Detroit Diesel Troubleshooting Diagrams

Series 60 engines currently use two types of pistons. Non-premium engines use pistons with cast iron domes and skirts and open-end connecting rods. Premium engines (identified by the letters “PK” or “BK” in the fifth and sixth positions of the model number) built on or after March 16, 1998 use pistons with forged steel domes, aluminum skirts, and closed-end connecting rods. High torque engines (identified with “FK” or “HK” in the model number) also uses a steel piston, but of a larger diameter (14L). ‪

Note: Steel and cast iron cylinder components must not be mixed in an engine.

The cast iron cross-head piston is a two-piece piston consisting of a dome and a skirt. The dome and skirt are held together by the piston pin. Ring grooves are machined in the piston dome.

The flywheel housing is a one-piece casting mounted against the rear of the cylinder block. It provides a cover for the flywheel and serves as a support for the cranking motor and the transmission.

The flywheel is attached to the rear end of the crankshaft with twelve bolts. The bolt holes in the crankshaft and flywheel are equally spaced. The flywheel is not indexed to the crankshaft, and may be installed in any position. A scuff plate is used between the flywheel and the bolt heads to prevent the bolt heads from scoring the flywheel surface.

Two crankshaft pulley arrangements exist. Some early engines were built with a pulley, a crankshaft pulley hub and woodruff keys. Later engines are built with the crankshaft pulley bolted directly to the crankshaft. ‪

For the crankshaft pulley bolted directly to the crankshaft, In this case the pulley is attached to the crankshaft with six special bolts and washers. The vibration damper is clamped between the crankshaft pulley and the crankshaft. ‪

The viscous damper assembly consists of a sealed outer shell, an internal flywheel and a quantity of highly viscous fluid.

A vibration damper safety shield is recommended in industrial and marine applications in which the engine operates without a hood or other protective covering in an open or unprotected area. ‪

A properly designed and installed safety shield protects the damper from damage, prevents direct physical contact with the damper during engine operation, and significantly reduces the potential for damper-related personal injury. ‪

Detroit Diesel Corporation does not manufacture, sell or install vibration damper safety shields due to the wide variety of installations in which Detroit Diesel engines are applied. Space restrictions in these numerous applications make it necessary to design an appropriate type of shield for each installation. ‪

The responsibility for designing and installing properly shaped and constructed safety shields, therefore, rests with the OEM (Original Equipment Manufacturer), distributor, or other fabricator designing or manufacturing products in which they apply Detroit Diesel engines. ‪

During operation, the outer shell, which is firmly attached to the crankshaft, turns at the same speed as the crankshaft, its motion being transferred to the flywheel through the fluid within the shell. Since “fluid-drive” is more or less inefficient with frequent speed changes, considerable flywheel slippage will take place as the power impulses are transmitted through the crankshaft. In this type of operation, the slippage is desirable since the acceleration and deceleration of the flywheel in the damper lessens the vibration amplitude, reducing its effects to a level harmless to the engine. ‪

A viscous type vibration damper is mounted on the front end of the crankshaft to reduce torsional vibrations to a safe value.

Prior to April 1993, 11.1 liter engines with less than 320 hp (238 kW) were equipped with a 313.4 mm (12.34 in.) damper and 11.1 liter engines with 320 hp (238 kW) or more were equipped with a 342.9 mm (13.5 in.) damper, and all 12.7 liter engines, were equipped with a 342.9 mm (13.5 in.) damper. ‪

The crankshaft main bearing shells are precision made and are replaceable without machining. They consist of an upper bearing shell seated in each cylinder block main bearing support and a lower bearing shell seated in each main bearing cap.

The upper and lower bearing shells are located in the respective block and bearing cap by a tang. The tang is located at the parting line at one end of each bearing shell. The tangs are offset from center to aid correct insertion. Bearing shell sets are supplied as a matched assembly and should not be mixed. ‪

A hole in each upper bearing shell registers with a vertical oil passage in the cylinder block. Lubricating oil, under pressure, passes from the cylinder block oil gallery by way of the bearing shells to the drilled passage in the crankshaft, then to the connecting rods and connecting rod bearings. The upper bearing shell is also grooved. ‪

The lower main bearing shells have no oil holes or grooves. Therefore, the upper and lower main bearing shells must not be interchanged. ‪

Current seals feature a lay down sealing lip of low-friction PTFE with unidirectional spiral pumping grooves. An outer dust-exclusion lip keeps airborne dirt away from the primary sealing lip. The sealing lip does not touch the crankshaft, because an integral wear sleeve provides the running surface and protects the lip during installation. A separate replacement wear sleeve is not needed. The wear sleeve and outer carrier are joined together, forming a unitized seal assembly. ‪

Because of the spiral grooves on the sealing lip, a front crankshaft seal will leak if installed at the rear, and a rear crankshaft seal will leak if installed at the front. ‪

Wet-flywheel-housing applications require a double-lip rear seal to prevent transmission oil from migrating into the engine. This seal is similar to the single lip seals except for the extra lip, and the wear sleeve and outer carrier are not joined together. ‪

An oil seal is fitted between each end of the crankshaft and the bores of the flywheel housing and gear case cover to retain the lubricating oil in the crankcase. In certain applications, the seal must also prevent transmission oil from migrating into the engine. Seals are pressed into the bores after the housing or cover is assembled to the engine.