CAT 488-2149 289.56mm Outer Diameter Articulating Hitch Cap

CAT 488-2149 is a Caterpillar genuine cast iron gearbox end cover (with sealing groove/locating pin hole), compatible with the front end of the swing motor gearbox of Cat 320D/323D excavators and the second shaft end cover of the gearbox of 242D/252D skid steer loaders. Its core functions are sealing the gearbox housing, fixing the outer ring of the bearing, bearing axial loads, and ensuring lubrication and positioning accuracy of transmission components. The following is complete professional information:

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model: 488-2149, Type: Gearbox End Cover (cast iron, with sealing groove, locating pin hole, mounting bolt hole), Compatible with the front end of the swing motor gearbox of Cat 320D/323D excavators and the second shaft end cover of the gearbox of 242D/252D skid steer loaders, Material: Ductile iron (QT500-7, integrally hardened), Outer diameter: φ280 mm, Inner diameter: φ120 mm, Thickness: 35 mm, Weight: Approximately 8.2 kg, rated load capacity ≥30 MPa, operating temperature -40℃ to +150℃, surface roughness Ra≤1.6 μm, flatness ≤0.02 mm, parallelism ≤0.03 mm
Key dimensions: Outer diameter tolerance ±0.15 mm, inner diameter tolerance +0.030/-0.020 mm, thickness tolerance ±0.15 mm, sealing groove width 10 mm, depth 5 mm (suitable for φ8 mm nitrile rubber O-rings), locating pin hole diameter φ12 mm (2, symmetrically distributed), mounting bolt hole diameter φ17 mm (8, distribution circle diameter φ240 mm, suitable for M16 bolts), end cap center hole and bearing outer ring clearance 0.010-0.015 mm
Material and process: Material QT500-7 ductile iron (tensile strength ≥500 MPa, elongation ≥7%), sand casting + quenching + Tempering process, surface phosphating for corrosion protection (film thickness 8-12 μm), sealing groove accuracy ±0.05 mm, locating pin hole tolerance H7, bolt hole tolerance H8, end cover flatness ≤0.02 mm, suitable bolt preload 120-150 N・m. Compatible models: Cat 320D/323D excavators (serial number JBT1000-UP) swing motor gearbox front end, 242D/252D skid steer loaders (serial number JCB1000-UP) gearbox second shaft end cover. Used to seal the gearbox/transmission housing, fix the bearing outer ring, bear axial load, prevent hydraulic oil/gear oil leakage, and ensure lubrication and positioning accuracy of transmission components. Assembly and fit: The mounting surface should be clean and free of oil/rust. Before installation, check the sealing groove for damage. Install O-rings (compatible with φ8 mm nitrile rubber O-rings, hardness 70 Shore A). The locating pin and pin hole should have an interference fit (interference amount…). 0.010-0.015 mm), bolts symmetrically pre-tightened (in 3 stages, pre-tightening force 120-150 N・m), rear end cover runout ≤0.05 mm, no leakage on the sealing surface.

Installation and Maintenance Points:

Before installation, clean the end cover sealing surface and the housing flange surface. Check the end cover for cracks/deformation/sand holes. Replace with new O-rings and apply Cat-specific sealant (Loctite 518 flat sealant) to ensure reliable sealing.

During installation, first insert the locating pin, then use a torque wrench to symmetrically pre-tighten the bolts to avoid end cover misalignment leading to seal failure or bearing positioning deviation.

Maintenance Recommendations: Check the end cover bolt torque every 1500 hours. Replace immediately if leakage or end cover deformation (flatness >0.05 mm). Regularly check the O-ring aging condition (replace if cracks/hardening occur) to prevent lubricant leakage.