CAT 393-3670 BEARING-SLV-GD

CAT 393-3670 YM (Yellowmark) is a high-strength steel pin manufactured by Caterpillar’s authorized aftermarket brand (Yellowmark). This part is primarily used in articulated components of engineering machinery (such as connecting rods, tie rods, or small hydraulic cylinder pins) to connect moving parts and withstand shear loads.

The following is the professional structured information for this part:
Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model 393-3670 (Yellowmark brand), material is medium carbon alloy steel (equivalent to 4140 steel), unit weight approximately 0.85 kg, surface high-frequency hardened. Mainly used to withstand dynamic shear forces and radial loads.

Key Dimensions
Diameter φ45 mm (tolerance m6: +0.009 ~ +0.025 mm), Length 145 mm (tolerance ±0.2 mm). The central oil hole has a diameter of φ6 mm (through-hole), with M10×1.5 tapped ends (for disassembly or grease fitting installation), and a 2×45° chamfer at the ends.

Material and Manufacturing Process: The base material is 4140 chromium-molybdenum steel, tempered, surface induction hardened (HRC 58-62, hardened layer depth 1.5-2.0 mm), core hardness HRC 30-35. Surface blackening or galvanizing passivation treatment is used for rust prevention.

Performance Parameters: Tensile strength ≥1000 MPa, yield strength ≥900 MPa, impact energy (-40℃) ≥27 J. Rated shear load ≥350 kN, suitable for bushings with a hardness of HRC 45-55.

Compatible Models: Widely compatible with Cat 320 series excavators (such as 320D2/323/326) and 950/966 loaders. Common installation locations are the bucket link, stick tie rod, or boom cylinder lower hinge point.

YM Brand Description: Yellowmark (YM) is a premium aftermarket parts brand from Caterpillar. Compared to genuine CAT parts, it is more competitively priced, but its quality standards are lower than genuine CAT parts. It is suitable for non-core load-bearing components or repair scenarios where cost-effectiveness is a priority.

Installation and Maintenance Points:

Surface Cleaning: Before installation, the pin surface and the inner bore of the mating bushing must be thoroughly cleaned to remove old sludge and metal debris. The surface roughness must be Ra ≤ 1.6 μm.

Lubrication Assembly: Apply a sufficient amount of Cat 1U-8888 or 5P-0960 extreme pressure lithium grease to the pin surface. Pressure injection is recommended to ensure the grease fills the clearance between the pin and bushing, preventing premature wear caused by dry friction.

Match Check: This pin has a tolerance of m6, which is a transition fit. Installation typically requires gentle tapping or the use of a special clamping tool. It should not slip freely or become jammed due to excessive tightness. If the fit is too tight, do not force it in, as this may damage the inner bore of the bushing.

Axial Fixation: After installation, a cotter pin or retaining ring must be installed immediately to prevent the pin from axially dislodging under machine vibration, which could cause a serious safety hazard.

Regular Lubrication: It is recommended to add grease every 250 hours through the center grease hole or grease fitting until new grease overflows from the hinge to flush away internal wear debris.