm), working temperature range of -30 ℃ to+150 ℃, surface hardness of HV180-220, wear-resistant layer thickness of 0.2-0.4mm. The friction surface has oil storage micro pits and oil guide grooves to ensure the formation of a lubricating film; There is a positioning protrusion on the back to prevent rotation during installation. Its friction coefficient is ≤ 0.008, bearing pressure is ≥ 50MPa, and it meets standards such as ISO 3547 and GB/T 1151. It can maintain stability under high speed (≤ 3000rpm) and high impact conditions.

Disassembly inspection: During major repairs or replacement of friction rings, it is necessary to clean the crankshaft journal and cylinder seat hole, and measure the axial clearance of the crankshaft with a dial gauge (standard value 0.10-0.30mm, limit value 0.50mm). Installation points: 1 Confirm the front and back sides of the friction ring (usually with the oil groove facing the direction of crankshaft rotation and the non oil groove facing the cylinder body); 2. Apply an appropriate amount of engine oil on the friction surface (do not use lubricating grease); 3. Install in the original factory order, ensuring that the positioning tongue is inserted into the cylinder slot; 4. Tighten the main bearing cover bolts step by step in a cross sequence (usually with a torque of 120-150N · m). Break in and monitoring: After installation, the metal shavings content in the engine oil should be checked for the first 50 hours of operation; Determine the condition of the friction ring every 500 working hours based on oil pressure and abnormal noise.