192005533 - S018 FRONT SUSPENSION NOISE (KNOCKING)

Whilst driving, especially on unmade roads, there is knocking coming from the front suspension. This fault diagnosis can only be carried out after the     See table S015 VEHICLE RUNNING NOISE . Carry out the latter first.
If the problem is only on one side, carry out the checks and any necessary operations on the appropriate side only
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Having carried out the road test during the See table    S15 RUMOROSITA'' in condizioni di marcia, a knocking noise is heard coming from the front.Continue depending on the circumstances in which the noise occursEnd of diagnosisThe noise disappears when the brake pedal is operatedCheck the clearance for the front brake calipers and lubricate the wheel bolt pins
The noise disappears when the brake pedal is operatedReplace the wheel bearing on the side that the problem occurs Op.    4450C32 , positioning it with the magnetic race towards the vehicle exteriorWarning: This bearing is used by the ABS active sensors to calculate the wheel speed. It should NEVER come into contact with metal shavings because this could adversely affect the gap and prevent the sensor giving a correct reading
The noise disappears when the brake pedal is operatedContinue to Step 1
1CHECK FOR OIL LEAKSAll OKProblems metOperation
Raise the vehicle on a two collumn lift and check that there are no oil leaks from the shock absorber stem
Slight dampness of the stem is considered normal because there is evaporation that takes place during the operation of the shock absorber. If there is a consistent oil leak at the shock absorber stem, make sure that it is not coming from other parts of the vehicle that are lubricated
Continue to Step 2Leaks from other parts that are lubricatedSearch for the cause of the leak by following the appropriate diagnostic procedure
Leaks from the shock absorber stemReplace the shock absorber Op.    4410A10 )
2INTERFERENCE CHECKAll OKProblems metOperation
Check that there are no signs of interference between the suspension elements or between the latter and the bodyshell.In particular, check that there are no signs of wear at the suspension springs and that they do not suffer from abrasions
If the spring shows signs of abrasions, its mechanical properties could be adversely affected as a result of oxidation
Continue to Step 3Interference due to incorrect fittingEliminate the interference and restore the correct fastening If this is not possible, replace the defective components
Abrasions or non conformity of the springReplace the spring Op.    4410A12 taking care to fit it correctly
3TRACK CONTROL ARM CHECKAll OKProblems metOperation
Check that there is no clearance between the track control rod ends and that the bush is intactTo do this it it necessary to remove the guard under the engine Op.    7055B54 , then loosen the bolt connecting the track control arm to the front steering knuckleAlso check the condition of the suspension bushesContinue to Step 4There is clearance or the boot or bushes are not intactReplace the track control arm Op.    4410B40
4TIGHTENING TORQUE CHECKAll OKProblems metOperation
Locate the area that is the possible source of the noise: top or bottom.Starting from the area where the knocking was located, check See Test    4410A Verifiche corretti serraggi sospensioni anteriori

The tightening torques of the bolts fixing the:

  • Mountings
  • Bushes
  • Track control arms
  • Steering knuckles
  • Anti-roll bar
Continue to Step 5Tightenings not to torqueRestore the correct tightening
5SHOCK ABSORBER FASTENING CHECKSAll OKProblems metOperation
Check that there is no clearance between the shock absorber mounting bearing and the rubber mounting and that the bearing is fitted in the correct direction, by carrying out the See Test    4410AB Verifica tassello in gomma e cuscinetto su ammortizzatore anterioreContinue to Step 6There is clearance in the bearingReplace the bearing
The bearing is fitted in the wrong directionIf the bearing is not damaged, fit it correctly. If this is not the case, replace it.
6Continue as instructed by the testerAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsThe fault is due to another system (engine, clutch, differential). Search for the cause in one of these systems, following the appropriate diagnostic procedures