2007 — 2009
6.7L I6 Cummins (ISB)
Diesel
Accelerate firmly from a standstill through all gears, then perform a passing maneuver at 80-100 km/h to check for transmission slip or hunting. | Note: The 68RFE 6-speed automatic transmission is prone to premature wear and overdrive clutch failure, especially on trucks that have been tuned or used for heavy towing.
Drive at 80-100 km/h over rough, uneven Kiwi chip-seal roads and hit mid-corner bumps to check for front-end stability. | Note: Worn track bars, ball joints, and steering stabilizers cause the infamous 'Death Wobble', a violent shaking of the front steering assembly.
Check the instrument cluster for emission-related warning lights (MIL/CEL) and perform a scan for active or pending DPF/EGR codes. | Note: The 2007.5-2009 6.7L Cummins was the first generation with heavy emissions gear (DPF/EGR). It is highly prone to soot clogging if driven on short, low-speed NZ trips.
Operate the HVAC controls through every mode (defrost, dash, floor) and sweep the dual-zone temperature dials from hot to cold. | Note: The plastic HVAC blend door actuators and doors inside the dashboard frequently snap, which requires a highly labor-intensive dashboard removal to repair.
Perform an engine oil and filter change, replace both the primary and auxiliary fuel filters (crucial for protecting the sensitive CP3 injection pump), and grease all front suspension Zerk fittings.
Service the 68RFE transmission by replacing both the sump filter and the spin-on cooler filter, flush the transmission fluid, and inspect/clean the EGR valve and EGR cooler of soot deposits.
Replace the crankcase ventilation filter (CCV) on top of the valve cover, perform a mechanical valve lash adjustment, and conduct a thorough inspection of the steering linkage, track bar, and ball joints.
Always use a high-quality diesel fuel additive to increase lubricity for the high-pressure common rail fuel system (especially with NZ's low-sulfur diesel standard).
Install a heavy-duty steering box stabilizer brace to prevent the steering box sector shaft from flexing under load.
Avoid excessive idling and ensure the truck gets regular highway runs to heat up the exhaust system and allow complete DPF active regeneration cycles.
Check front wheel hub bearings and universal joints on the front axle shafts for play or grease leakage at every service interval.
Ensure the engine coolant is flushed and replaced with the correct HOAT coolant formulation every 5 years to prevent internal corrosion of the heater core.
Estimated repair costs if issues arise
If the stock automatic transmission fails, upgrading it with heavy-duty aftermarket clutches, valve body, and a billet torque converter is strongly recommended over a standard OEM rebuild.
Replacing weak factory steering linkages, track bar, ball joints, and steering stabilizer with heavy-duty aftermarket components to permanently cure the 'Death Wobble'.
Soot-choked EGR valves, EGR coolers, or DPF filters require professional cleaning or component replacement to keep the vehicle legally compliant and running efficiently.
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Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer