A tierod end is a part of the steering linkage that relays commands from the steering wheel. Some vehicles have 4 or more.
The number 1 reason they wear out is from lack of lubrication. Years ago, every vehicle’s tierod end had a grease fitting. Not so anymore.
Most vehicles built today don’t have grease fittings in the front steering linkage or suspension balljoints.
When we replace worn tierods, we always try to buy and install better parts than what we took off the vehicle.
For example, in the photo below you can see the factory tierod end that does not have a grease fitting. You can also see the upgraded part that we installed that does have a grease fitting.
If the vehicle owner keeps this upgraded tierod end greased, they most likely will never have to replace it again.