CAT 238-8926 BEARING GP

CAT 238-8926 is a Caterpillar double-row tapered roller bearing assembly, suitable for the rear axle differential, gearbox output shaft, or hydraulic pump spindle of Cat® Parts models such as 320D/336D excavators, 966K loaders, and 140M graders. It is used to withstand radial and bidirectional axial combined loads, and is compatible with Cat C6.4/C7.1/C9 engines and Cat 345B/C/D hydraulic systems. It limits radial runout and axial movement, is suitable for medium-to-high speed heavy-duty conditions (≤3000 rpm), has a rated radial load ≥180 kN, a rated axial load ≥120 kN, and a fatigue life ≥10,000 hours, ensuring stable operation of the transmission system and preventing component wear, increased clearance, or seal failure. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 238-8926, Double row tapered roller bearing assembly (including inner and outer rings, rollers, cage, and seals), suitable for 320D/336D excavator rear axle differential, 966K loader gearbox output shaft, 140M grader hydraulic pump spindle, material is GCr15 chromium bearing steel (integral quenching HRC 60-64), cage is stamped steel plate, seal is nitrile rubber (NBR), operating temperature -40℃ to +120℃, single weight approximately 1.85 kg, suitable for SAE 15W-40 diesel engine oil lubrication, rated radial load ≥180 kN, rated axial load ≥120 kN, limiting speed 3000 rpm, fatigue life ≥10000 This type of bearing is used to withstand combined radial and bidirectional axial loads, limit radial runout and axial movement, and ensure stable operation of the transmission system.

Key Dimensions: Inner diameter 80.00 mm (tolerance H7, +0.030/0 mm), outer diameter 140.00 mm (tolerance h6, 0/-0.025 mm), width 46.00 mm (tolerance ±0.20 mm), roller diameter 12.00 mm (18 rollers per row), roller length 32.00 mm, radial clearance C3 (0.035-0.055 mm), shaft fit tolerance k6 (+0.021/+0.002 mm), bearing housing fit tolerance H7 (+0.040/0 mm)

Material and Process: GCr15 chromium bearing steel → forging → rough grinding → quenching (850℃ oil quenching) → low-temperature tempering (160℃) → precision grinding → assembly (double row rollers + stamped cage + … Inner and outer rings + NBR seals) → Rust-proof treatment, hardened layer depth 2.5-3.0 mm, possessing high hardness, high wear resistance and fatigue resistance, suitable for medium-high speed and medium-heavy load conditions of gearboxes, hydraulic pumps, and rear axle differentials, bearing radial and bidirectional axial combined loads.

Compatible models: Cat 320D/336D excavators (C6.4/C7.1 engine), 966K/972M loaders (Cat 345D hydraulic system), 140M/160M graders (C9 engine), 420F backhoe loader (C6.6 engine), used in rear axle differentials, gearbox output shafts, hydraulic pump spindles, steering knuckle pins, etc., bearing radial and bidirectional axial combined loads, limiting radial runout and axial movement, ensuring smooth operation of components.

Assembly fit: Compatible with 80 mm diameter shafts (tolerance k6, +0.021/+0.002). The bearing outer diameter and bearing housing fit tolerance is H7 (+0.040/0 mm). The contact area between the bearing end face and the mounting surface is ≥90%. After installation, the radial clearance is controlled within 0.035-0.055 mm. M24×2 bolts (grade 10.9, preload torque 160-180 N・m) are compatible.

Installation and Maintenance Points: Before installation, clean the bearing, journal, and bearing housing. Check for scratches, rust, and cracks on the surfaces. Measure the bearing inner diameter and journal diameter, and the bearing outer diameter and bearing housing inner diameter to ensure the fit meets requirements. The bearing housing surface roughness Ra≤1.6 μm, the end face is flat and free from deformation, and the journal fillet radius is ≤2.0 mm to avoid stress concentration at the roller ends.

Install using the cold mounting method, ensuring the bearing is coaxial with the journal. Do not directly strike the bearing end face with a hammer to prevent damage to the rollers or cage. After installation, check the bearing’s rotational flexibility to ensure there is no jamming or abnormal noise, and that the radial clearance meets C3 requirements. Adjust the axial preload to prevent excessive axial movement.

Maintenance Recommendations: Check the bearing’s wear condition every 2000 hours. If raceway wear > 0.15 mm, or if pitting of the rollers, cage deformation, or aging of the seals are observed, replace the bearing immediately. Regularly change the machine oil to keep it clean and prevent oil contamination from accelerating bearing wear, which can affect rotational accuracy and load-bearing capacity.