CAT 081-9300 RETAINER

CAT 081-9300 (0819300) is a Caterpillar genuine hydraulic cylinder piston retainer for construction machinery. It is compatible with 307E2/308E2 excavators and 242D/246D skid steer loaders. It is used to secure the pistons and piston rods of the boom, stick, and bucket cylinders, preventing piston loosening and displacement during high-pressure reciprocating motion, ensuring the coaxiality of the seals, and is suitable for high-pressure and vibration conditions, preventing seal damage and hydraulic oil leakage.

Core Parameters and Information

Project Details
Part Model: CAT 081-9300 (0819300) Piston Holder

Type: Hydraulic cylinder piston holder, round nut + locking washer combination structure

Material: Round nut 40Cr alloy steel, blackened surface; Locking washer 65Mn spring steel, galvanized and passivated surface

Key Dimensions: Adapted piston rod thread M50×2, outer diameter 68mm, thickness 14mm; Locking washer inner diameter 50mm, outer diameter 66mm

Performance Parameters: Operating temperature -40℃ to +120℃, tightening torque 220N・m, anti-loosening torque ≥180N・m, tensile strength ≥1000MPa

Compatible Models: CAT 307E2/308E2 excavators, 242D/246D skid steer loaders

Matching Relationships Matching piston, piston rod, and main seal, installed at the rear end of the piston to fix its position.

Compatibility and Applications
Compatible Parts: 307E2/308E2 excavator boom, stick, and bucket cylinders; 242D/246D skid steer loader working device cylinder piston and piston rod connection, preventing piston loosening and displacement, and ensuring seal coaxiality.

Application Scenarios: Suitable for high-pressure and vibration conditions, such as high-pressure reciprocating motion of the cylinder during excavation operations. The retainer prevents piston loosening, which could lead to seal damage and leakage, ensuring hydraulic system stability.

Usage: Matching piston, piston rod, and main seal. After installation, a locking washer is used to prevent loosening, ensuring a secure connection between the piston and piston rod without relative displacement.

Installation and Maintenance Points
Installation: Clean the piston rod threads and piston inner bore, and apply thread-locking adhesive; tighten the retainer to the rear end of the piston using a torque wrench to 220 N·m; install the locking washer, ensuring the washer claws fit snugly against the retainer groove and piston end face to prevent loosening. Maintenance: Check the tightening of the retainer every 500 hours. Ensure the locking washer is not deformed or broken. If loose, retighten to the correct torque. Replace any damaged washers.

Replacement: Disassemble the old part to check for thread damage. If stripped, replace the piston rod. Before installing the new part, check the dimensions and thread accuracy. Ensure the locking washer has good elasticity.