What is a Tie Rod?

Pauline H. Gill

Tie rods transfer and control motion between components in machines and motor vehicles. Each front wheel on most automobiles has its own tie rod to connect it to the power steering unit. Six or more tie rods may also control the motion of each of the four wheels in sophisticated automotive suspension systems to deliver high-performance handling along with a smooth ride. Tie rods usually have pivoting or ball joint ends that allow the parts they connect to swivel, rock, or turn in whatever positional orientation is necessary to accomplish their function.

A roller coaster with tie rods.
A roller coaster with tie rods.

These bars are also used as connecting rods to resolve linear motion into rotating motion with crankshafts and crank wheels on machines and appliances. They allow one motor or transmission output to actuate a number of functional levers, arms, or shafts connected to it. A tie rod usually has a threaded length adjustment section that allows the rod to be tailored to the exact needs of a mechanical application. Since they can transmit large forces, they are usually made of high-strength tempered steel and plated to protect against corrosion.

Farm tractors use the tie rod mechanism extensively to control the motion of their functioning parts.
Farm tractors use the tie rod mechanism extensively to control the motion of their functioning parts.

Tie rods are extensively used for steering control on many modes of transportation besides cars and trucks. On boats and ships, they move outboard motors, stern drives, and rudders. Airplanes of all types use tie rods to connect mechanical and hydraulic actuators to flight control surfaces on wings and stabilizers. They also help raise and lower landing gear, open and close doors and hatches, and control the motion of seats and seat backs.

Riding lawn mowers, snow throwers, and many other powered implements, including farm tractors and harvesters, use the tie rod mechanism extensively to control the motion of their functioning parts. This can include height adjustments and horizontal and vertical orientation. In the living room, the tie rod allows the recliner to tilt to that just-right position for a nap. It would be practically impossible to create those exciting amusement park rides without tie rods securely connecting major components.

Tie rods play a key role in automotive performance and safety, and should be carefully inspected during periodic maintenance. While they are designed to perform reliably for many years, driving too hard over obstacles such as curbs and potholes can bend a tie rod, or pound its ends loose. While some car makers use maintenance-free tie rods, some do recommend lubrication each time the oil is changed.

Riding lawn mowers use a tie rod system.
Riding lawn mowers use a tie rod system.

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Discussion Comments


@Laotionne - From what you said, sounds like you do not have confidence in the mechanic you took your car to. The first thing you should do is find a mechanic you trust. Then you should ask him all the questions you have about tie rod repair.


@Laotionne - The ball joints on tie rods will wear out eventually. It's a good idea to have them lubed whenever you get an oil change, but I don't think most people bother with that. Most people trade in their cars before the rods have a chance to wear out. The ball joints should last at least 10 years, probably longer.

A tie rod that needs replacing is more likely to be bent. Have you hit any pot holes recently or gone too fast over railroad tracks? Either of these things could cause a tie rod to bend.

By the way, if you do have an old car and the tie rod ball joint is wore out on one wheel from all the use then you will soon have the same problem on the other front wheel unless that one has already been replaced.


I noticed a noise coming from the front end of my car. I haven't had any other problems with it lately, and it drives fine. It only makes the noise when I make turns. I took it to a mechanic and he says I need to have a tie rod replaced. Before I took the car to the garage I had never heard of a tie rod. I thought the guy might just be making something up to get more money from me.

What are some of the reasons a car would need a new tie rod? How often do they have to be replaced?

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