K03 Turbocharger 7256748 for Doosan D34 – Verified Fitment

Verified Fitment Variant — Every K03 turbocharger 7256748 is checked against your specific Doosan D34 serial prefix and Bobcat model year before dispatch.

Technical Specifications

Application Suitability

Why the Same K03 Turbocharger Number Ships in Several Variants

The base number alone does not guarantee the right unit reaches your machine.

A single K03 turbocharger 7256748 designation covers multiple production runs spanning different Bobcat and Doosan model years. Each variant can differ in exhaust outlet angle, oil drain flange geometry, and actuator mounting position. I have seen units arrive on site where the outer diameter matched perfectly, yet the exhaust port sat a few degrees off the downpipe mating surface — close enough to bolt on, wrong enough to leak under boost. Cross-reference tables copied between sellers often carry these variant errors forward, leaving the buyer to discover the mismatch only after the machine is partially reassembled [NEED_CITE: turbocharger variant identification standards for compact diesel engines].

Fitment Range and Serial-Level Verification

Confirming the correct K03 turbocharger for Doosan D34 applications starts with the engine serial prefix. Doosan D34 engines installed across the Bobcat S740 through T870 range were built in several configurations, each with subtle differences in turbo mounting and plumbing. A unit that fits an S750 may not align correctly on a T870 despite sharing the same base engine family. Providing the serial prefix allows us to narrow the variant down before anything ships.

Interface Checkpoints That Separate a Fit From a Fail

The critical physical interfaces on this turbocharger include the oil inlet and return flanges, the exhaust outlet orientation, and the compressor housing inlet diameter. Oil return flange bolt patterns shifted between early and late D34 builds, meaning an incorrect variant will leave one or more bolt holes misaligned. Exhaust outlet angle determines whether the existing downpipe connects without modification. Compressor inlet diameter must match the charge air hose ID to prevent boost leaks. Each of these is checked against your specific machine model and build configuration before dispatch [NEED_CITE: turbocharger oil drain flange bolt pattern variations across compact diesel platforms].

Reading the Specs That Actually Matter

The 74–100 HP engine output range indicates this K03 turbocharger covers both standard and high-output D34 calibrations. The turbine housing A/R ratio governs how quickly the turbo spools at low RPM versus how much top-end flow it supports — a mismatch here means either sluggish response or excessive backpressure. Wastegate actuator calibration must match the engine's boost target; an incorrectly calibrated actuator causes either chronic underboost or dangerous overboost conditions. These parameters are verified against the engine code on your machine's data plate.

The Hidden Cost of a Near-Miss Fitment

A turbocharger that bolts on but does not align precisely at every interface creates problems that surface only after the machine returns to work. A slight exhaust port offset produces a leak that erodes the gasket and flange over time, eventually requiring a second teardown. An oil drain restriction from a misaligned flange pushes oil past the turbo seals, contaminating the intake and fouling the DPF. These failures are often misdiagnosed as turbo defects rather than fitment errors, leading to unnecessary warranty claims and continued downtime [NEED_CITE: root cause analysis of premature turbocharger failure in compact equipment].

What This Part Requires From Your Side

Our approach to the K03 turbocharger 7256748 centers on elimination of guesswork. Cross-reference verification covers superseded numbers across the 150105-00344 series and 5303-970/988 series to confirm which variant your machine actually needs. Identification from a worn nameplate photograph or machine model alone is routine here. Sample units ship for bench fitment confirmation before any bulk commitment, so you can verify port positions and flange patterns on your own bench. Technical review of your engine serial prefix narrows the exact build configuration. All self-produced and sourced supply carries the same warranty terms under one account.

Documentation & Verification

• Commercial invoice listing each cross-reference number matched to your machine model
• Fitment sheet showing oil flange bolt pattern and exhaust port angle for your serial range
• Dimensional inspection record covering compressor inlet diameter and turbine housing A/R
• Warranty terms covering manufacturing defects for 3–12 months
• Packing photographs showing protective caps on oil and air ports before crating
• HS code and customs paperwork prepared for turbocharger export classification

Fitment Check Before Installation

• Compare oil return flange bolt hole spacing against the removed unit before mounting
• Verify exhaust outlet angle matches the downpipe mating flange without forcing alignment
• Confirm compressor inlet diameter accepts your existing charge air hose clamp range
• Pre-lube the turbo bearing housing with clean engine oil before first cranking
• Check wastegate actuator rod travel matches the specification for your D34 engine code
• Run the engine at idle for several minutes to verify oil flow before applying load

Send Us the Details That Confirm a Match

Provide your Bobcat or Doosan machine model, the engine serial prefix from the D34 data plate, and a photograph of the existing turbocharger nameplate if readable. If the nameplate is worn or painted over, a clear shot of the oil return flange and exhaust outlet helps narrow the variant. For fleet orders, a list of machine models lets us prepare a cross-reference sheet covering every unit in your inventory.

Frequently Asked Questions

Q: How do I confirm this K03 turbocharger fits my exact Bobcat or Doosan model? A: Send us the machine model and the Doosan D34 engine serial prefix from the data plate. We cross-check the serial range against our fitment database to confirm port orientation, flange bolt pattern, and actuator calibration. If the data plate is unreadable, a photograph of the existing turbocharger's oil flange and exhaust outlet allows visual identification.

Q: My old turbo number does not match any listing — is it superseded? A: Many early production numbers for this K03 platform have been superseded across machine generations. We verify superseded numbers across the 150105-00344 series and 5303-970/988 series to confirm the current correct variant for your specific build. Cross-reference verification covers both active and discontinued reference numbers.

Q: Why does the same base number have several variant suffixes like 150105-00344C versus 150105-00344E? A: Suffix changes typically reflect revisions to compressor housing geometry, wastegate calibration, or oil flange configuration across production years. Each suffix corresponds to a specific engine calibration and machine model range. Installing the wrong suffix variant may result in port misalignment or incorrect boost pressure despite the base number matching.

Q: I only have the machine model, no readable part number — can you identify the right turbo? A: Yes. Machine model alone is often sufficient when combined with approximate build year or engine serial prefix. Our identification process covers scenarios where nameplates are worn, painted over, or missing entirely. A photograph of the existing turbocharger from two angles helps confirm the variant when the number is not available.

Q: Can I get a sample to confirm fitment before ordering for the whole fleet? A: Sample units are available for bench fitment trials before any bulk commitment. This lets your workshop verify port positions, flange patterns, and hose connections on an actual machine before the full order ships. Sample supply is standard practice for fleet operators standardizing on a single validated source.