Jaguar X-Type Sedan and Estate (Wagon). Manual - part 106
is a structure-borne noise transmitted through the intermediate shaft and column. Rack knock can also be heard as a "thump" or impact
noise that occurs with the vehicle stationary when the steering wheel is released from a loaded position and allowed to return to rest. Noise
occurs with the engine on or off.
Rattles
Rattles are noises caused by knocking or hitting with components in the steering system. Steering rattles can occur in the engine
compartment, the suspension, or the passenger compartment . Rattles can be caused by loose parts, movable and flexible parts, and
improper clearances.
Squeaks/Scrapes
Squeaks/Scrapes are noises due to friction or component rubbing anywhere in the steering system. Squeaks/Scrapes have appeared in
steering linkages and joints, in column components and in column and steering wheel trim parts.
Weep
Weep is an air-borne noise, occasionally generated when turning the steering across lock at a constant rate. W hen present on a vehicle the
noise, once initiated can often be maintained across a large proportion of the available steering movement.
Whistle
Whistle is similar to hiss but is louder and of a higher frequency. It is also more of a pure tone noise than hiss. Whistle is air-borne and is
generated by a high flow rate of hydraulic fluid through a small restriction.
Zip
Zip noise is the air-borne noise generated by power steering pump cavitation when power steering fluid does not flow freely through the
suction hose from the reservoir to the pump. Zip primarily occurs during cold weather at start-up.
Steering System Vibrations and Harshness
Buzz
Buzz is a tactile rotary vibration felt in the steering wheel for slow steering inputs. Buzz can also be called a grinding feel and it is closely
related to grunt and is caused by high system gain with low damping. Buzz is generally excited during parking manoeuvres with low to
medium speed steering input.
Buzz (Electrical)
A different steering buzz can be caused by pulse width modulated (PW M) electric actuators used in variable assist steering systems. This
buzz is felt by turning the ignition key to run without starting the engine and holding onto the steering wheel. In extreme cases, the buzz
can be felt with the engine running also.
Column/Steering Wheel Shake
Column shake is a low frequency vertical vibration excited by primary engine vibrations.
Nibble (Shimmy)
Steering nibble is a rotary oscillation or vibration of the steering wheel, which can be excited at a specific vehicle speed. Nibble is driven by
wheel and tire imbalance exciting a suspension recession mode, which then translates into steering gear travel and finally steering wheel
nibble.
Shudder (Judder)
Shudder is a low frequency oscillation of the entire steering system (tire, wheels, steering gear and linkage, etc.) when the vehicle is
steered during static-park or at low speeds. Shudder is very dependent on road surface.
Torque Ripple
Torque ripple is a concern with Electric Power Steering (EPS) systems. Torque ripple is most evident at static-park steering the wheel very
slowly from lock to lock. Torque ripple is primarily caused by motor commutation.
Torque/Velocity Variation (Phasing/Effort Cycling)
Steering wheel torque variation occurring twice in one revolution is normally as a result of problems with the lower steering column
(intermediate shaft), but foul conditions generally result in either constant stiffness or single point stiffness. Depending upon the
orientation of the joints, the steering can feel asymmetric (torque falling off in one direction and rising in the other) or else it can simply
have pronounced peaks and troughs as the steering moves from lock to lock.
Wheel Fight (Kick Back)
Wheel fight is excess feedback of sudden road forces through the steering system and back to the driver. It is evaluated at all vehicle
speeds over cobblestones, rough roads, and potholes. The tires, wheels, and suspension generate forces into the steering systems.
Steering friction, hydraulic damping, hydraulic compliance, mechanical compliance, steering ratio, and assist gain all affect how much is
transmitted to the driver.
Steering Linkage
CAUTION: Steering gear boots must be handled carefully to avoid damage. Use new clamps when installing steering gear boots.
Inspect the boots for cuts, deterioration, twisting or distortion. Check the steering gear boots to make sure they are tight. Install new boots
or clamps as necessary.
• NOTE: The following steps must be carried out with assistance.
1. With the wheels in the straight ahead position, gently turn the steering wheel to the left and the right to check for free play.
1.
2. Free play should be between 0 and 6 mm (0 and 0.24 in) at the steering wheel rim. If the free play exceeds this limit, either the
2.