* Steering Column: Worn bearings or bushings in the steering column itself can create a knocking sound, especially when turning the wheel or going over bumps. This is a common problem in older vehicles.
* Intermediate Steering Shaft: The intermediate shaft connects the steering column to the steering gear. Worn U-joints or other components in this shaft can produce knocking.
* Steering Gear Box: Problems within the steering gear box (power steering pump and related components) can lead to knocking sounds. This could involve low power steering fluid, a failing pump, or internal wear within the gear box itself.
* Tie Rod Ends/Ball Joints: While these usually cause more of a clunking or clicking sound, worn tie rod ends or ball joints *can* contribute to a knocking noise that's felt in the steering wheel, especially when turning.
* Loose Steering Wheel: In rare cases, the steering wheel itself might be loose on the column, although this usually manifests as a wobble rather than a distinct knock.
* Suspension Components: While not directly part of the steering system, worn suspension components (control arms, bushings, etc.) can transmit vibrations and noises that might *feel* like they're coming from the steering wheel.
To diagnose the problem:
You should have a qualified mechanic inspect your Tahoe. They can perform a thorough examination of the steering system and suspension to pinpoint the source of the knocking. Attempting to diagnose and repair this yourself without experience could be dangerous. Ignoring the problem could lead to more serious issues and potentially a loss of steering control.
