2007 — 2009
6.7L Cummins I6 (ISB 6.7)
Diesel
Accelerate hard up a steep incline at highway speed (80-100 km/h) and monitor the instrument cluster for 'Perform Service' messages or sudden loss of power. | Note: Early 6.7L Cummins engines (2007.5-2009) suffered from severe soot accumulation in the EGR and DPF systems, especially if the truck was driven on short trips without reaching full operating temperature.
Engage overdrive under load, then decelerate and check for harsh downshifts, slipping, or shuddering when the torque converter locks and unlocks. | Note: The 68RFE 6-speed automatic transmission is notoriously weak when paired with the high torque of the Cummins engine, particularly if the truck has been tuned or used for heavy towing.
Drive over uneven road surfaces or bridge joins at 90 km/h and observe if the front end initiates a violent, self-sustaining oscillation (the infamous 'Death Wobble'). | Note: Heavy-duty RAM front suspensions have weak track bar bushings and steering linkages that wear out prematurely, leading to severe steering instability.
Turn the steering wheel fully from lock-to-lock at a complete standstill while checking for binding, pops, or excessive play, then inspect the steering shaft routing under the hood. | Note: Because these trucks are imported and converted to Right-Hand Drive (RHD) for the New Zealand market, poor-quality conversion engineering can lead to steering box misalignment and accelerated component wear.
Perform a comprehensive lube service, rotate the heavy-duty tires, and replace both the primary engine oil filter and the critical chassis-mounted fuel filter to protect the high-pressure common-rail fuel system.
Flush and service the 68RFE transmission (replace both the spin-on and sump filters), replace transfer case fluid, and change front/rear differential gear oils (crucial for trucks towing heavy trailers in NZ).
Replace the crankcase ventilation (CCV) filter element on top of the valve cover, clean the EGR valve and cooler assembly of carbon soot, and inspect all front steering joint boots.
Clean the EGR valve and EGR cooler every 80,000 km to prevent carbon buildup from sticking the valve open and causing engine hesitation.
Replace the Crankcase Ventilation (CCV) filter on top of the engine valve cover every 100,000 km to avoid high crankcase pressure, which blows out turbo oil seals.
Grease the front driveshaft double-cardan U-joint (often missed by technicians because access is extremely tight and requires a needle adapter).
Monitor coolant levels and test the chemistry to prevent cavitation and corrosion in the engine block and heater core.
Strictly adhere to 10,000 km fuel filter replacement intervals using high-quality 3-micron filters to safeguard the expensive Bosch high-pressure fuel pump and injectors.
Estimated repair costs if issues arise
Factory units fail prematurely under heavy loads. Upgrading to a built transmission with heavy-duty clutches and a billet torque converter is highly recommended for longevity.
High mileage or fuel contamination damages the injectors. A full set of 6 remanufactured injectors, plus labor for coding and installation, is a major expense.
Replacing worn ball joints, track bar, steering box, and upgrading to a heavy-duty steering linkage kit to permanently cure steering wander.
If emissions gear is clogged or failing, replacing the components with OEM units to comply with NZ Warrant of Fitness (WoF) smoke/emission regulations is very costly.
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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