CAT 068-8527 RING-ADJ

CAT 068-8527 is a Caterpillar genuine fuel pump tappet preload adjustment ring (pure original factory information, no additional description). It is compatible with the high-pressure common rail fuel pump tappet assembly of C13/C15/C18 engines. It is used to adjust the clearance between the tappet and the camshaft, compensate for component wear, stabilize plunger preload and injection timing, and prevent fuel pressure fluctuations, starting difficulties, or power reduction caused by abnormal clearance.

Core Parameters and Information

Item Details
Part Model: CAT 068-8527 (0688527) Tappet Preload Adjusting Ring

Structure Type: Open-type adjustable positioning ring with graduations and locking groove, galvanized and passivated surface for corrosion protection

Material: 40Cr alloy steel (tempered and tempered HRC32-38, galvanized surface, salt spray test ≥72 h), Weight: 0.012 kg

Key Dimensions: Inner diameter 22 mm, outer diameter 28 mm, thickness 2 mm, opening width 2 mm, adjustment range 0.02-0.20 mm, compatible shaft diameter 22 mm

Performance Parameters: Radial adjustment accuracy ±0.01 mm, operating temperature -40℃ to 180℃, locking torque 8-10 N・m, fatigue life ≥1×10⁶ cycles

Compatibility Standard: Complies with CAT 5K-8877 adjusting ring technical specification, radial runout ≤0.01 mm Compatible Models and Assemblies

Compatible Parts: 068-6117 Bearing, 068-8233 Bushing, 068-7875 Elastic Retaining Ring, 068-2742 Tappet Retainer

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

Installation: One piece per tappet shaft, installed between the 068-8233 bushing and the 068-6117 bearing. Adjust the preload clearance using the scale to ensure stable contact pressure between the tappet and the camshaft.

Installation and Maintenance Points: Clean the adjusting ring and mounting position. Check the ring for deformation, cracks, and clear scale. The surface roughness of the tappet shaft Ra≤0.8 μm, shaft diameter… 22⁰⁻⁰・⁰¹⁰ mm.

Set the preload clearance according to the fuel pump manual (usually 0.05-0.10 mm). Install the adjusting ring into the shaft groove, align it with the scale, and tighten it with a special tool to ensure there is no looseness.

After installation, check the tappet preload (20-30 N). The tappet shaft should rotate smoothly without jamming. The fuel pump should start without abnormal noise, and the injection pressure should be stable.

Maintenance: Check the preload clearance every 1500 hours (readjust if the deviation exceeds 0.03 mm). Avoid high temperature and vibration that could cause the adjusting ring to loosen. When disassembling, take care to protect the scale and locking structure.