Ask a Mechanic: Diagnosing clunky steering

Dear Ask a Mechanic,

For a while now, the steering in my 2014 Hyundai Sonata has had a weird, loose feeling and is a bit clunky when changing direction. It’s annoying, but it otherwise drives and steers fine. My local garage checked the front end and steering and found nothing worn or broken. They suspect it’s in the electric power steering unit, but, because it’ll be quite expensive to replace, neither of us wants to gamble on that fixing the issue. Have you come across this before? – Worried wheelman

Rarely used prior to the early 2000s, electric power steering (EPS) has become almost universal now as automakers look for ways to reduce fuel consumption. Constantly circulating pressurized fluid with an engine-driven pump takes energy, so only aiding when necessary is far more efficient. Electric operation is also necessary to provide steering assist to vehicles with stop-start systems.

There’s two ways that these systems typically operate. As the name suggests, electro-hydraulic EPS uses an electrically driven, on-demand pump rather than an engine-driven one, and the assist remains hydraulically operated, retaining a traditional “feel” while improving efficiency.

The other is fully electric, with an assist motor unit either inside the vehicle (usually under the dash) on the steering column or built into or mounted to the steering rack. Regardless of where they’re located, they work essentially the same: two or more sensors determine how hard, far and fast the driver is turning the steering, and an electric motor helps by applying an appropriate amount of force to the steering shaft or rack.

This is relevant to your car. I suspect that you have a worn drive coupling in your power steering that is causing the weird feel and noise. This is a known failure in some Hyundai Sonatas and Elantras, and certain Kia Optimas. These vehicles use a small star-shaped rubber part to absorb vibrations between the assist motor and power steering unit. The clunk and momentary loose feel you describe is created when this part wears or fails.

There is good news here, the most important being that this is not a safety issue. Second is that the automakers are aware of the problem. Hyundai Canada has the same 10 year or 160,000-kilometre extended warranty on this part as it does for U.S. vehicles. (Kia Canada did not respond by press time to confirm whether it does).

Finally, with many of these cars now falling outside of that warranty period, you should know that the part costs less than $20 and normally takes under two hours to replace, so it’s not expensive to fix.

Ask a Mechanic is written by Brian Early, a Red Seal-certified automotive technician. You can send your questions to wheels@thestar.ca. These answers are for informational purposes only. Please consult a certified mechanic before having any work done to your vehicle.