CAT 124-9945 BUSHING

CAT 124-9945 is a Caterpillar genuine straight-tube steel sleeve bushing, suitable for the boom, stick, or connecting rod hinges of mini excavators, skid steer loaders, and other models. It reduces friction at the hinge, bears radial loads, and positions the pin. The following is precise original part information:

Core Technical Parameters
Item Details
Part Model: CAT 124-9945 (1249945) Straight-tube sleeve bushing, weight approximately 0.8 kg (1.76 lb), suitable for pin hinge positioning applications

Core Material: Chromium-molybdenum alloy steel (42CrMo), overall heat treatment, inner bore surface hardening, hardness HRC 58-62, inner bore precision ground, roughness Ra≤0.8 μm, wear-resistant and impact-resistant, suitable for high-frequency articulated motion applications in construction machinery

Key Dimensions: Inner diameter 50.8 mm (2.00 in), outer diameter 63.5 mm (2.50 in), total length 50.8 mm (2.00 in), without oil holes or internal/external grooves, standard straight cylindrical flangeless structure.

Structural Features: Straight cylindrical design without oil grooves or holes, suitable for clearance fit installation, used to support the pin at the hinge, reducing friction between the pin and the mounting hole, bearing radial loads, limiting axial movement, and ensuring smooth swinging of the hinge.

Compatible Models: CAT 305/306/307 mini excavators (boom-stick hinge bushing), 259D/279D/289D/299D skid steer loaders (bucket linkage bushing), 416F/420F mini loaders (boom cylinder hinge bushing), etc.

Accessories: Compatible pin 124-9946, dust seal ring 124-9947, grease nipple. 124-9948 Core Functions and Installation Points

Core Functions: As a sliding bearing, it reduces friction between the pin and mounting hole at the hinge, bears radial loads, positions the pin, prevents wobbling at the hinge, ensures smooth swinging of components such as the boom and stick, and extends the service life of the pin and mounting hole.

Installation Specifications: Clean the mounting hole and bushing surface to remove oil and rust. The inner diameter tolerance of the mounting hole should be H7, and the surface roughness Ra ≤ 1.6 μm.

Use cold pressing or hot fitting (oil temperature 80-100°C). Do not hammer. Ensure the bushing fits snugly with the mounting hole without gaps. The clearance between the inner hole and the pin should be controlled within 0.05-0.10 mm.

After installation, check that the bushing end face runout is ≤ 0.05 mm and the inner hole roundness is ≤ 0.03 mm to ensure operational accuracy.

Maintenance Recommendations:

Check the hinge clearance every 500 working hours. If the clearance exceeds 0.2 mm, replace the original bushing and pin immediately to prevent hinge noise or component damage.

Use a dedicated puller during disassembly to avoid bushing deformation or damage to the inner hole, which could affect reusability.