SJ17870 Friction Plate for John Deere Tractor

Description

Product Overview

The SJ17870 brake disk is a critical friction component in the rear brake system of John Deere 5E and 5M series tractors. This internally-splined brake disc works together with brake actuating disks and friction pucks to provide reliable stopping performance for agricultural tractors used in farming operations, loader work, and field transportation.

Also cross-referenced as AL76887, AL162808, and SJ7870 in some parts catalogs, this brake disc installs in the rear brake assembly where it is clamped between friction elements when the operator applies the brake pedals. The internal spline teeth engage with the brake hub to transfer braking torque from the stationary housing to the rotating axle.

Compatible tractor models include the John Deere 5E series (5045E through 5093E) and 5M series (5100E through 5725N), covering a wide range of utility and mid-range agricultural tractors. The brake system uses a mechanically actuated design with adjustable clearance for consistent brake performance throughout the service life.

Technical Specifications

The 14 internal spline teeth provide positive engagement with the brake hub, ensuring that braking torque is transferred evenly around the circumference. The 3-pass groove pattern on the friction surfaces helps with heat dissipation and debris clearance during braking operations.

Brake System Operation

The John Deere 5E and 5M series tractors use a mechanically actuated rear brake system where the SJ17870 brake disk is a key component. The system is designed for reliable stopping performance under varying load conditions encountered in agricultural operations.

How the Brake System Works

1. Brake application: When the operator presses the brake pedal, the mechanical linkage pushes the actuating disk (L77358) and friction elements against the brake disc (SJ17870).
2. Friction generation: The friction pucks clamp against both sides of the rotating brake disc, creating friction that slows and stops the axle and wheels.
3. Brake release: When pedal pressure is released, the actuating mechanism retracts and the friction elements separate from the disc, allowing free rotation.
4. Adjustment: The system includes a lock nut mechanism for adjusting the clearance between the brake disc and friction pucks as the friction material wears.

Brake System Components

For additional technical background on heavy equipment brake and drivetrain systems, see our final drive system guide and center joint analysis.

Brake Adjustment Procedure

Proper brake adjustment is essential for safe tractor operation and even brake wear. John Deere specifies a brake clearance adjustment procedure for 5E/5M series tractors:

Adjustment Steps

1. Safety first: Park the tractor on level ground, shut off the engine, remove the key, and wait for all moving parts to stop before working on the brakes.
2. Visual inspection: Check if the brake disk is contacting the housing or if the brake lever is contacting the mounting bracket. If contact is observed, replace the friction pucks and brake disk before attempting adjustment.
3. Locate adjustment points: Access the brake assembly from the rear of the tractor. Identify the brake disk, lock nut, and friction puck assembly.
4. Measure clearance: Insert a 0.25 mm (0.010 inch) feeler gauge between the brake disk and friction puck. The feeler gauge should slide in with slight drag.
5. Adjust if needed:
   • If the feeler gauge cannot fit, loosen the lock nut to increase clearance.
   • If the feeler gauge slides in freely with no drag, tighten the lock nut to reduce clearance.
6. Verify adjustment: Remove the feeler gauge and operate the brake pedal several times. Recheck clearance and readjust if necessary.
7. Test operation: Start the tractor and test brake operation at low speed before returning to normal service.

Important: Always adjust both left and right brakes equally to prevent pulling to one side during braking. Uneven brake adjustment can cause steering drift and premature tire wear.

Compatible Tractor Models

5E Series Tractors

5M Series Tractors

Note: Always verify compatibility using your tractor model and serial number against the official John Deere parts catalog. Some model variants and special configurations may use different brake components. MFWD (mechanical front wheel drive) models use additional brake and drive disk components.

Maintenance and Replacement

Maintenance Recommendations

• Regular inspection: Check brake operation periodically. Note any changes in pedal feel, braking effectiveness, or unusual noises.
• Brake adjustment: Adjust brake clearance when wear causes increased pedal travel or reduced braking performance. Target clearance is 0.25 mm (0.010 in).
• Even wear monitoring: Check that both left and right brakes wear evenly. Uneven wear may indicate misalignment or a sticking mechanism.
• Lubrication: Keep brake linkage pivots lubricated according to the tractor maintenance schedule.
• Condition assessment: Inspect brake disk surface for scoring, grooving, heat discoloration, or excessive wear.

Replacement Indicators

Replace the SJ17870 brake disk when:

• Braking performance has noticeably decreased and adjustment no longer restores proper function
• The disk is worn significantly below original thickness (4.9 mm new)
• The disk surface is scored, grooved, or has deep wear marks from friction pucks
• The disk shows heat damage (blue/brown discoloration) from overheating
• Spline teeth are worn, chipped, or deformed
• The disk is warped or no longer flat
• The brake disk is contacting the housing or brake lever (indicating severe wear)

Replacement Checklist

Our replacement parts selection and maintenance guide provides additional systematic inspection procedures for equipment components.

Cross-Reference Part Numbers

Ordering and Supply Information

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 tractor dealerships and parts suppliers are accepted.

Browse our complete agricultural equipment parts catalog or read our guide to evaluating reliable parts suppliers before purchasing.