1. Overview: What a Torque Rod Bushing Does

A Torque Rod Bushing is a critical rubber-metal component used in heavy-duty trucks such as Volvo and Freightliner to isolate vibration, control axle movement, and maintain vehicle stability. It is typically installed on torque rods that connect the axle to the chassis.

Core Functions

• Control torsional forces generated by acceleration, braking, and engine torque

• Maintain alignment between the axle and the vehicle frame

• Reduce NVH (noise, vibration, harshness) in cabin and driveline

• Absorb impact loads from uneven roads, increasing comfort and part longevity

• Extend drivetrain life by limiting excessive axle rotation

Without a healthy torque rod bushing, a heavy truck will experience axle shift, vibrations, and premature wear of suspension and drivetrain components.

2. TRB6198 Torque Rod Bushing — Key Features

The TRB6198 bushing is commonly used in torque rod assemblies for Volvo and Freightliner trucks. Designed for long-life vibration isolation, it incorporates a precision-bonded rubber-metal structure.

2.1 Structure

A standard TRB6198 bushing consists of:

Inner Sleeve (Inner Metal Tube)

• Carries the mounting bolt

• Transfers load between torque rod and chassis

• Anti-corrosion treated (phosphate or electrophoresis coating)

Outer Sleeve (Outer Shell)

• Press-fit into torque rod housing

• Ensures structural stability under high torsional loads

• Manufactured through precision machining or deep drawing

Rubber Layer (Specialty Elastomer)

• Molded and vulcanized between the inner and outer sleeves

• Provides controlled stiffness in vertical, lateral, and torsional directions

• Designed to withstand high dynamic fatigue from long-haul operations

2.2 Manufacturing Process

• Rubber formulation (NR/NBR/HNBR blends for balance of fatigue & oil resistance)

• Metal surface pretreatment (shot blasting + adhesive primer system)

• Compression molding or injection molding

• High-pressure vulcanization ensuring full rubber-metal bonding

• Post-curing and dimensional stability testing

These steps guarantee a durable, fatigue-resistant part suitable for commercial fleet environments.

3. Fitment: Volvo / Freightliner + Interchange Information

The TRB6198 torque rod bushing is widely applied in:

Applicable Truck Brands

• Volvo Trucks – heavy-duty platforms

• Freightliner – selected chassis and torque rod configurations

Note: Installation position must be confirmed by physical measurement or torque rod part number, as multiple torque rod types may exist per chassis.

Common Interchange / Cross Reference Numbers

(Example list; confirm by torque rod model)

• TRB6198

• Volvo equivalent PNs (varies by market)

• Freightliner equivalent PNs (varies by assembly version)

4. Rubber Material, Hardness & Performance

Heavy-duty torque rod bushings must withstand extreme torsional forces and long-term dynamic fatigue. The rubber layer is the core performance element.

4.1 Material Options

4.2 Key Performance Requirements

• Torsional stiffness: reduces axle wrap-up

• Durability / fatigue life: >500,000–1,000,000 cycles typical

• Oil & chemical resistance: prevents swelling in contaminated environments

• Tear strength: ensures stable operation on uneven or unpaved surfaces

5. Failure Symptoms & Causes

5.1 Common Failure Signs

• Cracks in rubber

• Rubber delamination from metal

• Knocking or clunking sound during acceleration or braking

• Vehicle drift or misalignment

• Increased vibration in cabin

• Abnormal tire wear

• Axle movement under load

5.2 Causes of Failure

• Long-term fatigue (>300,000 km typical for heavy trucks)

• Oil soak from leaking transmission/differential

• Over-torque or incorrect installation

• Excessive load / heavy hauling

• Environmental heat cycling and ozone aging

6. Replacement & Installation Guidelines

To ensure proper performance, technicians must follow correct installation procedures.

6.1 Replacement Steps (General)

1. Lift the vehicle and secure axle position

2. Remove torque rod assembly

3. Press out old bushing using a hydraulic press

4. Clean housing thoroughly

5. Lubricate press area (only metal contact surfaces)

6. Press in new TRB6198 bushing—ensure orientation is correct

7. Reinstall torque rod and torque bolts to OEM specifications

8. Recheck after first 500–1,000 km

6.2 Installation Notes

• Do not use petroleum-based lubricants on rubber

• Final torque must be applied at normal ride height

• Avoid damaging rubber layer during pressing

• Always confirm left/right orientation if applicable

7. Product Parameters (Reference Table)

8. Manufacturer Advantages — Hebei Huami New Material Tech Co., Ltd.

Hebei Huami New Material Tech Co., Ltd., established in 1998, is a national specialty rubber & engineering plastics manufacturer with strong R&D and independent compound formulation capabilities.

8.1 Certifications & Systems

• ISO9001

• IATF16949

• ISO14001 / ISO45001

• GJB9001C / AS9100D

• China Customs AEO Advanced Certification

8.2 Strengths

• 600+ employees, including 100+ R&D staff

• 47 authorized patents (19 invention patents)

• Provincial key laboratories in rubber technology

• Partnerships with CAS, multiple universities & research institutes

• Complete in-house production: raw materials → compounding → molding → testing

8.3 Production & Testing Ability

• Advanced rubber compounding lines

• Precision vulcanization molding for rubber-metal bonding

• Fatigue testing, tear/crack testing, salt spray & ozone aging testing

• Dimensional measurement (CMM)

• Custom stiffness curve tuning (torsional/axial/radial)

8.4 Customization Options

• Hardness range 50–85 Shore A

• Oil-resistant & high-temperature compounds

• Reinforced metal sleeves

• Oversized / undersized fit tolerances

• High-mileage design for truck fleets

9. FAQ 

1. What is a torque rod bushing?

It’s a rubber-metal component that controls axle movement, absorbs vibration, and maintains driveline stability.

2. What models does TRB6198 fit?

Primarily Volvo and Freightliner truck torque rods (verify actual installation position).

3. What causes torque rod bushing failure?

Fatigue, oil contamination, harsh terrain, high load, improper installation.

4. How often should it be replaced?

Typically every 200,000–400,000 km depending on load and road conditions.

5. Can rubber hardness be customized?

Yes—Huami offers 50–85A formulations, including oil-resistant NBR/HNBR.

6. How to press in a new bushing correctly?

Use a hydraulic press, lubricate only metal surfaces, and torque bolts at ride height.

7. Do you provide test reports?

Yes, fatigue, hardness, bonding, and dimensional inspection reports are available.

8. Do you offer OEM/ODM customization?

Yes, including compound design, metal sleeve modification, and stiffness tuning.