Renovation of the Liebherr D924 T-E Engine in the LTM 1090/2 Crane

Introduction

The Liebherr LTM 1090/2 mobile crane is a machine with impressive capabilities, used on large construction sites, in infrastructure, and for the assembly of industrial components. Under the hood of this model is the Liebherr D924 T-E diesel engine with a power output of approximately 120 kW. It is a 4-cylinder, turbocharged unit known for its durability, but like any diesel engine, after many thousands of operating hours, it may require a comprehensive rebuild.

A unit of the crane arrived at our service center reporting issues with a lack of power and difficulties in starting. Preliminary diagnostics revealed burnt valves, which clearly indicated the need for a complete engine overhaul. Thanks to our experience in servicing diesel engines and our workshop facilities in Kojszówka, we were able to carry out the repair step by step, ensuring the client a smooth return of the machine to work.

Engine Disassembly

We performed the disassembly of the Liebherr D924 T-E engine from the LTM 1090/2 crane on-site at the client's location in the Silesian Voivodeship, near Katowice. Our mobile service team, along with the crane operator provided by the client, safely removed the power unit from the machine's frame. This process required disconnecting fuel lines, air piping, cooling system components, and the electrical installation. All parts were secured and prepared for transport to our workshop in Kojszówka, where detailed verification began.

Component Verification

In the workshop, we started by disassembling the engine into parts. We paid special attention to the cylinder head, where we confirmed our earlier suspicions – the exhaust valves were severely burnt, and the valve seats required regeneration. We also checked the crankshaft, connecting rods, pistons, and cylinder liners, which showed signs of normal wear but were suitable for further operation after regeneration. The injection pump and injectors were tested on a test bench, allowing us to plan a comprehensive rebuild of the fuel system.

Regeneration and Repair

Crankshaft-Piston System

The cylinder liners were honed, the pistons were cleaned and had their rings replaced. The bearings of the crankshaft and connecting rods were replaced with new ones, and the crankshaft underwent a full inspection and measurements, confirming its suitability for further work.

Engine Head

We performed the planning of the head, replaced the guides and valves, and machined the seats. A leak test showed full functionality of the component after regeneration. As a result, the engine regained its original operating parameters and the tightness of the combustion chamber.

Fuel System

The injection pump and injectors were sent to a specialized facility, where they were regenerated and recalibrated. This allowed us to achieve optimal injection parameters, which directly translates to power and fuel efficiency.

Accessories

The turbocharger was checked for play and tightness, and then regenerated. The starter and alternator underwent electrical tests, and all wires and additional components were replaced with new or refurbished ones.

Engine Installation

After the repair was completed, the Liebherr D924 T-E engine was reassembled and prepared for installation. Our service team delivered the unit to the client and, with the help of their crane, installed it in the machine. We ensured the replacement of air piping, cooling, and fuel lines, and all connections were thoroughly checked for tightness. After the first start-up, together with the crane operator, we conducted functional tests. The engine achieved the correct operating parameters, showing no leaks or concerning symptoms.

Engine Testing on the Engine Dynamometer

One of the greatest advantages of WIBAKO service is having our own engine dynamometer. This device allows us to test power units under conditions close to actual operation. The Liebherr D924 T-E engine underwent a minimum of 16 hours of testing under a load of 20-30%, followed by multiple full load tests. We monitored oil pressure, operating temperatures, fuel consumption, and the uniformity of operation of all cylinders. As a result, the client received a tested engine, guaranteed reliability in further operation. The dynamometer ensures that every repaired unit leaves our workshop fully prepared for field work.

Post-Repair Engine Maintenance

Every engine after rebuilding receives a warranty and service recommendations from us. For the discussed LTM 1090/2 crane with the Liebherr D924 T-E engine, we recommend the first filter change after 50 operating hours. During this inspection, our mechanics also check the tightness of connections, the operation of accessories, and the overall condition of the unit. Subsequent services should be performed every 250 operating hours or at least once every three months.

Machines with the Liebherr D924 T-E Engine

The Liebherr D924 T-E engine, in addition to mobile cranes, is also found in other Liebherr machines – including wheel loaders, crawler excavators, and handling machines. Its versatility and reliability make it a popular choice in many industries.

Summary

The conducted overhaul of the Liebherr D924 T-E engine in the LTM 1090/2 mobile crane restored the machine to full functionality. Thanks to the comprehensive regeneration of the head, fuel system, accessories, and precise testing on the engine dynamometer, the client received a unit with parameters close to factory specifications. Our approach guarantees not only effectiveness but also the safety of the machine's operation. That is why WIBAKO service is a reliable partner in the field of diesel engine service and construction machinery repair.