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Views: 0 Author: Site Editor Publish Time: 01-21-2026 Origin: Site
In heavy-duty truck rear axle suspension systems, the torque rod (also called thrust rod) plays a critical role in keeping the axle precisely located. The torque rod bushing (the Mercedes truck torque rod bushing) is one of the most important rubber-metal joints in this system: it must withstand repeated torsional and shear loads while maintaining geometry stability and ride comfort under heavy loads, rough roads, hard acceleration, and severe braking. This article focuses on OEM 9423172112 and explains its replacement relationship with 9423172012 replacement, helping distributors, repair shops, and fleet buyers identify symptoms, select the right part, and improve operational reliability.
When a heavy truck accelerates, drivetrain torque tends to “pull/push” the rear axle longitudinally; under braking, the load reverses. Through shear and torsional deformation of the elastomer, the bushing limits axle fore-aft shift, preventing geometry changes that can cause abnormal tire wear, misalignment, and unstable handling.
When driving over potholes, speed bumps, or gravel roads, the axle housing and frame experience transient impacts and torsional vibrations. The rubber layer converts high-frequency shocks into elastic deformation and damping energy dissipation, reducing peak loads, protecting torque rods, brackets, and welded structures, and lowering fatigue risk.
Stable rear axle geometry improves straight-line stability and reduces drift under crosswind or load variations. A high-quality bushing balances “flexibility” and “stiffness”: it allows necessary compliance for shock absorption while maintaining sufficient stiffness in key directions to keep axle position from wandering.
The torque rod bushing is a first-line NVH isolator for the rear axle. Its hardness, damping, and bonding quality determine how effectively vibration is isolated. For heavy loads, long-haul operations, and harsh environments such as mining or construction sites, selecting a high-damping / heavy-duty durable compound is especially important.
OEM: 9423172112 (common format: 942 317 21 12)
Replacement OEM: 9423172012 (common format: 942 317 20 12)
In purchasing and RFQ scenarios, different systems may show the number with spaces, without spaces, or with different separators. It is recommended to use the full 10-digit OEM number for searching and cross-referencing.
9423172012 replacement is often used as a replacement number in similar structures or the same rear axle/suspension configurations. Whether it is a direct interchange depends on exact dimensions, sleeve sizes, rubber hardness, press-fit interference, and installation position. Before bulk purchasing, confirm with drawings/samples and validate with on-vehicle testing or bench verification.
Mercedes truck rear axle suspensions require a well-balanced performance of longitudinal control, torsional resistance, and NVH reduction. This rubber-metal bushing uses integrated vulcanized bonding between sleeves and elastomer, maintaining a stable stiffness curve under multi-direction loads—ideal for long-term heavy-duty operation.
This bushing is commonly installed at the rear axle torque rod (thrust rod) connection points between the axle housing and frame brackets. The exact location (front/rear end, upper/lower rod) varies by vehicle model and axle design. Always refer to the vehicle configuration and service manual.
A torque rod bushing generally consists of:
Inner Sleeve: mates with bolt/pin; bears clamp force and defines boundary for relative movement
Outer Shell: press-fit into the torque rod housing; provides positioning and load carrying
Elastomer: carries shear/torsional deformation and damping; the key to durability and NVH
NR (Natural Rubber): excellent resilience, fatigue resistance, and tear strength; suitable for repeated impacts and torsion
NBR (Nitrile Rubber): improved oil and media resistance; suitable for oily environments or higher oil-resistance requirements
EPDM: strong weather, ozone, and temperature resistance; suitable for large temperature swings and outdoor exposure
Material selection should match route conditions, temperature, load spectrum, contamination, and maintenance environment.
A common design range is Shore A 55–80 (customizable):
Lower hardness: better isolation and comfort, but potentially less axle control under heavy load
Higher hardness: stronger axle control and response, but higher demand on bonding and fatigue durability
Huami can recommend high-damping / heavy-duty durable formulations based on target conditions to achieve a practical balance between stability and NVH.
Most heavy-duty bushing failures are not instantaneous breaks but fatigue crack growth, thermal aging, and bonding degradation over time. Material design should focus on:
Fatigue resistance and crack growth control
Shear heat build-up resistance and compression set control
Oil/chemical resistance and ozone aging (choose system by condition)
Inner and outer sleeves operate long-term under mud, water, de-icing chemicals, and salt spray. Corrosion protection directly affects press-fit stability and future serviceability. Typical solutions include anti-rust coatings, plating, phosphating, etc. (per customer standard), combined with structural protection to reduce early looseness and noise caused by corrosion.
The core of a rubber-metal bushing is bonding. If surface prep, adhesive system, and curing curve are not well controlled, it may lead to de-bonding, voids, or interface crack propagation. A stable bonding process significantly improves durability and consistency—an important indicator when evaluating a Mercedes torque rod bushing supplier.
When the bushing loosens or rubber softens from fatigue, the axle shifts noticeably during load changes, felt as a “jerk” or rear axle shake during starting/braking.
At highway speed or under crosswind, unstable axle positioning increases steering correction frequency. Tail sway may appear, and tire wear can accelerate.
