Rick's Free Auto Repair Advice

What is a tie rod?

How is a tie rod different than a drag link or center link?

A tie rod is a steering linkage component used to connect the steering gear to the steering knuckle. Most tie rods have one threaded end and an opposite end with a ball joint. The tie rod itself doesn’t wear, it’s just a steel rod. But the ball join does wear. Many consumers mistake a drag link or center link for a tie rod, but they’re not the same. Here’s a diagram of a parallelogram steering system with a recirculating ball steering gear and idler arm.

tie rod

Typical parallelogram steering gear setup showing center link, tie rod, tie rod ends and idler arm


Steering linkage used in rack and pinion steering

Rack and pinion steering systems have an inner tie rod on each side of the steering gear. The portion connected to the rack has a ball joint to allow for up and down movement on bumps and arc movement during turns. The inner rod has a ball joint style that connects to the steering knuckle. The end allows for up and down movement over bumps and pivoting during turns. Here’s a diagram showing the steering components on a rack and pinion style steering system.

tie rod end

Where the inner tie rod and outer tie rod ends are located on a rack and pinion steering gear

What goes wrong with tie rods?

The ball joint in many tie rods is permanently greased and sealed at the factory. The seal can be a rubber boot or a metal cap. Over time, the seal can fail and allow water inside the joint, causing the grease to degrade and fail. Plus, ordinary movement causes the grease to break down and fail. At that point the ball stud wears into the bearing causing “play” in the vehicle’s steering.

Other tie rods have field greasable fittings that require routine refilling. Owner neglect can cause premature joint wear and improper greasing technique can cause the seal to rupture and allow water penetration.

Tie rods transfer tremendous force from the steering gear to the steering knuckle, especially when the driver turns the wheels when the vehicle isn’t moving, like in parking maneuvers. If they’re not lubricated, they’ll wear out.

Worn tie rod endsymptoms

• A knocking sound when turning at slow speeds,

tie rod end

Example of a worn tie rod end that’s rusted and causing sloppy steering

especially during parking maneuvers.

• Squeaking noise when turning or hitting bumps is a sign that the tie rod end is bone dry

• Loose feeling or slack in the steering system. When turning the steering wheel you’ll notice a slight delay between the time you input the change and the wheels respond.

• Vehicle wander. You will notice that you must constantly correct the steering wheel to maintain a straight heading.

• The steering wheel shakes when you hit bumps

• The tire tread blocks are “feathered,” with a larger depth on the trailing edge of the tread block. In addition, since worn tie rod ends affect “toe” alignment, they can also cause tire cupping. This is due to the fact that the front of the tire is pointed slightly in toward the center of the vehicle or out.

• Tire wear on the inside or outside of the tire. This type of wear can also be cause by improper camber.

• The vehicle exhibits a constant pull to one side.

• Break or bent due to impact

tie rod

Curb impact broken inner tie rod end off the end of the steering rack

How to check for tie rod end wear?

Never squeeze a tie rod end with a pliers to check for play—that technique can permanently damage a perfectly good tie rod end. Instead, raise the vehicle and place it on jack stands. Holding the tire at the 3:00 and 9:00 position wiggle the tire while watching for movement at the tie rod ends. There should be no noticeable movement.

To learn more about steering systems and tie rod replacement cost see these posts:

For more information on power steering fluid, read this post

For more information on tie rod replacement cost, read this post

For more information on rack and pinion replacement cost, read this post

©. 2017 Rick Muscoplat


Posted on by Rick Muscoplat


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