The Detroit DD15 engine is quite impressive, delivering incredible power and torque response with an extremely wide torque range, longer scheduled maintenance intervals than any other engine in its class and greater fuel economy. This model engine is a powerful workhorse, designed for dump, fire and emergency vehicles, government, construction, oil & gas refuse, regional and motor home use. This beast of an engine is a powerful workhorse that performs well while offering a smooth, clean ride to suit any drivers’ needs. The flagship DD15 engine is also compliant with the 2017 Greenhouse Gas (GHG17) standards, reducing CO2 emissions while providing better fuel economy and greatly affecting your overall operating costs.
The DD15 engine has a 1550 - 1750 LB-FT torque range, 400-505 HP horsepower range and a 14.8L displacement. The engine pull is strong, even at RPMs below 1000, since it uses an ultra-wide flat torque curve for less shifting and more usable power at lower engine speeds. When considering safety, this aspect overall greatly improves the stability of the vehicle. Noise vibration harshness (NVH) is minimized due to the sturdy rear gear train and ribbed cast iron block.
The downsped engine of the DD15 keeps your engine running longer in top gear while cruising at more efficient engine speeds, resulting in a reduction in the number of fuel injections, thus dramatically improving overall fuel economy. This engine boasts a down speed of about 400HP and a 1750lb/ft rating, with a six-blade fan to reduce power draw without sacrificing its cooling capabilities. The advanced cooling system offers a water pump with variable speed, reducing the load placed on the engine and therefore minimizing fuel consumption.
The DD15 engine has the longest scheduled required maintenance intervals in its class with easy accessibility to oil and fuel filters and a maintenance-free crankcase breather. This engine shares common service operations and parts with both the DD13 and DD16 engines, ensuring a wider part availability to get you back on the road.
After years of hauling excessive amounts of weight across thousands of miles across the United States, it may be time to rebuild your DD15 engine. Before disassembling the DD15 engine, make sure to check for misfires, check for choppy idling and look for white smoke or a fuel smell as well as any loose parts. Once disassembled, signs of leakage should be checked throughout the main points of leak paths on the engine, including possible soot tracking in the exhaust manifold area, oil wicking and tracking in the oil pan to block joint area, oil wicking in and on the flywheel housing gasket, road grime or anything else attached to the engine, oil wicking on the outside of the valve covers, oil leaking showing on the cylinder head covers, seal or gasket leaks around the fuel pump or oil compressor and any leaking around rocker cover or cam frame. Perform a soap leak test to look for any escaping air, remove the head and piston dome and check for damage. Next up is the bearing inspection for any low spots, dirt scratching or polishing. Then the pistons should be checked for any abnormal wear, stuck rings, ensure the rings and pin are free and moving well. The connecting rods and main bearings should be inspected for any significant wear. Wickness marks, scratching or wear in the crankshaft must be checked as well as the thrust bearings. Rubber seals and head gaskets must be checked for wearing and leak paths.