CAT 110-0858 CAP SEALING

CAT 110-0858 is a bearing end cap seal used by Caterpillar for hydraulic pumps, gearboxes, or drive axles. Its core function is to seal the bearing cavity, preventing oil leakage and the intrusion of contaminants such as dust and moisture. It is compatible with the transmission and hydraulic components of machines such as the 320D excavator and 966K loader, ensuring clean sealing and proper lubrication of the bearing and cavity. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 110-0858, bearing end cap type seal, suitable for 320D excavator hydraulic pump end cap, 966K loader gearbox bearing cavity, 140M grader drive axle bearing housing, material is carbon steel (Q235, surface galvanized passivation) + nitrile rubber (NBR, hardness 70±5 Shore A), working temperature -30℃ to +100℃, single weight approximately 0.28 kg, static sealing pressure ≤0.3 MPa, sealing life ≥5000 hours, used for static sealing of bearing cavity to prevent oil leakage and contaminant intrusion.

Key Dimensions
Inner diameter 55.00 mm (tolerance H8, +0.039/0 mm), outer diameter 80.00 mm (tolerance h7, 0/-0.030 mm), total thickness 12.00 mm (tolerance ±0.12 mm). The sealing lip diameter is 55.10 mm, with a lip compression of 0.10-0.15 mm. There are 4 bolt holes with a diameter of 8.5 mm and a circumferential diameter of 65 mm. The sealing groove is 3.0 mm wide and 2.0 mm deep, suitable for M8 bolt tightening, with a torque of 18-22 N·m.

Material and Manufacturing Process: Carbon steel base → stamping → galvanizing and passivation (salt spray resistance ≥48 hours), NBR rubber sealing lip → molding and vulcanization → bonding with the base, with a bonding strength ≥1.5 MPa. It has good oil resistance and sealing performance, suitable for mineral oil hydraulic oils, and reliable static sealing performance.

Compatible Models: Cat 320D/336D excavator hydraulic pump bearing end cover, 966K/972M loader gearbox second axle bearing cavity, 140M/160M grader drive axle bearing housing, 420D… This is a skid steer loader drivetrain bearing end cap, used for static sealing of the bearing cavity, suitable for low-to-medium speed and low-to-medium pressure operating conditions.

Assembly Fit: The end cap is designed for mounting on bearings with 55 mm diameter journals. The sealing cap and bearing housing use a surface seal, with the sealing lip and journal having an interference fit (0.05-0.10 mm). The surface roughness Ra ≤ 1.6 μm, and the flatness of the sealing surface after installation ≤ 0.02 mm, with no leakage.

Installation and Maintenance Points: Before installation, clean the sealing cap, bearing housing mounting surface, and journal. Check for scratches, rust, and burrs. Measure the inner diameter of the sealing cap and the outer diameter of the journal, and the outer diameter of the sealing cap and the inner diameter of the bearing housing bore to ensure the fit meets requirements. The mounting surface must be flat and free from deformation.

During installation, apply a small amount of clean hydraulic oil to the rubber sealing lip. Align the sealing cap with the bearing housing bore and tighten evenly and symmetrically with M8 bolts. The tightening torque is 18-22 N·m. Avoid overtightening the bolts, which could deform the sealing cap or damage the lip. Ensure a tight seal.

Maintenance recommendations: Check the sealing condition of the sealing cap every 1000 hours. If oil leakage, aging, cracking or deformation of the sealing lip is found, replace it immediately. Avoid contact between the sealing cap and high temperature or strong corrosive media in daily life to prevent rubber aging and substrate corrosion, which will affect the sealing performance.