Description
Product Overview
The Caterpillar D6H / D6R dozer and 966F loader friction plate is a versatile clutch and brake friction disc used across multiple Caterpillar machine families. This heavy-duty friction disc serves as a steering clutch component in D6H and D6R series track-type tractors, and also functions in the transmission or brake system of 966F series wheel loaders.
The Cat D6H is a medium-size track-type tractor in the 200-230 HP class with an operating weight of approximately 18-22 tons. The D6R is the upgraded R-series version with similar horsepower ratings and improved operator comfort and performance. The 966F is a popular wheel loader in the 3-4 cubic meter bucket class, widely used in construction, quarry, and material handling applications.
Common applications include Caterpillar D6H, D6R series dozers and 966F series wheel loaders. The friction disc works with steel separator plates within the clutch or brake housing to transmit torque or provide braking force depending on the specific application.
Machine Specifications
Caterpillar D6H / D6R Dozer
| Parameter | D6H | D6R |
|---|---|---|
| Engine Power (net) | ~200-225 HP | ~215-240 HP |
| Operating Weight | ~18-20 tons | ~19-22 tons |
| Blade Capacity | ~4.0-6.5 m³ | ~4.5-7.0 m³ |
| Transmission | Powershift, 3 forward / 3 reverse | Powershift, 3 forward / 3 reverse |
| Steering System | Steering clutch and brake | Steering clutch and brake |
| Clutch Type | Wet multi-disc steering clutch | Wet multi-disc steering clutch |
| Applications | Construction dozing, grading, utility work | Heavy dozing, ripping, production work |
Caterpillar 966F Wheel Loader
| Parameter | 966F Specification |
|---|---|
| Engine Power (net) | ~200-225 HP |
| Bucket Capacity | ~3.0-4.0 m³ |
| Rated Load | ~4,000 – 5,000 kg |
| Operating Weight | ~18-20 tons |
| Transmission | 4-speed powershift, forward/reverse |
| Brake Type | Wet multi-disc service brakes |
| Applications | Construction, quarry, material handling, aggregate |
Note: Exact specifications vary by configuration, attachments, and model year. Verify with official Caterpillar documentation for your specific machine serial number.
Wet Multi-Disc Clutch and Brake Technology
This friction disc operates in wet multi-disc systems, whether serving as a steering clutch in dozers or a brake/transmission clutch in loaders.
Wet Disc System Advantages
| Feature | Description | Benefit |
|---|---|---|
| Oil-immersed operation | Discs run fully immersed in transmission/axle oil | Excellent heat dissipation, no fade, long service life |
| Fully enclosed | Components sealed inside housing | Protection from dirt, dust, water, and debris |
| Multi-disc stack | Multiple alternating friction and steel plates | High torque capacity in compact package |
| Smooth engagement | Progressive friction characteristic | Smooth clutch engagement and braking |
| Hydraulic actuation | Piston activated by hydraulic pressure | Precise control, consistent apply force |
Steering Clutch Function (D6H/D6R Dozer)
In D6 series dozers, the friction discs are part of the steering clutch system that controls track speed differential for steering:
- Straight travel: Both steering clutches fully engaged – equal power to both tracks
- Turning: Inner track clutch partially or fully disengaged – inner track slows or stops
- Sharp turns: Inner clutch disengaged + steering brake applied – pivot turn
Brake / Clutch Function (966F Loader)
In 966F loaders, similar friction discs may be used in:
- Service brakes: Wet disc brakes in the axles for stopping
- Transmission clutches: Powershift transmission clutch packs for gear changes
For additional technical background on heavy equipment drive systems, see our final drive system guide.
Friction Disc Assembly Components
| Component | Function |
|---|---|
| Friction disc | Provides friction surface; lined with friction material on both sides |
| Steel separator plate | Alternates with friction disc; provides rigid counter-surface |
| Clutch / brake hub | Splined hub connected to drive shaft |
| Drum / housing | Outer housing with splines for steel plates |
| Apply piston | Hydraulically actuated piston compressing the disc stack |
| Return springs | Release clutch/brake when pressure is removed |
| Piston seals | Seal hydraulic pressure in apply chamber |
Friction Disc Construction
- Steel core plate: High-strength alloy steel core with splines for torque transfer
- Friction lining: High-performance friction material bonded to both faces
- Spline drive: Internal or external splines (depending on application)
- Oil groove pattern: Engineered groove design for optimal oil flow and cooling
Compatible Caterpillar Models
Track-Type Tractors (Dozers)
| Model Series | Models | Application |
|---|---|---|
| D6H Series | D6H, D6H LGP, D6H XL, D6H XR | Steering clutch |
| D6R Series | D6R, D6R LGP, D6R XL, D6R XR | Steering clutch |
| D6M Series | D6M, D6M LGP | Steering clutch – verify compatibility |
| D5H / D5M | Smaller D5 series | Steering clutch – verify compatibility |
Wheel Loaders
| Model Series | Models | Application |
|---|---|---|
| 966F Series | 966F, 966F II | Brake / transmission clutch |
| 950F Series | 950F, 950F II | Brake / transmission clutch – verify |
| 970F Series | 970F, 970F II | Brake / transmission clutch – verify |
| 966G Series | 966G, 966G II | Verify compatibility |
Note: Friction disc specifications can vary between different machine configurations, serial number breaks, and applications (steering clutch vs. brake vs. transmission). Always verify compatibility by checking your machine serial number in the official Caterpillar parts catalog.
