A steering pull problem that forces you to maintain constant pressure on the steering wheel is hard on you, the driver, and hard on the tires. A vehicle with a pull problem has something amiss that is causing the vehicle to follow a path all its own.
"Steady pull" is when the vehicle continually pulls or drifts to one side even when traveling straight. The driver must maintains steady pressure on the wheel to keep the vehicle on the road. Possible causes include:
Too much cross-camber can make a vehicle pull or lead towards the side. Causes: A bent strut or mis-located strut tower, a bent spindle, collapsed control arm bushing, weak or broken spring, or a shifted cross-member or engine cradle. Correction: Replace worn or damaged parts, repositioning engine cradle, correcting location of strut tower, and/or reducing cross-camber to half a degree or less by readjusting camber to specifications.
Too much cross-caster can make a vehicle pull to the side that has the least (negative) caster. Causes: Bent strut, spindle or mislocated strut tower. Correction: Replace damaged part, correcting location of strut tower, and/or reducing cross-caster to half a degree or less by resetting caster to specifications.
The front wheels are with alignment specifications but the vehicle pulls to one side. Causes: Rear toe out of specifications, a bent rear axle, chassis misalignment or a stack-up of assembly tolerances in the chassis causing rear axle misalignment. Correction: Measure and compare the wheelbase on both sides, check for the presence of a thrust angle, and/or measure individual rear toe. Correct by realigning the rear axle or rear toe, or by performing a thrust angle alignment.
The pull is constant to one side and may get worse with the application of the brakes. Raise the vehicle and spin each wheel by hand to check for excessive drag. Causes: Caliper sticking, frozen or sticking piston in caliper, overfilled fluid reservoir in master cylinder (does not allow caliper pistons to retract when brakes are released), weak drum brake return springs, misadjusted drum brakes, misadjusted parking brake, misadjusted parking brake pedal switch (creates residual pressure in the master cylinder to cause drag). Correction: Readjust or repair brakes as required.
The vehicle will lead towards the side with low pressure in the front tire. Correct by inflating tires to recommended pressure.
Mismatched tires side-to-side: The vehicle will pull or lead towards the side that offers the greatest rolling resistance. Compare tire sizes, tread wear, tread styles, patterns and also the brands.
If one side of the tread is worn more than the other, the tire develops conicity. The effect is much the same as camber, causing the tire to roll towards the side which is worn most. Causes: Incorrect camber, toe and/or failure to rotate the tires periodically to even out wear. Correction: If rotating the tires side-to-side reverses the direction of the pull, the tires need to be replaced.