708-8F-00171 708-8F-00170 Final Drive Assembly Aftermarket for Komatsu PC200-7 PC210LC-7

Premium Replacement Travel Motor for Komatsu Dash-7 Excavators

Get your machine moving again with our heavy-duty aftermarket final drive assembly, designed as a 100% direct drop-in replacement for Komatsu OEM part numbers 708-8F-00171 and 708-8F-00170. Engineered specifically for the Komatsu PC200-7 and PC210-7 series excavators, this complete travel motor group provides OEM-equivalent torque, speed, and durability at a fraction of the dealer cost.

Key Features:

• Universal Fit: This complete assembly is symmetrical and fully interchangeable. It can be installed on either the left or right side of your excavator's undercarriage without any modifications.

• Dual-Speed Automatic Motor: Features an integrated hydraulic 2-speed shifting valve, automatically adjusting between high speed for travel and low speed for heavy torque climbing.

• Rugged Planetary Gearbox: Built with heat-treated, high-strength gears to withstand the extreme pressures of construction, mining, and forestry applications.

• Ready to Install: Comes fully assembled with the hydraulic motor, wet multi-disc parking brake, and planetary reduction gearbox.

  
  

Common Faults & Troubleshooting

Unlike engine or electronic components, the final drive on a Komatsu Dash-7 excavator is a hydro-mechanical unit. Failures typically present as physical symptoms rather than specific dashboard electronic fault codes. If you experience travel issues, check the following:

1. Excavator Pulling to One Side (Travel Deviation)

• Phenomenon: The machine steers to the left or right during straight travel.

• Troubleshooting: First, swap the left and right main pump hoses to rule out a main pump issue. If the issue remains on the same side, the internal rotary group (pistons, cylinder block, or valve plate) of that specific travel motor is severely worn, causing excessive internal leakage. The motor assembly needs replacement.

2. Weak Travel Power / Fails to Climb Slopes

• Phenomenon: The excavator moves slowly, lacks torque on inclines, or the auto-shift (high/low speed) fails to engage.

• Troubleshooting: Check the travel pilot pressure and the main relief valve pressure (Standard is approx. 350 bar / 35 MPa). If pressure is normal, inspect the 2-speed shifting spool inside the motor for sticking, or check if the wet parking brake is failing to release fully due to low release pressure (needs to be ≥ 2.0 MPa).

3. Hydraulic Oil Mixing into the Gearbox (Over-pressurization)

• Phenomenon: Thick gear oil is pushed out of the gearbox breather plug, or the gearbox fluid level is inexplicably high and thinned out.

• Troubleshooting: The main shaft seal separating the hydraulic motor and the reduction gearbox has blown. This is almost always caused by excessive back-pressure in the case drain line. You must clean the drain line and replace the final drive seals (or the entire unit if gears are damaged).

4. Gear Oil Leaking from the Sprocket Hub

• Phenomenon: Heavy gear oil drips from the gap between the rotating sprocket hub and the stationary motor housing.

• Troubleshooting: The lifetime floating seal (mechanical face seal) has failed. Immediate replacement is required; otherwise, dirt and water will enter the planetary gears, causing catastrophic mechanical failure.

Installation & Maintenance Guidelines

To ensure maximum lifespan and keep your 6-month warranty valid, strictly follow these installation procedures for the 708-8F-00171 / 708-8F-00170 final drive:

1. Clean and Inspect the Case Drain Line (CRITICAL)Before installing the new travel motor, you MUST blow out and completely clean the case drain line returning to the hydraulic tank. Komatsu travel motors are highly sensitive to back-pressure. Ensure the back-pressure is strictly under 0.2 MPa (2 bar). A clogged drain line will instantly blow the motor's internal oil seal, which is not covered under warranty.

2. Pre-fill the Motor Housing (Hydraulic Side)Before starting the excavator engine, you must manually pour clean hydraulic oil into the uppermost case drain port of the motor housing. Starting the machine with a dry motor will cause immediate scoring of the brass internal components.

3. Fill the Gearbox (Reduction Side)The planetary gearbox is shipped dry or with minimal protective oil. Before operation, fill the reduction gear section with SAE 90 or 80W-90 (API GL-4 / GL-5) heavy gear oil. Ensure the final drive is rotated so one plug is at the top (12 o'clock) and one is at the middle (3 or 9 o'clock). Fill through the top until oil flows out of the middle plug. Do not overfill.

4. Bleed the System & TestAfter installation and filling, run the excavator at low idle. Lift the newly installed track off the ground using the boom/arm. Slowly rotate the track forward and backward several times in the air to bleed trapped air from the hydraulic lines. Check for any abnormal noises or leaks before putting the machine under load.

5. Routine Maintenance Schedule

• First 100 Hours (New Install): Drain and replace the gear oil to remove initial break-in metal particles.

• Every 500 Hours: Check the gear oil level and inspect for external leaks.

• Every 1,000 Hours: Drain and replace the gear oil with fresh SAE 90 / 80W-90.