Maintenance, Failure Modes, and Service
Common Failure Modes
| Issue | Possible Causes | Symptoms |
|---|---|---|
| Clutch / brake slip | Worn friction material, low apply pressure, glazed plates | Reduced performance, overheating, oil burning smell |
| Harsh engagement | Glazed plates, warped steel, uneven wear | Shock or jerk when engaging |
| Slow engagement | Worn seals, low pressure, restricted oil flow | Delayed response |
| Noise / vibration | Worn splines, damaged plates, bearing wear | Abnormal sounds during operation |
| Oil contamination | Metal particles, water, wrong oil type | Accelerated wear, reduced friction performance |
| Steering issues (dozer) | Worn steering clutch discs | Pulling, poor steering response |
| Weak brakes (loader) | Worn brake discs | Increased stopping distance |
Maintenance Recommendations
- Transmission / hydraulic oil maintenance: Regular oil and filter changes are critical for component longevity. Contaminated oil is the primary cause of premature wear.
- Monitor performance: Watch for changes in steering response, braking, or shifting quality
- Check oil condition: Inspect oil for metal particles or unusual discoloration
- Proper operation: Avoid excessive slip; use proper operating techniques
- Use correct oil: Always use Caterpillar recommended fluids
- Regular inspection: Follow scheduled service intervals for clutch and brake systems
Our replacement parts selection and maintenance guide provides additional systematic inspection procedures for heavy equipment components.
Replacement Guidelines
Technician Inspection Checklist
| Component | Inspection Points | Replace If |
|---|---|---|
| Friction discs | Measure friction thickness; check for glazing, cracks, delamination, spline wear | Worn below minimum, cracked, glazed, delaminated, or splines worn |
| Steel separator plates | Check flatness, scoring, heat discoloration, spline condition | Scored, warped, heat-damaged, or splines worn |
| Apply piston | Inspect seals, bore condition, free movement | Leaking seals, scored bore, or sticking |
| Return springs | Check free length, condition, tension | Fatigued, broken, or weakened |
| Hub / drum | Inspect splines for wear, cracks, damage | Splines worn, cracked, or damaged |
| All seals | Check piston seals, O-rings, gaskets | Hardened, cracked, leaking, or damaged |
| Oil / filter | Check condition and level | Contaminated, degraded, or low |
Replacement Best Practices
- Replace complete pack: Always replace all friction and steel discs together
- Replace all seals: Install new seals and O-rings during any clutch/brake service
- Thorough cleaning: Clean all components, housings, and oil passages before reassembly
- Proper torque: Follow Caterpillar service manual torque specifications
- Break-in period: New friction material requires bedding-in for optimal performance
- Service manual: Always use the official Caterpillar service manual for exact procedures
- Both sides: For steering clutches, service both left and right sides at the same time
Compatibility Verification
Before ordering friction discs for D6H/D6R dozer or 966F loader, confirm these details:
- Machine type: Is this for a dozer (D6H/D6R) or loader (966F)?
- Application: Steering clutch, service brake, or transmission clutch?
- Machine model: Confirm exact model and configuration
- Serial number: Have your machine serial number ready for parts cross-reference
- Disc count: Count the number of friction and steel plates
- Part numbers: Cross-reference with existing part numbers
If uncertain about fitment, send us your machine model, serial number, and application details and we will help verify compatibility.
Ordering and Supply Information
| Parameter | Detail |
|---|---|
| Product | Friction plate for Caterpillar D6H / D6R dozer and 966F loader |
| Machine Compatibility | Cat D6H, D6R track-type tractors; Cat 966F wheel loaders |
| Applications | Steering clutch (dozer) / brake or transmission clutch (loader) |
| Machine Class | 200 HP class / 18-22 ton |
| Origin | Made in China |
| Warranty | 6 months |
| Minimum Order | 1 piece |
| Unit Price | Negotiable (contact for quotation) |
| Bulk Pricing | Available for orders of 50+ pieces |
| Lead Time | 1-5 business days |
| Monthly Capacity | 1,000 pieces |
| Packaging | Neutral export packaging / wooden cases |
| Payment Methods | T/T, PayPal, Western Union |
We supply a complete range of clutch and brake components for Caterpillar equipment, including friction discs, steel separator plates, pistons, springs, hubs, drums, seal kits, and complete assemblies.
We ship worldwide from China with multiple logistics options: express courier (5-10 days to Southeast Asia), air freight (7-14 days), and sea freight (15-30 days). Both single-piece sample orders and bulk orders for parts dealerships, repair shops, and fleet operators are accepted.
Browse our complete construction equipment parts catalog or read our guide to evaluating reliable parts suppliers before purchasing.
