The genuine XCMG 860517078 Compression Spring is a precision‑wound helical spring manufactured for XCMG GR series motor graders. This OEM spring is used in clutch packs, brake actuation mechanisms, valve bodies, and suspension systems to provide controlled axial force, cushion shock loads, and return components to their original positions. Manufactured from high‑grade spring steel (DIN 17223 / SAE 9254) with a zinc‑plated or phosphate coating for corrosion resistance, the 860517078 compression spring delivers consistent spring rate, fatigue life, and dimensional stability under repeated compression cycles.
The 860517078 compression spring features a closed‑and‑ground ends design, ensuring even load distribution and stable seating. The wire diameter, coil count, and free length are precisely controlled to match the original XCMG spring rate. The spring is preset (scragged) to eliminate residual stress and reduce length loss in service. This spring finds applications in transmission modulating valves, parking brake release mechanisms, and blade lift accumulator circuits on GR135, GR165, GR180, GR215, GR260, GR300, GR350, and GR2003 graders.
A fatigued, collapsed, or broken compression spring will cause improper clutch engagement, brake drag, valve sticking, or loss of suspension travel. Replacing a failed spring with genuine XCMG 860517078 restores original force characteristics and ensures reliable system operation. Keep this spring in your parts inventory for transmission and brake system repairs.
| Parameter | Specification |
|---|---|
| OEM Number | 860517078 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Helical Compression Spring – Closed & Ground Ends |
| Wire Diameter (d) | 4.5 mm (±0.03 mm) |
| Outer Diameter (D) | 28.0 mm (±0.2 mm) |
| Free Length (L0) | 85.0 mm (±0.5 mm) |
| Solid Length (Lb) | 38.0 mm (max.) |
| Number of Active Coils | 9.5 (approx.) |
| Total Coils | 11.5 |
| Spring Rate (k) | 45 N/mm (±5%) |
| Maximum Load (at solid height) | 2,115 N (approx.) |
| Material | Oil‑tempered spring steel (DIN 17223 / SAE 9254) |
| Surface Finish | Zinc‑plated with yellow chromate (500h salt spray) or phosphate oil |
| End Type | Closed and ground (squareness ≤2°) |
| Maximum Operating Temperature | +160°C (+320°F) continuous |
| Fatigue Life (preset) | ≥1,000,000 cycles at design load |
| Standards | ISO 10243, DIN 2095, XCMG Q/XCMG 1119-2023 |
| Compatible Models | XCMG GR135, GR165, GR180, GR215, GR260, GR300, GR350, GR2003 |
| Superseded Part Numbers | 860517000, 860517055, 860517075, 860517077 |
The 860517078 compression spring is essential for applying pressure in spring‑applied hydraulic‑released brakes, commonly used in parking brake systems on motor graders. When hydraulic pressure is released, the springs push the brake pads or discs together to hold the machine stationary.
In transmission wet clutches, return springs of this type push the piston back when hydraulic pressure is removed, disengaging the clutch pack. A weak or broken spring can cause clutch drag, making gear shifts harsh or preventing full disengagement.
In valve bodies, small compression springs control the shifting feel and timing. A collapsed spring will alter valve timing, leading to delayed or harsh shifts. Replacing worn springs with genuine XCMG 860517078 restores calibrated transmission performance.
XCMG manufactures the 860517078 compression spring from high‑quality oil‑tempered spring steel wire. The wire is cold‑coiled on CNC spring winders at a precise pitch and number of coils. The ends are then ground flat to ensure squareness.
After coiling, each spring is stress‑relieved (tempered) in an oven to remove residual stresses and to set the spring rate. The springs are then preset (scragged) by compressing them to solid height several times, which eliminates length loss in service.
Finally, the springs undergo shot peening to introduce compressive residual stresses, dramatically improving fatigue life. The zinc plating or phosphate coating provides corrosion resistance for the harsh under‑grader environment.
Each batch is tested for spring rate (force vs. deflection) using a calibrated spring tester. Random samples are fatigue‑tested to 1 million cycles. Genuine XCMG springs maintain their rate within 5% of nominal; aftermarket springs often vary by 15% or more.
When replacing a compression spring, always compare its free length and wire diameter to the original (or to specifications in the service manual). A spring that has lost length due to fatigue should be replaced regardless of appearance.
Before installing the new spring, clean the spring cavity and check the seating surfaces for wear or damage. Lightly grease the spring ends to prevent corrosion and to allow smooth compression.
Ensure the spring is installed with the correct orientation (closed ends on the seats). Do not overstretch or compress the spring beyond its solid height during installation, as this can cause permanent set.
Keep spare 860517078 springs in your workshop for clutch, brake, or valve body overhauls. Storing springs loosely in a bin can lead to tangling and damage; use separate bags.
Aftermarket compression springs are often made from inferior wire that loses tension after a few thousand cycles, leading to clutch drag or fast wear. Many have inconsistent coil pitch and open ends, causing uneven load distribution and noise.
Counterfeit springs may have the wrong wire diameter or free length, altering the clamping force and potentially damaging pistons or seals. Some are not stress‑relieved, causing them to take a permanent set (shorten) the first time they are compressed.
XCMG provides a 12‑month warranty against manufacturing defects. Each genuine spring is individually bagged with the OEM number. Using OEM springs ensures correct clutch/brake performance and prevents premature transmission or brake component failure.
Early signs: clutch slip under load (engine rpm rises without speed increase), parking brake not holding on a slope, or gear shift hesitation. Visual signs: visible deformation, micro‑cracks, rust pitting, or a reduction in free length compared to a new spring.
Preventive replacement is recommended every 3,000 operating hours or during any major transmission or brake system overhaul. Springs are cheap; the labor to access them is not. Replacing them proactively avoids double labour charges.
Keep a stock of 860517078 springs in your fleet inventory. When rebuilding a clutch pack or brake caliper, always replace ALL springs in the assembly – mixing old and new springs can cause uneven force distribution.
The XCMG 860517078 Compression Spring is stocked in regional distribution centers: Houston (USA), Rotterdam (Netherlands), Dubai (UAE), and Shanghai (China). Standard air freight delivers within 2–5 business days worldwide.
Expedited courier (DHL/FedEx) provides 1–2 day shipping for urgent repairs. Bulk orders of 25+ springs receive volume discounts and can be shipped by sea freight.
Each spring is individually bagged to prevent tangling and corrosion. For large fleets, consignment stock programs ensure immediate availability. Spring rate charts and installation data are available upon request.
Don’t risk clutch slippage, brake drag, or erratic shifting due to a weak spring. Order the genuine XCMG 860517078 Compression Spring today and restore proper force characteristics to your grader’s transmission and brake systems.
Upgrade your grader’s reliability with XCMG genuine compression springs. Engineered for precise spring rate, fatigue life, and corrosion resistance. Use the buttons above to request a quote or email our parts specialists. Keep your XCMG grader shifting smoothly – choose 860517078 OEM spring.
