Engine Serial Variants Confirmed — crankshaft journals measured against V1505 build variant to determine correct bearing grade and thrust washer thickness before dispatch.
Technical Specifications
| Parameter |
Value |
| Part Number |
1G871-23012 |
| Product Type |
Crankshaft |
| Cross-Reference |
1G871-23013, 1G87123012, 1G87123013 (reference only) |
| Machine Fitment |
KX71, KX71-3 CABIN, KX71-3 CANOPY, KX71-3S CABIN, KX71-3S CANOPY, KX91-2, F3560, F3680, F3680-AU |
| Engine Fitment |
Kubota V1505 |
| Material |
Forged 42CrMo alloy steel |
| Journal Hardness |
52–56 HRC (induction-hardened) |
| Runout Tolerance |
≤0.03 mm |
| Surface Finish |
Ra ≤0.8 μm |
| Inspection Method |
Magnetic particle inspection (MPI) |
| Condition |
New Aftermarket |
| Warranty |
6 months against manufacturing defects |
Application Suitability
| Engine System |
Related Components |
| Bottom-end rotating assembly |
Main bearings, con rod bearings, thrust washers |
| Lubrication and sealing |
Front and rear main seals, oil pump drive gear |
| Overhaul kit composition |
Piston sets, cylinder liners, full gasket set |
| Emission and auxiliary |
Torsional damper, crankshaft position sensor ring |
Why the Wrong Bearing Grade Guarantees a Second Teardown
A crankshaft swap that ignores bearing clearance history, previous regrind work, and thrust washer selection almost always ends with the engine back on the bench before the next scheduled service. Matching a crankshaft for Kubota V1505 engine overhaul to the correct oversize or standard grade is not optional — it is the single step that determines whether the rebuild survives its first hundred hours [NEED_CITE: engine bearing clearance standards for small displacement diesel engines].
I spent years on Central Asian job sites watching excavators return with spun bearings because someone fitted standard shells onto journals that had already been ground undersize during a previous rebuild. The Kubota V1505 is no exception to this pattern. Different engine serial variants within the V1505 family carry subtle differences in thrust washer dimension and seal diameter, and overlooking these details during a crankshaft for Kubota V1505 engine overhaul means the failure mode simply repeats.

The System Around the Crankshaft
This crankshaft sits at the center of the V1505 bottom-end assembly, and every component that touches it must be matched as a set. Main bearing shells, connecting rod bearings, thrust washers, and the front and rear main seals all share the same wear history. Replacing only the crankshaft for Kubota V1505 engine overhaul while reusing old bearings or seals transfers the previous failure mode directly into the new assembly.
Serial Variants and Rebuild History
Different production runs of the V1505 use distinct thrust washer thicknesses and, in some variants, different front seal diameters. When a crankshaft has been reground in the past, journal diameter shifts to an undersize category and standard-grade bearings will leave excessive clearance, causing oil pressure loss and accelerated wear. Confirming engine serial number and measuring existing journals before ordering ensures the correct crankshaft for Kubota V1505 engine overhaul arrives with matched bearing shells and seals [NEED_CITE: Kubota V1505 serial variant identification procedures].
What the Numbers Actually Mean
The 42CrMo forged alloy provides a balanced combination of core toughness and surface hardness after induction hardening. The 52–56 HRC journal range resizes well during future regrinds without risking case-depth breakthrough. Runout held within 0.03 mm prevents uneven bearing load distribution across main journals, which is where out-of-round crankshafts typically initiate fatigue cracks. A surface finish of Ra 0.8 μm or finer on the journal faces supports stable hydrodynamic oil film formation at normal operating RPM, reducing boundary-contact wear during cold starts.

The Cost of Skipping Root Cause Analysis
Fitting a new crankshaft without diagnosing why the original failed — oil starvation from a blocked pickup screen, diluted lubricant from fuel system leakage, or a degraded torsional damper allowing destructive harmonic vibration — simply resets the clock on the same failure. The second teardown usually involves scored cylinder walls and damaged connecting rods, not just bearing replacement. Shops that skip the root-cause step absorb the labor cost twice and lose customer confidence in the process [NEED_CITE: diesel engine crankshaft failure root cause analysis methodology].
Why Source This Assembly Through XUNPO
Both our in-house production lines and qualified sourced partners operate under the same quality control and warranty terms, so a crankshaft and its matched bearing set carry identical coverage under one account. Eight product categories mean the overhaul kit — pistons, liners, gaskets, seals, and this crankshaft — ships as a single consignment from the Guangzhou warehouse. One-piece minimum order allows emergency single-engine repairs without waiting to aggregate quantities. Part identification works from a part number, a machine model plate, or a photograph of the worn component. Cross-reference verification covers superseded and alternate numbers, and sample supply is available for fitment confirmation before any bulk commitment.
Documentation & Verification
- Commercial invoice listing crankshaft and all matched bearing grades
- Compatibility and cross-reference sheet marked reference only for OEM numbers
- Dimensional inspection record including journal diameter and runout readings
- MPI certification confirming absence of subsurface cracks
- Packing photographs taken before carton closure
- HS code and customs documentation for engine component export
Installation & Rebuild Sequence
- Clean all oil galleries with solvent and verify passage flow before assembly
- Measure each journal with a micrometer to confirm standard or oversize grade
- Install thrust washers at the designated main bearing cap, checking endplay with a dial indicator
- Torque main bearing caps in the specified sequence to the V1505 manual values
- Prime the lubrication system and verify oil pressure at cranking speed before first start
- Run the engine under light load for the initial break-in period per rebuild protocol
Request a Matched Overhaul Quotation
Send the engine model, serial number, and any previous rebuild records so we can confirm journal condition, bearing grade, and seal dimensions. If the nameplate is unreadable, a photograph of the old crankshaft stamping or the engine block casting number is sufficient for identification. We will return a complete overhaul kit list with every line item matched to your specific V1505 build variant.
Frequently Asked Questions
Q: What bearing grades and seal kit do I need with this crankshaft for my V1505 engine serial?
A: Bearing grade depends on journal condition — standard if journals are within factory tolerance, or oversize if previously reground. Seal dimensions vary across V1505 serial variants. Provide the engine serial number or a photo of the existing components, and we will confirm the correct matched set before shipping.
Q: My crankshaft journals have been ground before — how do I determine the correct oversize grade?
A: Measure each main and rod journal with a micrometer and compare against standard and oversize tables. If journals were ground to 0.25 mm undersize, you need 0.25 oversize bearing shells. We can review your measurements and supply the matching crankshaft or confirm whether a further regrind is viable.
Q: Do different V1505 engine serial variants use different internal components?
A: Yes. Thrust washer thickness, front main seal diameter, and in some cases oil pump drive gear configuration differ across V1505 production runs. Identifying the exact engine serial variant ensures every component in the overhaul kit fits without modification or substitution during assembly.
Q: What typically causes crankshaft failure on Kubota V1505 engines, and how do I prevent repeat failure?
A: Common causes include oil starvation from blocked pickup screens, contaminated lubricant, and torsional damper degradation allowing harmonic stress. Addressing the root cause — not just replacing the failed component — prevents the new crankshaft from repeating the same failure cycle within a short operating period.
Q: Can I get a complete overhaul kit including this crankshaft, bearings, pistons, and gasket set in one shipment?
A: Yes. We consolidate crankshaft, matched bearings, piston assemblies, cylinder liners, full gasket set, and seal kit into a single consignment. Every line item is verified against your engine serial variant, so the complete V1505 rebuild arrives ready for assembly without missing components.