10E-22-21320 Friction Plate for Komatsu Bulldozer D20 D21

Description

Product Overview

The 10E-22-21320 steel separator plate is a key component in the steering clutch assembly of Komatsu D20 and D21 series bulldozers (Series 6, 7, 8 and later models). This steel disc works in alternating stack with friction discs (104-22-33321 / 103-22-31310) to transfer torque from the transmission to the final drive during engagement, and allows independent track rotation during steering maneuvers when the clutch is released.

Also referenced in some parts catalogs alongside the steering clutch set, this internal-tooth steel separator plate provides the rigid mating surface against which the friction material engages. The clutch pack in D20/D21 bulldozers uses a dry-type multiple disc configuration with 8 steel drive plates and 8 driven friction discs per side.

Compatible models include Komatsu D20A, D20P, D20E, D20PL, D21A, D21P, D21E, and D21PL (Series 6 through Series 8 and later). Note that earlier D20/D21 models use a larger diameter clutch assembly (231mm friction discs, 220mm steel plates) with different part numbers.

Physical Specifications

This steel plate features precision-machined internal splines that engage with the clutch hub, providing positive drive engagement. The flat, smooth working surfaces are hardened to resist wear and maintain dimensional stability under cyclic loading and thermal stress from clutch engagement energy.

Role in the Steering Clutch System

The Komatsu D20/D21 bulldozer uses a multiple-disc dry-type steering clutch combined with an external band-type steering brake. The inner splined clutch hub also serves as the brake drum. Steering clutch disengagement and steering brake application are operated through control levers with dual mechanical linkage.

How the System Works

1. Engaged (driving): Springs press the alternating stack of friction discs and steel plates together. Torque flows from the bevel gear shaft through the clutch to the final drive, driving the track forward or backward.
2. Disengaged (steering): Pulling the steering lever moves the release bearing, compressing the clutch springs and separating the plate stack. The track on that side stops receiving power, allowing the machine to turn.
3. Braking: Further lever movement applies the external band brake around the clutch drum, providing braking force for tighter turns or stopping one track.

The steel separator plates serve two critical functions: they provide a consistent, wear-resistant mating surface for the friction material, and they distribute clamping force evenly across the friction disc surfaces for uniform torque transfer.

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

Wear Limits and Inspection Criteria

Proper inspection of steel separator plates is essential for reliable clutch operation. Steel plates that are worn, warped, or scored will accelerate friction disc wear and reduce torque transfer capacity.

Inspection Checklist for Steel Plates

• Surface condition: Plates should have smooth, uniform surfaces. Replace if pitting, scoring, or grooving is present.
• Flatness: Check for warping using a straightedge and feeler gauge. Replace if warped beyond specification.
• Spline condition: Inspect internal spline teeth for wear, chipping, or deformation. Worn splines cause uneven engagement and vibration.
• Cracks: Inspect edges and spline roots for cracks. Cracked plates must be replaced immediately.
• Heat damage: Blue or brown discoloration indicates overheating from excessive slip. Replace affected plates and identify the root cause.
• Oil contamination: If friction material is contaminated with oil (from seal leaks), both friction and steel plates should be cleaned or replaced.

Clutch Pack Configuration

The D20/D21 steering clutch (late model, Series 6+) uses the following plate configuration per side:

Important: Always replace the complete set of friction discs together. When replacing steel plates, replace all plates in the stack to maintain uniform thickness and parallel surfaces. Mixing new and worn plates causes uneven pressure distribution and accelerated wear.

Related Components

• Pressure plate / platen: Inspect working surface for wear and warping
• Clutch springs (103-22-31210): Check free length and tension; replace weakened or broken springs
• Release bearing (103-22-22221): Inspect for smooth operation, replace if noisy or stiff
• Inner drive drum (103-22-31110): Check spline condition and structural integrity
• Brake drum (103-22-31131/31132): Inspect brake surface for scoring and wear

Replacement Procedure Overview

Steering clutch replacement on D20/D21 bulldozers is a medium-difficulty repair requiring 4-8 hours per side depending on technician experience and available tooling.

1. Preparation: Position machine on level ground, engage parking brake, and block tracks securely. Drain final drive / steering clutch oil.
2. Disassembly: Remove track and final drive assembly, or access through rear inspection cover depending on service approach. Remove brake band assembly, lock springs, and locating pins.
3. Clutch removal: Release pressure and withdraw the clutch drum and disc pack assembly.
4. Inspection: Disassemble the plate stack. Inspect each steel plate and friction disc individually. Measure thickness and compare against wear limits.
5. Replacement: Replace worn components. Clean all reusable parts thoroughly. Replace seals and gaskets.
6. Reassembly: Alternate steel plates and friction discs in the correct sequence. Install springs, pressure plate, and drum. Compress springs and install retaining hardware.
7. Adjustment: Check clutch pack clearance (released position) with feeler gauge. Adjust steering clutch and brake band according to service manual specifications.
8. Testing: Refill with specified lubricant. Test steering engagement and brake operation before returning machine to service.

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

Compatibility Verification

Before ordering, confirm this part fits your specific machine:

• Model check: Verify your bulldozer model: D20A, D20P, D20E, D20PL, D21A, D21P, D21E, D21PL (Series 6, 7, 8 or later)
• Clutch size check: D20/D21 series has two clutch sizes – late models use 190mm steel plates (this part); early models use 220mm steel plates (part 100-22-15210). Measure your existing plate diameter if model series is uncertain.
• Part number check: Cross-reference with 10E-22-21320 stamped on the plate edge if legible.
• Quantity needed: 8-12 steel plates per steering clutch side, double for both sides
• Complete clutch set: For full rebuild, order both steel plates (10E-22-21320) and friction discs (104-22-33321 or 103-22-31310)

If unsure about fitment, send us your machine model and serial number for confirmation.

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 are accepted.

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