To determine the end of the side of the tie rod end that is bad, Know Your Parts says to grasp both ends by hand and push up and down. A pry bar should not be used for this inspection. Any free play indicates wear of the joint, a cause for replacement. It recommends against the use of any tools in testing, especially pry bars and water pump pliers.
Visual observation that reveals vertical movement of the outer tie rod or horizontal movement of the inner tie rod indicates a need for replacement of the parts. This observation should be performed when the vehicle is on the ground with an assistant turning the steering wheel from the 10:00 to the 2:00 position.
Know Your Parts recommends replacing any tie rod ends that show seal wear, perforation or stud corrosion. If lifting the seal with a putty knife reveals water, either as bubbles or liquid, replacement is in order.
Although vehicle maintenance schedules typically include inspection of tie rod ends, owners should also have them checked any time they hear a knock or ticking when the steering wheel turns, as these sounds generally indicate worn inner tie rod ends. A car that pulls to one side while driving or braking may also indicate that the tie rods need replacement.