CAT 598-4378 Cab Mounting Sleeve

CAT 598-4378 is a dedicated positioning sleeve for Caterpillar cab installation. It is primarily used in the cab-to-frame connection area of ​​Caterpillar 320D/336D excavators, 966K loaders, 140M graders, and other models. Its function is to position the cab mounting bolts, buffer vibration, compensate for installation errors, ensure cab installation accuracy and stability, reduce noise and vibration inside the cab, and is compatible with Caterpillar’s four-point/six-point cab mounting system to ensure the levelness and coaxiality of the cab after installation. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 598-4378, cab mounting positioning sleeve, compatible with 320D/336D excavators, 966K/972M loaders, 140M/160M graders, 420F backhoe loaders, material is 45# steel (quenched and tempered HB 220-250), surface galvanized passivation treatment (salt spray resistance ≥96 hours), working temperature -40℃ to +120℃, single weight approximately 0.52 kg, used for positioning cab mounting bolts, buffering vibration, compensating for installation errors, ensuring cab installation accuracy, rated axial load ≥50 kN, radial deformation ≤0.10 mm

Key Dimensions
Inner diameter 30.00 mm (compatible with M30 mounting bolts, tolerance H7, +0.030/0 mm), outer diameter 45.00 mm (tolerance…) H6 (0/-0.016 mm), total length 50.00 mm (tolerance ±0.10 mm), chamfered ends C1.5 mm, sleeve wall thickness 7.50 mm, bolt and sleeve fit clearance 0.05-0.10 mm, sleeve and mounting hole interference fit 0.015-0.030 mm, mounting hole diameter 45.00 mm (tolerance H7, +0.030/0 mm), positioning step height 5.00 mm (tolerance ±0.05 mm).

Material and Process: 45# steel → forging → rough turning → quenching and tempering (860℃ quenching + 600℃ tempering) → finish turning → galvanizing and passivation → precision grinding. Possesses good strength and toughness, suitable for vibration and impact conditions in the cab mounting area, preventing bolt loosening and sleeve deformation.

Compatible Models: Cat 320D/336D excavators, 966K/972M This four-point/six-point mounting system is used for connecting the cab and chassis of loaders, 140M/160M graders, and 420F backhoe loaders. It positions M30 mounting bolts, buffers vibrations transmitted between the engine and chassis, ensures cab levelness (≤0.5°) and coaxiality (≤0.10 mm), and reduces cab noise (≤85 dB).

Assembly Fit: Compatible with M30×3.5 mounting bolts (tolerance h6, 0/-0.016 mm). The sleeve and mounting hole have an interference fit of 0.015-0.030 mm. Pressing force is 1-2 tons. After installation, the sleeve end face should be flush with the chassis mounting surface, and the positioning step should precisely fit the cab mounting hole. Bolt preload torque is 280-300 N・m (M30 bolt, grade 10.9). The sleeve and bolt coaxiality is ≤0.05 mm.

Installation and Maintenance Points: Clean the sleeve, mounting hole, and M30 bolt before installation. For bolts, inspect the surface for scratches, rust, and burrs. Measure the outer diameter of the sleeve and the inner diameter of the mounting hole, as well as the inner diameter of the sleeve and the outer diameter of the bolt, to ensure the fit meets requirements. The surface roughness of the mounting hole Ra ≤ 1.6 μm, and the end face should be flat and free from deformation.

Use a cold pressing method (using a dedicated pressing tool) to vertically press the sleeve into the mounting hole, ensuring the end face of the sleeve is flush with the frame mounting surface. Do not use a hammer to directly strike the sleeve, as this may deform or damage the mounting hole. After installation, check that the positioning step fits tightly with the cab mounting hole without gaps.

Maintenance Recommendations: Check the fit between the sleeve and bolt every 2000 hours. If loosening, deformation, or galvanized layer peeling occurs, replace immediately. Avoid subjecting the cab to excessive impact loads in daily life to prevent sleeve overload failure, which could affect the cab installation accuracy and stability.