Noises heard when steering - AF46.00-P-1000AG

MODELS 168, 203, 209, 210, 211, 215, 220, 230, 414 

Damage code	Cause	Remedy
	Information from customer:	Have the noise described in detail by the customer and understand it!
	Noises are difficult to locate and can often only be reproduced some of the time. It is therefore essential that the customer gives a precise description of the noise and if possible also demonstrates when and how the noise can be heard.	For which steering condition/process is the noise complained of and how does it make itself noticeable?
	If the noise cannot be reproduced, discuss further procedures with the customer.	Does the noise occur when stationary/ parking and/or when driving (which driving conditions, speed, road surface condition)? Does the noise occur permanently or only at times? Is the noise heard when the engine is cold or warm?
	Carry out general test/evaluation of noises heard in steering system:	Check whether the steering noise can be reproduced.
		2 Check whether the customer is complaining about the current production configuration. Take comparable vehicle if necessary.
		3 Check whether noise occurs in warm or cold state.
		4 Check whether the noise is the same in left-hand drive vehicles and right-hand drive vehicles.
		5 Check exactly when the sound can be heard. When the vehicle is stationary/parked and/ or when driving.
		6 Check whether the noise can only be heard in combination with certain steering wheel positions/ angles or over the entire steering angle range.
		7 Check whether the noise is produced together with mechanical feedback felt at the steering wheel. Vibrations, actuation point, sticking, slightly jamming, etc.
		8 Check whether the noise is caused by play in the steering system.
		If yes, follow steps for dealing with play in steering system.	AF46.00-P-3002A
		9 Check whether noise can be reproduced on the lifting platform. Can the noise also be heard when the wheels are relieved of load or only when the wheels bear the weight of the vehicle?
		10 Check whether noise can be localized by feeling with finger or stethoscope.
		If the noise can be reproduced, assign the noise to one of the following categories: Squeak (rubber noise) Grinding noise Hydraulic noise: hissing/whistling noise Honking noise Humming/grunting Cracking noise Knocking/rattling
	Specific test:  ↓ Squeaking noise (squeaking rubber)	Determine whether the noise comes from the interior compartment of the vehicle or outside this area.
	Squeaking noises are usually temperature-dependent since they are caused by the friction of plastic or rubber parts and the amount of friction changes according to the temperature.	2 Check whether the noise is temperature- dependent. At what operating temperature or outside temperature does the noise occur?
		3 Check whether the noise comes from the jacket tube boot (check using your fingers).
		4 Check whether interior compartment and engine compartment sides of boot are sufficiently lubricated. Remove the boot if necessary and check to see if the noise can be heard when the boot has been removed.
		5 Check whether the noise changes when the steering wheel is moved to different positions (position of steering column). Can the noise only be reproduced when the engine is running or also without power assistance?
	Specific test:  ↓ Grinding noise	Check whether noise comes from interior compartment or from outside area.
		2 Check which part is grinding. Trim, floor sound deadening mat, clock spring contact, steering wheel, steering shaft, tie rods.
		3 Check whether the noise changes when the steering wheel is moved to different positions (position of steering column).
		4 Can the noise only be reproduced when the engine is running or also without power assistance?
		5 Check in center position whether the side bellows of the steering are S-shaped.
		If yes: ↓ Check whether the noises can be heard when the steering is moved, as the bellows move over the inner axial joint.
	Specific test:  ↓ Hydraulic noises	Check whether the noise is dependent on the operating temperature.
	Hydraulic noises can be heard in the hydraulic circuit (pump, hoses, steering gear) and often only occur during certain steering procedures associated with other parameters such as temperature and engine speed.	Cold/warm?
	Hissing/whistling sound:  ↓ A hissing/whistling sound is a quiet noise that is usually caused by rough edges or foreign matter in the hydraulic circuit.	2 Check whether the noise changes as the engine speed changes.
		3 Check whether the noise is the same when the steering wheel is turned in both directions or if the noise is only produced when the steering wheel is turned in one direction.
		4 Check whether the noise occurs before the steering wheel is turned (continuous flow), when the steering wheel is turned slightly and held in this position (without turning the wheels), or if the noise occurs during actual steering procedures (wheels are turned).
	Honking noise:  ↓ A honking noise is a clear and relatively loud noise that usually only occurs briefly when parking. This noise is the sound of the steering valve vibrating. It is dependent on the steering oil temperature and the steering speed.	Check at what operating temperature the noise occurs.
