A technician is diagnosing a manual steering gear that exhibits excessive free play at the steering wheel, but no external leaks or abnormal noises are present. The technician notes that the input shaft has minimal rotational play, but the pitman arm shaft (sector shaft) moves excessively before the pitman arm begins to move. Which adjustment or repair is MOST likely needed?
- AAdjusting the steering gear preload.
- BReplacing the steering column universal joint.
- CAdjusting the sector shaft lash.
- DReplacing the inner tie rod ends.
Show answer & explanationAnswer & explanation
Correct answer: C. Adjusting the sector shaft lash.
Excessive free play *after* the input shaft (worm shaft) but *before* the pitman arm begins to move indicates excessive lash (clearance) between the worm gear and the sector gear inside the steering box. This lash can often be reduced by adjusting the sector shaft lash screw, which moves the sector shaft closer to the worm gear, eliminating the play. This is a common adjustment for manual steering gears with internal wear.
Why the other options are wrong
- A. Steering gear preload primarily affects the effort to turn the wheel and the feel of the steering, not excessive free play.
- B. A worn steering column universal joint would cause play in the input shaft, not solely in the sector shaft movement.
- D. Replacing inner tie rod ends would address play in the steering linkage, not internal play within the steering gear itself.
Manual Steering Sector Lash
Excessive free play in a manual steering gear, specifically in the pitman arm shaft before the arm moves, indicates excessive lash between the worm gear and sector gear, which can often be corrected by adjusting the sector shaft lash.
- Lash is clearance between internal gears.
- Causes 'dead spot' or free play in steering.
- Adjusted via sector shaft screw on steering gear.
Memory trick: Lash in the sector, adjust the screw to fix the wander.