198003020 - 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
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Having carried out the road test    See table S015 NOISE WHILST DRIVINGa knocking noise is noticed at the back.Continue depending on the situation when the noise appears.	End of diagnosis	1. The noise disappears when the handbrake is operated2. The noise is also present in other conditions.	1. Eliminate the handbrake lever and/or actual handbrake clearance2. Move on to Step 1
1	FLUID LEAKS CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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	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 procedure2. Replace the shock absorber    Op. 4420A30 REAR SUSPENSION SHOCK ABSORBER (ONE), LEFT OR RIGHT - R.R. - CHECK WHEEL GEOMETRY SEPARATELY
2	HANDBRAKE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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.
3	INTERFERENCE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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. If the spring shows signs of abrasion, its mechanical properties could be weakened as a result of oxidation.	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
4	TIGHTENING TORQUE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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 fixing:- the axle brackets to the bodyshell;- the torsion beam bushes to the axle mounting brackets;- the lower shock absorber eyelet;- the upper shock absorber mounting;- the rear brake caliper to the stub axle.	Move on to Step 5	Torque tightenings not correct.	Restore the correct tightening.
5	CORRECT OPERATION CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	The fault persists.	The 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.