Crankshaft bearing (upper) – Hahn & Sohn HDE20SS3-DW

Crankshaft main bearings are among the most heavily loaded components in the engine — they support the full weight and dynamic forces of the rotating crankshaft and must maintain a continuous lubricating oil film between the shaft and the engine block. Wear or damage to these bearings is indicated by characteristic engine knocking, a drop in oil pressure and, in extreme cases, can lead to engine seizure.

• This bearing shell is the upper half of one main bearing and is designed for the four-cylinder diesel engine WEICHAI WP2.3D25E200, which is used in the Hahn & Sohn HDE20SS3-DW generator (20 kW / 25 kVA). The bearing features a multi-layer construction (steel backing with bearing alloy on the inner surface), an oil hole for the passage of oil from the crankshaft and a locating tab, which ensures correct positioning and prevents the bearing shell from rotating in its housing.
• When replacing the main bearings, it is essential to replace the complete set (upper and lower shells at all positions), not just an individual piece — uneven wear between old and new bearings would lead to uneven loading of the crankshaft.

WHY CUSTOMERS CHOOSE IT

• Exact match for the WEICHAI WP2.3D25E200 engine — part designed for the specific crankshaft bearing position
• Multi-layer construction — more resistant to wear than a single-layer design
• Essential part for a complete engine overhaul — without high-quality bearings, there is a risk of repeated failure or engine seizure

PRACTICAL TIP

Before installing new bearing shells, always check the condition and dimensions of the crankshaft journals using a micrometer — if the journals are worn or scratched beyond tolerance, the crankshaft must be reground and corresponding undersize bearing shells used; otherwise the new bearings will quickly wear out.

 KEY FEATURES

• Type: upper crankshaft main bearing shell
• Design: multi-layer construction (steel backing + bearing alloy)
• Designed for engine: WEICHAI WP2.3D25E200
• Compatible generator: Hahn & Sohn HDE20SS3-DW (20 kW / 25 kVA)
• Oil hole for lubricant passage
• Locating tab to prevent rotation

USE / INSTALLATION / OPERATION

1. Before starting work, disconnect the generator from the power supply and drain the engine oil and coolant.
2. Remove the oil sump and remove the crankshaft main bearing caps.
3. Remove the crankshaft and the old bearing shells (upper and lower).
4. Before installing the new shells, inspect and measure the crankshaft journals.
5. Fit the new upper shell into the engine block so that the locating tab engages in the corresponding groove; the oil hole must align with the oil passage.
6. Proceed in the same way with the lower shell and bearing cap, then tighten to the specified torque.
7. Before starting the engine, refill the oil and check that the crankshaft rotates freely.

Installation of the main bearings requires experience with combustion engine servicing and precise measuring instruments — we do not recommend replacing them yourself without specialist knowledge.