		2 Check whether the noise is dependent on the engine speed.
		3 During which steering movements does the noise occur? When turning in or turning back? Left/right
		4 Check whether the noise is dependent on the steering speed. Turning the steering wheel quickly or slowly.
		5 Check whether the noise can be heard when the wheels are relieved of the weight of the vehicle.
	Humming/grunting noise:  ↓	Check whether the oil level in the reservoir is OK.
	A humming noise is a rather deep noise that is often heard in connection with vibrations felt at the steering wheel and usually occurs when air enters the steering system (oil level too low or when bleeding the steering system after carrying out repair work).	Is the oil foaming? Is the oil moving around in the reservoir?
	Humming noises and vibrations in the steering system can also be due to operation irregularities caused by the engine and fluctuations in engine speed. Ensure, therefore, that the engine operation is OK before carrying out any tests.	2 Check whether the hydraulic lines are exposed or are touching other components.
		Check while moving the steering wheel since all hoses can move.
		3 Check whether the noise is dependent on the operating temperature.
		4 Check whether the noise changes as the engine speed changes.
		5 Check whether the sound is the same when steering in both directions.
		6 During which steering procedures does the noise occur? At the limit stop or when moving the steering wheel near the center position. Steering noises shortly before and at the steering stop are normal and are not a cause for complaint. The maximum pressure in the system is applied at these steering wheel positions and this inevitably produces noises.
	Cracking noise:  ↓ A cracking noise can be heard above all when steering when the vehicle is stationary or during parking maneuvers, and there is a direct correlation between the noise and the movement of the steering wheel. An assessment must only be made when the engine is running.	Check whether the cracking noise occurs when continuously steering in one direction or whether the noise always occurs when changing the steering direction (changing from steering right to steering left, and vice versa -> cracking noise when changing the steering direction).
	Note that a certain amount of radial play is required in the steering gear and if the vehicle is stationary, this play can be heard to a small extent when changing from steering right to steering left, and vice versa. This sound is related to the design of the steering system and is not a cause for complaint.	If the cracking noise occurs when changing the steering direction: ↓
	A cracking noise is a mechanical sound and is usually caused by play.	2 Carry out assessment using a comparable vehicle.
		3 Check whether the cracking noise always occurs in same steering wheel position/ angle.
		4 Check whether cracking noise occurs predominantly in the center position or more towards the limit stop.
		5 Check whether the noise is temperature- dependent. If yes, how? Operating temperature or outside temperature.
		6 Check that all threaded connections are screwed tight (steering coupling, jacket tube, steering gear, reinforcement braces).
		7 Check whether there is play at any point.	AF46.00-P-3002A
		8 Check steering coupling in vise for play.
		9 Check tie rod joints for play.
	Rattling/knocking noise:  ↓ A rattling/knocking noise only occurs when driving and is caused by the condition of the road/terrain (road surface, pot holes, etc.).	Check whether the rattling/knocking noise is influenced by steering or if it occurs independently of any steering procedures.
	Note that the rattling/knocking noise may be caused by many other reasons not associated with the steering system, which must also be checked.	The noise could be caused by another axle component.
		2 Under which driving conditions (speed, accelerating/decelerating) and on which kind of road/terrain (kind of road surface, pot holes) does the rattling/knocking noise occur?
		3 Check whether the noise occurs predominantly in the center position or when the steering wheel is turned.
		4 Check whether the noise is temperature- dependent. If yes, how? Operating temperature or outside temperature.
		5 Check that all threaded connections are screwed tight (steering coupling, jacket tube, steering gear).
		6 Check play of jacket tube, steering coupling, steering gear, check tie rods.
	Cause 1:	Remedy 1:
	Oil reservoir	Remove/install/replace oil reservoir
	If the filter in the oil reservoir is defective and the oil retuning to the reservoir is not settled sufficiently, the oil can foam even though the oil level is correct, and cause a humming/grunting noise. This is identifiable by a clear signs of a current/whirling motion in the oil in the oil reservoir when the engine is running.	If then part can be replaced separately. Otherwise remove/install/replace pump with oil reservoir.
	Cause 2:	Remedy 2:
	High pressure hose	Remove/install/replace high pressure hose.
	In addition to conducting the hydraulic oil, high pressure steering hoses serve to reduce vibration from the engine and power steering pump to prevent vibration and noise at the steering wheel. The high pressure hose may be the cause if hissing noises can be heard when steering in both directions and the hissing noise occurs independently of the engine speed. The high pressure hose may be the cause if humming noises, possibly together with vibrations, occur when steering in both directions, (please contact workshop service).