De-bonding, inner sleeve wear, or a loose press fit can cause “clunk/knock” noises during load transitions, especially on rough roads and at low speed over obstacles.
Visual signs such as rubber cracking, edge tearing, rubber-metal separation, and severe extrusion deformation usually indicate a necessary replacement.
Lift inspection: check cracks, de-bonding, offset, and corrosion
Pry-bar test: check excessive play and abnormal movement (safely)
Road test: confirm shocks/sway during acceleration/deceleration transitions
If multiple symptoms are present, replace in pairs and inspect related links/fasteners.
Use proper press tools; avoid hammering that deforms the shell or damages rubber
Clean the housing, remove burrs and rust, ensure interference fit and coaxial alignment
Avoid lubricants contaminating bonding areas (use approved assembly media per process)
Some bushings are directional (slots, marks, or eccentric design). Confirm orientation marks and ensure alignment during pressing to prevent early stress concentration.
Fleets: inspect visually and check noises per maintenance schedule
Harsh duty (mining/construction/heavy rough roads): shorten inspection intervals and monitor looseness and crack growth
Avoid chronic overloading and aggressive launch/braking
Correct rear axle alignment issues and abnormal tire wear early
Clean mud/sand regularly and check corrosion exposure
Replace in pairs and check related joints/fasteners to prevent “new part running with old faults”
As a key supplier in heavy-duty suspension rubber-metal components, Huami focuses on “compound + process + consistency + reliability validation” to deliver stable torque rod bushing supply:
30 years of experience in rubber products and rubber-metal bonded parts, serving commercial vehicles, construction machinery, high-speed rail, and more
System compliance: IATF16949, TÜV, AEO Advanced Certification (support per customer/project requirements)
In-house rubber formulation R&D: high damping, heavy-duty durability, oil/weather resistance solutions
Precision tooling and automated production: stable interference control, curing curve control, and batch consistency
Full-process quality inspection: hardness / tensile / tear / compression set / bond strength
Reliability testing: fatigue life, salt spray, oil resistance, weathering, high/low temperature cycling
Commercial support: OEM/ODM/small-batch customization, low MOQ, stable lead time for distributors and fleets
If you are sourcing a reliable Mercedes torque rod bushing supplier and want to validate interchangeability for 9423172112 / 9423172012 replacement before mass introduction, you can provide drawings/samples/working conditions for selection advice and quotation.
Note: Different models/axle/torque rod designs may vary. The table below reflects the engineering specification for this product; for bulk orders, confirm with drawings/samples.
| Item | Specification / Notes |
|---|---|
| Product Name | Mercedes Truck Torque Rod Bushing (Rubber-Metal) |
| Product Type | Rubber-Metal Torque Rod Bushing (Rear axle / suspension) |
| OEM | 9423172112 |
| Replacement OEM | 9423172012 (confirm by drawing/sample) |
| Height | 121 mm |
| Inner Diameter (ID) | 25 mm |
| Outer Diameter (OD) | 95 mm |
| Rubber Material | NR / NBR / EPDM (customizable by duty condition) |
| Hardness Range | Shore A 55–80 (customizable) |
| Metal Treatment | Anti-corrosion treatment (per customer standard) |
| Applicable Vehicles | Mercedes-Benz Trucks (confirm by actual model and position) |
| Installation Position | Rear axle torque rod / thrust rod connection points (per configuration) |
| Packaging | Neutral packaging |
| MOQ | Low MOQ |
Q1: Is 9423172012 a direct replacement for 9423172112?
A: It is often treated as a replacement, but interchangeability depends on exact dimensions, fit, hardness, and installation position. Confirm by drawing/sample before bulk orders.
Q2: What are the key dimensions of OEM 9423172112 torque rod bushing?
A: Typical spec is Height 121 mm, Inner Diameter 25 mm, Outer Diameter 95 mm. Final confirmation should match your torque rod housing and application.
Q3: Where is this bushing installed on Mercedes-Benz trucks?
A: Commonly on rear axle torque rods (thrust rods) connecting axle housing and frame brackets. Exact location varies by model/axle.
Q4: What rubber materials are available?
A: NR for fatigue durability, NBR for oil resistance, EPDM for weather/ozone resistance—customizable per operating conditions.
Q5: What hardness range can you offer?
A: Shore A 55–80 is commonly available and can be tuned for axle control vs NVH requirements.
Q6: What are common failure symptoms?
A: Rear axle shake, clunking noise, tail sway, braking/launch jerk, cracks, rubber-metal separation, and abnormal tire wear.
Q7: Do you support low MOQ and neutral packaging?
A: Yes. We support low MOQ for aftermarket/distributors and provide neutral packaging for export.
Q8: What tests ensure quality and durability?
A: Hardness, tensile, tear, compression set, bond strength plus fatigue life, salt spray, oil resistance, weathering, and temperature cycling.
Q9: Installation tips to extend service life?
A: Use proper press tools, ensure alignment, tighten bolts at normal ride height, follow OEM torque specs, and inspect related links/fasteners.
