Description
CAT 177-5880 27.8mm Inside Diameter Handrail Mount Sleeve
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CAT 177-5880 is a Caterpillar genuine armrest mounting sleeve, a wear-resistant bushing for the cab seat armrest pivot, suitable for the armrest mounting position of mini excavators/loaders. It has an inner diameter of 27.8 mm and is used to eliminate the gap between the armrest pivot and the mounting hole and absorb vibration. It weighs about 0.08 kg, and 2 pieces are required per unit (1 for each armrest). The following is professional structured information:
Core Technical Parameters (Professional Version)
Item Details
Basic Attributes Model 177-5880, Cylindrical Positioning Sleeve, Inner Diameter φ27.8 mm (Tolerance H8: +0.033/+0.066 mm), Adaptable Armrest Shaft Diameter φ27.8 mm (Tolerance h7: 0/-0.033 mm), Operating Temperature -30℃ to +80℃, Rated Static Radial Load 5 kN
Key Dimensions Outer Diameter φ32 mm (Tolerance g6: -0.009/-0.025 mm), Total Length 22 mm, Wall Thickness 2.1 mm, Chamfer at Both Ends C0.5 mm, Mounting Slot Width 3 mm (for Snap Ring Fixing)
Material and Process The base material is 6061-T6 aluminum alloy (HB 95-105), with hard anodized inner hole surface (film thickness 15-20 μm, hardness HV) 350-400mm), outer cylindrical surface anodized (corrosion resistant), inner hole surface roughness Ra≤0.8 μm
Compatible Models: Compatible with the suspension seat armrests of Cat 306/307.5/308/309 mini excavators and 906/907 loaders. Installed between the armrest bracket and the shaft for positioning and wear reduction.
Assembly Fit: Clearance fit with the mounting hole (clearance 0.010-0.020 mm), transition fit with the shaft. Axially fixed at both ends by φ32 mm E-rings to prevent axial movement.
Installation and Replacement Points: Before installation, clean the armrest bracket mounting hole and shaft to remove oil and burrs. Measure the hole diameter and shaft diameter to ensure they meet tolerance requirements.
Use a rubber mallet to evenly tap the sleeve into the mounting hole, ensuring the end face is flush with the bracket plane. Do not tap at an angle, as this may deform the sleeve.
After installing the handrail pivot, install E-shaped retaining rings at both ends and check that the handrail rotates smoothly without jamming, with axial movement ≤0.1 mm.
Maintenance cycle: Check the sleeve wear every 2000 hours. If the inner hole wear is ≥0.2 mm or scratches appear on the surface, replace it immediately.
