CAT 7W-0388 Metallic Sleeve

CAT 7W-0388 is a locating sleeve used by Caterpillar for engine camshafts, hydraulic pump drive shafts, or gearbox shafts. Its core function is to achieve axial positioning of the shaft system, bearing preload, and control of the distance between transmission components. It is compatible with models such as 320D/336D excavators, 966K loaders, and C7/C9 engines, ensuring smooth shaft operation and preventing axial movement and abnormal wear. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 7W-0388, Shaft Positioning Sleeve, compatible with 320D/336D excavator hydraulic pump drive shaft, 966K loader gearbox secondary shaft, C7/C9 engine camshaft, material is 45# steel (quenched and tempered HB 220-250), surface hard chrome plated (thickness 0.02-0.03 mm, hardness HV 800-1000), working temperature -40℃ to +120℃, single weight approximately 0.52 kg, used for shaft axial positioning, bearing preload and component spacing control, preventing shaft movement.

Key Dimensions
Inner diameter 65.00 mm (tolerance H7, +0.030/0 mm), outer diameter 80.00 mm (tolerance h6, 0/-0.025 mm), total length 30.00 mm (tolerance ±0.10 mm). (mm), chamfered ends C1.5 mm, inner hole roughness Ra≤0.8 μm, interference fit with shaft 0.010-0.020 mm, contact gap with bearing inner ring end face ≤0.03 mm, suitable for M10 bolt fastening, torque 25-28 N・m
Material and process: 45# steel → forging → rough turning → quenching and tempering (850℃ quenching + 600℃ tempering) → finish turning → hard chrome plating (salt spray resistance ≥72 hours) → precision grinding. It possesses high hardness, high wear resistance, and good dimensional stability, suitable for medium-high speed and medium-load operating conditions.
Compatible models: Cat 320D/336D excavator hydraulic pump drive shaft positioning, 966K/972M loader gearbox second shaft bearing preload, C7/C9 engine camshaft axial positioning, 140M… The grader drive axle shaft positioning system is used to control the axial clearance of transmission components, achieve bearing preload, and prevent shaft movement and abnormal wear.

Assembly Fit: Compatible with 65 mm diameter journals (tolerance k6, +0.019/+0.002 mm), interference fit 0.010-0.020 mm, hot fitting (oil temperature 80-90℃) or cold fitting, rear end face runout ≤0.02 mm, coaxiality with adjacent components ≤0.03 mm.

Installation and Maintenance Points: Before installation, clean the sleeve, journal, and mating components, checking for scratches, rust, and burrs. Measure the inner diameter of the sleeve and the outer diameter of the journal, and the outer diameter of the sleeve and the inner diameter of the bearing inner ring to ensure the fit meets requirements. The mounting surface must be flat and free from deformation.

For the hot fitting method (immerse the sleeve in clean machine oil at 80-90℃ for 20-30 minutes), use a special tool to press it vertically into the journal, ensuring the sleeve end face fits snugly against the shaft shoulder and bearing inner ring without misalignment. For the cold fitting method, use a hydraulic nut to evenly press it in; do not strike it directly with a hammer to prevent deformation and damage.

Maintenance Recommendations: Check the sleeve’s positioning condition every 1500 hours. If wear, deformation, or plating peeling is observed, replace it immediately. Use ISO VG 46 hydraulic oil for daily lubrication to prevent dry friction from accelerating wear and affecting positioning accuracy and service life.