CAT 068-8555 RING

CAT 068-8555 is a Caterpillar genuine fuel pump tappet shaft elastic retainer ring (pure original factory information, no additional description), compatible with the high-pressure common rail fuel pump tappet assembly of C13/C15/C18 engines. It is used for axial positioning of the 068-8233 bushing and 068-8527 adjusting ring to prevent axial movement of the tappet shaft assembly under camshaft drive, ensuring stable preload clearance and injection timing accuracy (Cat®…).

Core Parameters and Information

Item Details
Part Model: CAT 068-8555 (0688555) Elastic Retaining Ring

Structure Type: Open-type shaft elastic retaining ring, radial cut with mounting lug, galvanized and passivated surface for corrosion protection

Material: 65Mn spring steel (quenched HRC47-52, galvanized surface, salt spray test ≥48 h), Weight: 0.003 kg

Key Dimensions: Inner diameter 22 mm, outer diameter 28 mm, thickness 1.2 mm, opening width 1.5 mm, mounting lug height 2 mm

Performance Parameters: Radial elastic force 80-100 N, operating temperature -40℃ to 150℃, elastic deformation ≤0.15 mm, fatigue life ≥5×10⁵ cycles

Compatibility Standard: Complies with ISO 894-1 shaft retaining ring standard, outer diameter tolerance ±0.05 mm, thickness tolerance ±0.03 mm mm Compatible Models and Assemblies

Compatible Parts: 068-6117 Bearing, 068-8233 Bushing, 068-8527 Adjusting Ring, 068-2742 Tappet Retainer

Compatible Equipment: CAT 336D2/349D2 Excavator, 980K/982M Loader, D8T/D9T Bulldozer (C13/C15/C18 Engine), used for axial positioning of the high-pressure common rail fuel pump tappet shaft

Installation: 1 piece per tappet shaft, installed in the annular groove of the tappet shaft. After clamping, the axial positioning bushing and adjusting ring work together with the 068-7875 retaining ring to prevent component movement.

Installation and Maintenance Points: Clean the retaining ring and the annular groove of the tappet shaft. Check the retaining ring for deformation, cracks, and peeling of the galvanized layer. Groove width: 1.2⁰⁺⁰・⁰² mm, groove depth: 0.6 mm. mm, surface roughness Ra≤1.6 μm.

Use dedicated snap ring pliers (075-2353) to open the retaining ring and insert it into the shaft groove, ensuring the retaining ring is fully embedded in the groove without looseness or misalignment, with the opening facing the non-load-bearing side.

After installation, check that the axial movement of the tappet shaft is ≤0.02 mm, the gap between the retaining ring and the bushing end face is ≤0.01 mm, and the fuel pump operates without abnormal noise or leakage.

Maintenance: Check the retaining ring’s elasticity every 1500 hours (replace when the outer diameter rebound is ≥0.5 mm). Replacement should be performed simultaneously with the bushing and adjusting ring checks to prevent component displacement due to retaining ring failure.