323001380 - S028 REAR NOISE (KNOCKING)

Whilst driving, especially on unmade roads, there is knocking coming from the rear suspension. This diagnosis can only be made after    See table S015 NOISE WHILST DRIVINGCarry out the latter first.
If the problem is only on one side, carry out the checks and any operations on the appropriate side only.
Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
Having carried out the road test, during the    See table S015 NOISE WHILST DRIVINGthere was a knocking noise from the back.Continue depending on the circumstances in which the noise occurs.End of diagnosis.1. The noise disappears when the handbrake is operated.2. The noise is also present in other conditions.1. Eliminate the handbrake lever and/or actual handbrake clearance.2. Move on to Step 1.
1OIL LEAKS CHECKAll OKProblems encounteredOperation
Raise the vehicle on a two column lift and check that there are no oil leaks from the shock absorber stem.
If there is a persistent oil leak on the shock absorber stem, make sure that it is not coming from other parts that are lubricated.
Move on to Step 2.1. Leaks from other parts that are lubricated.2. Leaks from the shock absorber stem.1. Search for the cause of the leak following the appropriate diagnostic procedure.2. Replace the shock absorber.    Op. 4420A30 REAR SUSPENSION SHOCK ABSORBER (ONE), LEFT OR RIGHT - R.R. - CHECK WHEEL GEOMETRY SEPARATELY
2HANDBRAKE CHECKAll OKProblems encounteredOperation
Position the vehicle on a two column lift and raise it. 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 3.Inteference 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.Move on to Step 4.1. Inteference due to incorrect fitting.2. Abrasions or non conformity of the spring.1. Eliminate the interference and restore the correct fastening. If this is not possible, replace the defective components.2. Replace the spring    Op. 4420A48 REAR SUSPENSION COIL SPRINGS - R.R. taking care to fit it correctly.
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 4420OB CHECKS ON CORRECT TIGHTENINGS FOR REAR SUSPENSIONof the bolts:- securing the axle bracket to the bodyshell;- securing the bush to the axle bracket;- lower shock absorber fastening;- fastening the shock absorber mounting to the bodyshell.Move on to Step 5.Torque tightenings not correct.Restore the correct tightening.
5CORRECT OPERATION CHECKAll OKProblems encounteredOperation
Check that the fault is no longer present.End of diagnosis.The fault persists.The knocking is caused by another system (the fuel float in the tank, for example). Carry out appropriate checks to identify the source of the noise.