169000312 - S28 REAR SUSPENSION NOISE (KNOCK)

Whilst driving, especially on unmade roads, there is knocking coming from the rear suspension. This diagnosis can only be made after    See table S15 RUMOROSITA'' IN CONDIZIONI DI MARCIACarry out the latter first.
If the problem is only on one side, carry out the checks and any operations on the appropriate side only.
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
Having carried out the road test, during the    See table S15 RUMOROSITA' IN CONDIZIONI DI MARCIAthere was a knocking noise from the back.Continue depending on the circumstances in which the noise occurs.End of diagnosis

  • The noise disappears when the handbrake is operated
  • The noise is also present in other conditions.

  • Eliminate the handbrake lever and/or actual handbrake clearance
  • Move on to Step 1
1OIL LEAK CHECKAll OKProblems encounteredOperation
Raise the vehicle on a two column lift and check that there are no oil leaks from the shock absorber stem.
Slight dampness on the stem is considered normal because there is evaporation during the operation of the shock absorber.
If there is a persistent oil leak on the shock absorber stem, make sure that it is not coming from other parts of the vehicle that are lubricated.
Move on to Step 2

  • Leaks from other parts that are lubricated.
  • Leaks from the shock absorber stem.

2HANDBRAKE CHECKAll OKProblems encounteredOperation
Check that the handbrake cables or outer casing do not knock against the fuel tank, heat shields or bodywork during oscillations.Move on to Step 3Inteference between outer casing or cables and other elements.Cover the outer casing with foam rubber tape in the area of the interference or lubricate the cable.
3INTERFERENCE CHECKAll OKProblems encounteredOperation
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 on the suspension springs and that they do not show signs of abrasion.Check that the end of travel buffer for the rear spring is correctly inserted in its housing in the bodyshell.
If the spring shows signs of abrasion, its mechanical properties could be weakened as a result of oxidation.
Move on to Step 4

  • Inteference due to incorrect fitting.
  • Abrasions or non conformity of the spring.
  • End of travel buffer not correctly inserted

  • Eliminate the interference and restore the correct fastening. If this is not possible, replace the defective components.
  • Replace the spring    Op. 4420A48 REAR SUSPENSION COIL SPRINGS- R Rtaking care to fit it correctly
  • Replace the end of travel buffer
4TIGHTENING TORQUE CHECKAll OKProblems encounteredOperation
Locate the area of the possible noise source: top or bottom.Starting from the area where the knocking was identified, check the tightening torques See Test 4420B REAR SUSPENSION WISHBONESof the bolts fixing:

  • Shock absorber
  • Axle brackets to bodyshell
  • Axle to brackets
  • Stub axle plate
Move on to Step 5Torque tightenings not correctRestore the correct tightness
5CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsThe knocking is caused by another system (e.g. the fuel float in the tank). Carry out the appropriate checks to identify the cause of the noise.