Tie rods make it possible to turn a vehicle’s wheel. Components on the inner and outer tie rod can include a combination of:
Tie Rod Assembly Design
Tie rods enable a vehicle’s wheels to turn in response to the steering wheel by pushing or pulling the wheel. Considered part of the steering system, they connect the steering rack to the knuckle on front wheels in cars. On heavy trucks, such as tractors and mining equipment, they are part of the axle.
These linkages are comprised of a metal sleeve with rod ends, ball joints or spherical plain bearings on either end. The ends are attached by welding, threading or crimping. Tie rods vary in length from x on an ATV or SSV to up to five feet for agriculture machines.
Referred to as inner and outer tie rods, the inner connects to a bearing housing and is covered by a seal to keep out containments. The outer tie rod is generally shorter than the inner and connects to the wheel assembly with a ball joint.
Frequently Asked Questions about Tie Rods
Can a vehicle be driven with a broken or worn tie rod?
If a tie rod is broken, the driver will not be able to steer the vehicle, so it is not possible to operate a vehicle with a broken tie rod. Worn tie rods will still function, but not accurately. Driving will be impaired due to imprecise steering and can lead to an accident.
What are symptoms of faulty tie rods?
The following indicators may be symptoms of faulty tie rods:
- A short shrieking sound, knocking or a clunky noise
- More slack in the steering wheel or vague turning capabilities
- The vehicle pulling to one side
- Shaky front wheels
- Misaligned tires
- Excessively worn tires
What causes tie rod failure?
- An impact that breaks or bends the shaft or ball joint
- Ball joints that have allowed dust or water to enter due to cracked boot seals
- Improper maintenance if ball joints require greasing and are not addressed per schedule
- Broken or cracked dust boot that allows water and other corrosive substances into the joint
- Standard wear and tear
What materials are used to make a tie rod?
Steel is one of the most important elements when making a tie rod. Quality steel means the difference between a long lasting linkage and one that succumbs to the pressures under a load.
The material used on inner and outer tie rod components is also important. Tie rods are shipped as an assembly, so it is important to work with a manufacturer who can accurately manufacture and assemble the entire tie rod to your specifications.
What questions should OEMs ask manufacturers about tie rod steel?
- Where do you buy your steel?
- Knowing the steel source is important since the standard chemical composition of chromium can vary.
- Steel from North America or Europe is considered to be among the best quality. If it is not from these regions, how does the manufacturer determine the melt source to be equal in quality?
- What kind of testing do they do to the steel?
- How can you prove that each batch meets standards? And is the steel measured against a recognized international standard or an internal standard?
- How is the steel treated?
- Strict specifications on oxygen, inclusion and carbide distribution
- Heat treatment to increase material impact load capacity
- Adding diffusion normalizing heat treatment
- Can you trace back an end product to the steel lot?
- A tie rod manufacturer who can trace the final product back to a specific steel lot, which was tested for adherence to the manufacturer’s standards, is vital for risk management.
- The ability to trace a product throughout the manufacturing process also indicates that the manufacturer takes customer specifications and internal production requirements seriously.