CAT 121-0676 328.18mm Inner Diameter Steering Clutch Retainer

CAT 121-0676 is a Caterpillar genuine steering clutch retainer, adapted for steering clutch assemblies in tracked equipment such as bulldozers. Its core function is to secure the clutch plate assembly, ensuring smooth clutch engagement/disengagement. The following are precise original factory specifications and application information, excluding replacement parts (Cat®)…

Core Technical Parameters

Item Details
Part Model CAT 121-0676 (Steering Clutch Retainer)

Product Type Heavy-duty machinery steering clutch retainer, used to position and fix the clutch plate assembly, ensuring smooth power transmission and steering control

Material Forged from 4140 alloy steel, tempered and heat-treated, tensile strength ≥900 MPa, hardness HRC 28–32, excellent impact and fatigue resistance

Key Dimensions Inner diameter 328.18 mm (12.92 in), outer diameter 410 mm, thickness 35 mm, bolt hole distribution circle diameter 370 mm, 12 evenly distributed M20×1.5 threaded holes, suitable for special fastening bolts

Single Weight Approx. 22.5 kg (49.6 lbs)

Installation Tolerances Inner hole roundness ≤0.05 mm, end face runout ≤0.08 mm, threaded hole perpendicularity ≤0.1 mm/100 mm

Sealing Design Integrated O-ring groove (inner diameter) 340 mm diameter, 3.5 mm cross-section, compatible with NBR (nitrile butadiene rubber) O-rings to prevent lubricant leakage and impurity intrusion.
Operating temperature: -40℃ ~ +120℃, suitable for engineering machinery gear oil, hydraulic oil, and other media.
Structure and core characteristics:
Rigid load-bearing structure: Forged and tempered alloy steel, providing sufficient structural strength and rigidity to withstand impact loads during clutch engagement and prevent deformation.
Precise positioning function: The inner hole and clutch hub have a clearance fit (0.08–0.12 mm), and the end face fits snugly with the clutch plate assembly, ensuring axial positioning accuracy of the plate assembly and preventing uneven wear or jamming.
Sealing and protection design: The O-ring groove design effectively seals against lubricant leakage and prevents dust, mud, and other impurities from entering the clutch, extending clutch life.
Ease of assembly: Evenly distributed threaded holes facilitate bolt tightening. After installation, end face runout testing ensures assembly accuracy, suitable for the frequent operation conditions of tracked equipment steering systems. Compatible Models and Application Scenarios

Compatible Models: CAT D6R, D7R, D8N, D8R, D8T series bulldozers, and some tracked loaders’ steering clutch assemblies.

Compatible Part: Between the steering clutch disc assembly and the clutch hub, used to fix the friction plates and steel plates, ensuring synchronous movement of the disc assembly during clutch engagement/disengagement, achieving precise steering control.

Core Purpose: To ensure the precise positioning and fixation of the steering clutch disc assembly, enabling smooth engagement/disengagement of the clutch during steering operations, transmitting power and achieving equipment steering, preventing power transmission interruption or steering loss due to fixation failure.