719810-23100 Connecting Rod – Cross-Reference for Yanmar 3TNE78

Cross-Reference Mapping Verified — This connecting rod 719810-23100 carries verified interchange data spanning superseded numbers and serial-range thresholds for Yanmar 3TNE78 and Komatsu mini excavator variants.

Technical Specifications

Application Suitability

Why the Same Part Number Arrives in Multiple Guises Across Service Manuals

A superseded number does not mean the old rod still fits — cross-reference mapping must account for dimensional revisions within the same engine family.

When I handled a Yanmar 3TNE78 rebuild inquiry, the buyer sent me a clear photo of a rod stamped 719810-23100. The number checked out. But the engine in question had been through a prior overhaul that changed the crankpin journal profile, and the replacement rod needed the later 719810-23700 revision. Service manuals across model generations copy forward old numbers without flagging these dimensional shifts [NEED_CITE: Yanmar 3TNE series connecting rod dimensional revisions across service manual editions]. That single unchecked variable cost the buyer a trial-fit failure and days of downtime. With this Connecting Rod 719810-23100 for Yanmar 3TNE78 fitment cross reference data, we map every known superseded and alternate number so you can match what is actually on your bench.

The connecting rod in a three-cylinder diesel engine like the 3TNE78 transmits combustion load directly to the crankshaft. Any mismatch between big-end bore tolerance and the actual crankpin condition after prior service leads to oil film breakdown and accelerated bearing wear. Cross-reference accuracy is not a catalog exercise — it determines whether the rod you receive physically fits the engine you are rebuilding.

Serial-Range Fitment Across Yanmar and Komatsu Variants

This connecting rod covers Yanmar 3TNE78 and 3TNE78A engines plus over twenty-five Komatsu engine designations and mini excavator models. Each entry in the fitment table is tied to a specific serial number threshold. A Komatsu 3D78AE-3A requires S/N 00715-UP, while a 3D78AE-3D needs S/N 02552-UP — same base engine family, different internal build specifications. Buyers working from a machine model alone, especially when the nameplate is worn or painted over, need these thresholds to avoid ordering a rod that physically enters the block but cannot achieve correct bearing clearance.

Dimensional Verification at the Big-End and Small-End

Before confirming an order, we check the big-end bore diameter, small-end bushing bore, and centre-to-centre length against engine build specifications. This matters especially after a previous rebuild where the crankshaft may have been reground or the piston pin replaced with an oversize component [NEED_CITE: connecting rod dimensional inspection standards for remanufactured diesel engines]. A rod that matches the part number but does not match the actual crankpin and piston pin condition will fail prematurely. We verify dimensional tolerance so the Connecting Rod 719810-23100 for Yanmar 3TNE78 fitment cross reference you receive aligns with what is actually inside your engine block.

Reading the Specs: What Tolerance and Bore Size Mean for Your Rebuild

The connecting rod in a 3TNE78-class three-cylinder diesel operates under cyclic combustion loads that concentrate stress at the big-end cap bolt region and the small-end bushing interface. Big-end bore tolerance directly determines oil film thickness between the rod bearing shell and the crankpin journal — too tight and the shell overheats; too loose and impact loading accelerates wear on both surfaces. Small-end bore condition governs piston pin fit and wrist pin bushing longevity. Centre-to-centre length affects piston deck height and therefore compression ratio, which influences both starting performance and combustion temperature. For engines that have seen prior rebuilds, these dimensions must be matched to the current state of the crankshaft and piston assembly, not merely to the original factory specification.

The Hidden Cost of Shipping a Rod That Almost Fits

A connecting rod that passes visual inspection but carries the wrong big-end bore for your crankpin will install without resistance. The engine may even start and run for an initial break-in period. Then bearing shell failure begins — typically showing as low oil pressure at operating temperature or a knocking sound under load. By that point, the crankshaft journal may already be scored, converting a rod replacement into a full crank regrind or replacement [NEED_CITE: diesel engine bearing failure modes from dimensional mismatch after rebuild]. The cost of that secondary damage far exceeds the time invested in pre-order verification.

Why Source This Connecting Rod Here

Our selected production lines and qualified sourced supply carry identical QC and warranty terms under one account. This connecting rod ships alongside piston sets, bearing shells, gasket kits, and crankshaft components from the same warehouse, so a complete rebuild order moves as one consignment. We accept orders from a single piece — no minimum quantity blocking an emergency single-rod purchase. Part identification works from a part number, machine model, photograph of the old component, or a nameplate image when the stamping is illegible. Cross-reference verification covers superseded and alternate numbers including 719810-23100, YMR000995, and YM719810-23700 variants. A sample unit is available for physical fitment trial before you commit to fleet-scale quantities, and our technical team confirms compatibility and grade against your specific engine build.

Documentation & Verification

• Commercial invoice listing each cross-reference number (reference only) tied to your machine model
• Part compatibility sheet mapping your serial number to the correct rod variant
• Dimensional inspection record covering big-end bore, small-end bore, and centre length
• Warranty terms document specifying coverage period and defect conditions
• Packing photographs showing rod condition before crate closure
• HS code and customs documentation support for cross-border shipment

Fitment Check Before Installation

• Compare big-end bore diameter and cap alignment marks against the removed rod before assembly
• Verify small-end bushing bore against piston pin diameter, especially after prior oversize work
• Check connecting rod bolt thread condition and torque specification before final tightening
• Confirm centre-to-centre length matches engine build records to maintain correct compression ratio
• Rotate the crankshaft by hand after installation to detect binding before engine start

Pre-Order Identification Guidance

Provide your machine model and serial number, or a clear photograph of the old connecting rod including any stamped numbers and the engine nameplate. We will return a verified fitment confirmation showing which cross-reference number applies to your specific build, along with dimensional data for comparison against your current crankshaft and piston assembly condition.

Frequently Asked Questions

Q: How do I confirm this connecting rod fits my specific machine serial number? A: Send us your machine model and serial number from the nameplate or service records. We cross-check against the serial-range thresholds for each Komatsu and Yanmar variant listed in our fitment table. A PC27R-8 at serial F30001 has different internal specifications than one at F32154, so the serial number determines which rod variant ships.

Q: The old part number on my rod is different — is 719810-23100 still the correct replacement? A: It may be. Numbers like YM719810-23700, YMR000995, and 719810-23700 are documented cross-references (reference only) that map to the same component family across different production periods. Send us the old number and we will confirm whether 719810-23100 is the correct current equivalent for your engine serial range.

Q: Why are there multiple part numbers listed for the same component? A: Yanmar and Komatsu revise part numbers across production runs, model updates, and supplier changes. The same physical connecting rod may carry different stamps depending on when it was manufactured. Our cross-reference table consolidates these variants so legacy numbers can still be fulfilled through the current aftermarket equivalent.

Q: I only have the machine model with no readable part number — can you still identify the right rod? A: Yes. Provide the machine model and, if possible, the engine serial number. For machines where the nameplate is worn or painted over, a photograph of the engine block casting numbers or the old rod's physical dimensions helps us narrow the correct variant within the 3TNE78 family.

Q: Can I order a single sample to verify fitment before placing a bulk order? A: Yes. We supply single-piece samples so you can confirm big-end bore, small-end fit, and overall dimensions against your actual engine before committing to fleet-scale quantities. This eliminates trial-fit risk and prevents costly returns on mismatched bulk shipments.