	Cause 3:	Remedy 3:
	Steering coupling	If play is detectable: ↓
	If cracking noises occur when changing the steering direction or if rattling/knocking occurs when driving on rough roads, the steering coupling may be the cause, in which case play must be detectable at the universal joint.	Remove/install/replace steering coupling.
	Cause 4:	Remedy 4:
	Jacket tube boot	Grease boot at slide surfaces.
	A squeaking noise (squeaking rubber) is often caused by the boot.	At engine side and inside vehicle, boot for steering shaft and if necessary also outer side (model 220). (Grease A001 989 84 51 10, Klueber NCA 152 acc. to DBL 6834.10).	*BR00.45-Z-1046-06A
		2 Ensure jacket tube boot is seated correctly and adjust if necessary.
	Cause 5:	Remedy 5:
	Trim/clock spring contact A grinding noise coming from the interior compartment is usually caused by a trim or the clock spring contact grinding against another part, whereby the noise occurs independently of whether the engine is running, but is often related to a certain steering wheel position.	Locate and eliminate noises.
	Cause 6:	Remedy 6:
	Jacket tube/steering shaft	Cracking noises caused in the steering column are usually the result of play.	AF46.00-P-3002A
	A cracking sound occurs when actuating the longitudinal adjustment of the electric steering column because of the design and is not a cause for complaint.	Cracking noises may also be caused by a damaged steering shaft bearing. If this is the case, chatter marks can be felt when the steering shaft is turned: ↓ Repair steering shaft bearing.
		If the steering shaft bearing cannot be repaired: ↓ 2 Remove/install, replacing jacket tube
	Cause 7:	Remedy 7:
	Power steering pump	The following test results must be available before the power steering pump can be identified as the source of the noises:
	The power steering pump is a possible cause for humming/grunting noises.	Oil level is OK. The oil does not foam or does not show any significant vortex. There is a direct dependency of noise on engine speed.
	The power steering pump may be responsible for a hissing noise if the noise is the same when the steering wheel is turned to the left and the right and if the noise is dependent on the engine speed.	If these test results are obtained, the power steering pump seems to be causing the noises reported by the customer: ↓
	Hissing noises at the limit stop are normal.	Remove/install/replace power steering pump
	Cause 8:	Remedy 8:
	Steering gear	Squeaking noises  may be caused by the steering gear, provided that the jacket tube boot and surrounding area and the suspension strut bearing have been eliminated as possible causes. 1.1 Remove/install/replace steering gear, models 168, 211, 215, 220, 230.
		1.2 Replace bottom radial shaft sealing ring on steering housing.
		Model 203, 209	AF46.20-P-1100BG
		Model 210	AF46.20-P-1100AG
	The other possibilities must be checked before the steering gear can be considered as a possible source of the noise.	Grinding noises  are rarely caused by a problem with the steering gear. The steering gear must only be considered as a possible cause if the noise has been located as originating in the engine compartment and all other causes have been eliminated. S-shaped bellows can be replaced separately. Remove/install/replace steering gear.
		It can be safely assumed that a hissing/whistling noise  is caused by the steering gear if the noise only occurs when steering in one direction (i.e. just when steering to the left or right). If the hissing/whistling sound can be heard when steering in both directions and the high pressure line has been eliminated as a possible cause: ↓ Locate with stethoscope.
		2 If the vehicle is equipped with speed- sensitive power steering, try detaching the connector from the parameter valve and listen to see if the noise changes. If the noise disappears then install a new parameter valve.	AF46.50-P-3600A
		3 Remove/install/replace steering gear.
		A honking noise  can be heard in the control valve of the steering gear: ↓ 4 Contact the workshop service, a modified hose variant is available if required.
		Humming/grunting noises  do not occur as a result of problems in the steering gear but are usually caused by other reasons.
		Cracking noises  that can be heard when changing the steering direction may originate from the steering gear if there is excessive play at the thrust piece. Radial play in the steering gear and therefore a slight noise when changing the steering direction is caused by the design of the steering system and is not a cause for complaint. All other possible causes (steering coupling, steering column) must be checked before installing a new steering system. Check thrust piece play and adjust if necessary.
		Ratting/knocking noises  can only be assumed to be caused by play in the steering gear if all other possible causes have been eliminated. Check thrust piece play and adjust if necessary.