SK120-5 SK135SR PC120-6 YN15V00015F1 MAG-85VP KYB MAG-85 Travel Motor Final Drive Assembly Compatible with Kobelco Komatsu Sumitomo

1. Product Overview & Wholesale Price Range

The Kayaba KYB MAG-85 / MAG-85VP Travel Motor Final Drive Assembly (OEM Part # YN15V00015F1 / 18251-11000 / MAG-85VP / MAG-85VP-2400) combines both the 2-speed axial piston hydraulic travel motor and the heavy-duty planetary gear reduction box, designed for 10-to-14-ton excavators operating under continuous muddy crawling, steep slope climbing, and rough terrain operations.

• Factory Wholesale Price: $1,800 – $3,500 USD (Direct manufacturer pricing — Save up to 50% vs regional dealer markups)
• MOQ & Bulk Discount: 1 Unit (Tiered wholesale discounts available for batch container orders)
• Lead Time: 1–3 business days (Large factory stock ready for immediate worldwide dispatch)
• Warranty: 12 Months full replacement warranty with 100% bench pressure test video proof

2. Application Worksite Checklist (施工场景清单)

High-torque planetary gears engineered to deliver reliable track driving power across harsh jobsite environments:

• Highway Construction & Earthmoving: High continuous track speed under heavy soil hauling with Kobelco SK135SR short-radius excavators.
• Deep Trenching & Steep Incline Digging: High climbing torque prevents track slipping when traveling up steep ditch slopes on Komatsu PC120-6 excavators.
• Forestry Land Clearing & Swampy Ground: Floating mechanical seals protect internal planetary gears against mud, water, and debris ingress.
• Demolition & Heavy Breaker Operations: Heavy-wall cast iron housing absorbs continuous track impact vibration from rock hammers.

3. Travel Motor Final Drive Troubleshooting & Diagnostic Guide (行走马达常见故障排查)

If your 10–14 ton excavator travel mechanism is exhibiting driving failure, consult the diagnostic guide below:

• Fault 1: Machine Off-Track / Deviating to One Side During Straight Travel (单边行走跑偏)
  Root Cause: Severe volumetric oil bypass across the cylinder block valve plate or worn piston slippers in one travel motor.
  Solution: Replace with a complete drop-in MAG-85VP travel motor assembly (OEM YN15V00015F1) to restore dual-track torque balance.
• Fault 2: Weak Crawling Torque / Unable to Climb Steep Inclines (爬坡无力/行走瘫软)
  Root Cause: Main travel relief valve springs worn out or internal swashplate shoe friction galling.
  Solution: Recalibrate travel relief valve pressure or swap the complete pre-tested MAG-85VP final drive unit.
• Fault 3: Abnormal Metallic Chattering & Grinding Noise From Reduction Gearbox (减速机异响/齿轮打齿)
  Root Cause: Broken teeth on planetary sun gears or severe race pitting on main drive shaft bearings.
  Solution: Inspect final drive oil for metallic filings and install a factory-new MAG-85VP travel gearbox assembly.
• Fault 4: Gear Oil Leakage From Floating Seal / Drive Shaft Area (浮动封/驱动轴封漏油)
  Root Cause: High casing backpressure caused by a clogged motor drain line, or worn mechanical duo-cone floating seal rings.
  Solution: Flush casing drain line and replace with high-pressure duo-cone floating seal group.
• Fault 5: Travel Speed Switching Failure / Locked in Low Speed (高低速无法切换/单速死锁)
  Root Cause: Sticking 2-speed shifting pilot spool or damaged swashplate control piston seals.
  Solution: Clean 2-speed pilot shift valve gallery or replace complete MAG-85VP motor control block.

4. Hot Machinery Replacement Parts Recommendation (5大品类热门推荐表)

Explore our factory-direct replacement hydraulic components compatible with major global excavator brands:

5. Frequently Asked Questions & Technical Support (QA 问答专区)

Q1: How do I verify if this KYB MAG-85VP travel motor fits my Kobelco SK135SR or Komatsu PC120-6 excavator?
A: Check your original travel motor tag for OEM part numbers YN15V00015F1, 18251-11000, or MAG-85VP stamp. You can also send us photos of your sprocket bolt holes and oil hose connection pattern for instant verification.

Q2: My Kobelco SK135SR excavator travels off-track to the left side. Will replacing the MAG-85VP motor solve this?
A: Yes, off-track deviation during straight travel is caused by internal volumetric bypass in the weak side travel motor. Installing our new pre-tested MAG-85VP travel motor restores equal dual-track drive torque.

Q3: Is this Kayaba KYB MAG-85VP travel motor final drive bench tested before shipment?
A: Yes, every single MAG-85VP travel motor undergoes a high-pressure hydraulic bench test verifying 2-speed shifting, gear torque output (up to 320 Bar), and mechanical duo-cone floating seal tightness.