Repair of the Liebherr D924 Engine in the LTM 1080/1 Crane

Engine Overhaul of Liebherr D924 in Mobile Crane LTM 1080/1

The Liebherr LTM 1080/1 mobile crane is a versatile and extremely robust machine used in assembly, construction, and industrial work. Thanks to its mobility, compact dimensions, and high lifting capacity, this model has been recognized for years among companies executing demanding projects. A key element ensuring the reliable operation of the entire machine is the Liebherr D924 diesel engine with a power range of approximately 120-150 kW, which is responsible for driving the working systems and the mobility of the crane.

The Liebherr D924 engine is a diesel unit designed for use in off-highway machines. It features a compact design, high operational culture, and great resistance to prolonged loads. Like any diesel engine operated in harsh conditions, after many thousands of operating hours, it requires professional service or a comprehensive overhaul. In this case, the reason for the report was a gradual loss of power, increased oil consumption, and smoking, indicating natural wear of the engine's internal components.

Preliminary Diagnostics and Confirmation of the Fault Cause

The first stage of work was preliminary diagnostics conducted directly on the Liebherr LTM 1080/1 crane at the client's site. Our mobile service reached the vicinity of Katowice, where the machine was being used on one of the industrial projects. During the inspection, we checked the basic operating parameters of the Liebherr D924 engine, such as oil pressure, operating temperature, and the unit's response to load.

In the next step, a compression pressure measurement was performed in the cylinders, which showed significant differences between the individual cylinders. Additionally, increased smoking under load and higher than nominal oil consumption were noticeable. Based on these symptoms, we preliminarily classified the engine for overhaul due to high mileage and natural wear of the crank-piston system. To unequivocally confirm the extent of the damage, a decision was made to dismantle the power unit and transport it to our workshop in Kojszówka.

Dismantling the Liebherr D924 Engine from the LTM 1080/1 Crane

The dismantling of the engine from the Liebherr LTM 1080/1 mobile crane was carried out by our mechanics while adhering to all safety standards and service procedures. According to the standard, a crane provided by the client was used to remove the engine. Before starting the work, all auxiliary systems were disconnected, including the cooling system, air intake, exhaust system, and fuel installation.

Particular attention was paid to properly securing the hoses, electrical harnesses, and accessory components to avoid damage during the operation. After unscrewing the mounting brackets and disconnecting the clutch, the Liebherr D924 engine was precisely lifted and prepared for transport. The entire dismantling process went smoothly, allowing for the quick transfer of the unit for further workshop work.

Verification of the Engine in the Workshop

After delivering the Liebherr D924 engine to our technical facility in Kojszówka, we proceeded with a detailed verification. The process began with an attempt to turn the crankshaft and a preliminary visual inspection. The engine was then completely disassembled into its basic components, and all parts were washed and assessed for wear.

Significant wear of the cylinder liners, pistons, and rings was confirmed, which directly corresponded to the drop in compression and increased oil consumption. Additionally, the crankshaft bearings showed signs of natural wear, but the shaft itself was suitable for regeneration. The engine head required complete regeneration due to wear of the valve seats and guides.

Repair and Regeneration Process of the Liebherr D924 Engine

The scope of repair work included a comprehensive rebuild of the Liebherr D924 engine. The first step was to regenerate the crank-piston system. The crankshaft was measured, and then it was ground and thoroughly cleaned of oil passages. New main and connecting rod bearings were used, and the connecting rods were verified for geometry and weight.

New pistons, rings, and cylinder liners were installed in the engine, restoring the factory operating parameters of the unit. The engine head underwent complete regeneration, including planning, replacement of valve guides, valves, and leak testing. The fuel system was checked, and accessories such as the turbocharger, starter, and alternator underwent detailed technical verification.

After completing the regeneration work, the engine was professionally reassembled, adhering to the tightening torques and procedures of the Liebherr manufacturer. Each stage of assembly was documented, and the engine was prepared for testing.

Test on the Engine Dynamometer

One of the key stages of our service is the engine test on the dynamometer, which is a significant asset and distinguishing feature of WIBAKO compared to competitors. After the overhaul, the Liebherr D924 engine was mounted on the dynamometer and started under controlled conditions. For the first several operating hours, it worked under a load of 20-30 percent, allowing for proper bedding of all components.

Subsequently, the engine was repeatedly loaded to nominal values, and our specialists monitored parameters such as oil pressure, operating temperature, stability of revolutions, and response to load changes. The dynamometer test allows for detecting any irregularities before installation in the machine, giving the client assurance that the engine is fully operational. After completing the tests, the unit met all technical requirements and was ready for reinstallation in the crane.

Installation of the Engine in the Liebherr LTM 1080/1 Crane

The installation of the overhauled Liebherr D924 engine was carried out again at the machine's operating site, in the vicinity of Katowice. The installation process was executed by our mobile service in cooperation with the crane operator. The engine was seated in the compartment, precisely positioned on the mounting brackets, and connected to the drive system.

During the installation, the air piping elements were replaced, all connections were checked for tightness, and the cooling system and fuel installation were connected. After replenishing the operating fluids, the first start of the engine was performed in the presence of the operator. The tests confirmed the correct operation of the unit, no leaks, and the crane's full readiness for further operation.

Summary and Further Service Support

The comprehensive overhaul of the Liebherr D924 engine restored full functionality and reliability to the LTM 1080/1 mobile crane. Thanks to the regeneration of key components and dynamometer tests, the client received a power unit with parameters close to factory specifications, covered by a warranty.

After the overhaul, we recommend performing the first service inspection after 50 operating hours, which is carried out by our mobile service. Subsequent inspections should take place every 250 operating hours, ensuring long and trouble-free operation of the engine. WIBAKO specializes in the service of construction machines and the service of Liebherr diesel engines, offering comprehensive support at every stage of machine usage.