194002065 - S027 REAR NOISE (WHISTLING/HUMMING)

Whilst driving, especially on unmade roads, there is a whistling noise coming from the rear suspension. This diagnosis can only be made after     See table S015 NOISE WHILST DRIVING . Carry 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	Operation
	Having carried out the road test, see the Table    S15 RUMOROSITA'' in condizioni di marcia, there was a whistling noise from the back.Continue depending on the circumstances in which the noise occurs	End of diagnosis	The noise increases when cornering	Replace the wheel bearing complete with hub on the side where the noise is loudest
			The noise increases in vertical oscillation conditions	Move on to Step 1
1	CHECKS ON THE WHEEL HUB	All OK	Problems encountered	Operation
	Visually inspect that the yield point type bolts fixing the bearing to the steering knuckle have not loosened.	Move on to Step 2	Yield point type tightenings loosened	Replace the yield point type bolts
2	BRAKE DISC CHECK	All OK	Problems encountered	Operation
	Check for any distortion to the disc heat shield.Also check for the onset of noise due to contact between the disc and the heat shield by rotating the wheel assembly	Move on to Step 3	Distortion of the heat shield	Restore the correct gap    Op. 3310B59 REAR BRAKE DISC GUARD (ONE), LEFT OR RIGHT - R.R./replace the shield    Op. 3310B59 REAR BRAKE DISC GUARD (ONE), LEFT OR RIGHT - R.R.
			Contact between heat shield and disc	Replacement of brake disc    Op. 3310B48 REAR BRAKE DISC (ONE), LEFT OR RIGHT - R.R.if the noise persists, replace the wheel bearing complete with hub    Op. 4450D10 HUB FOR ONE REAR WHEEL, L/H OR R/H - R+R WITH WHEEL REMOVED - CHECK WHEEL GEOMETRY SEPARATELY
3	SHOCK ABSORBER STEM CHECK	All OK	Problems encountered	Operation
	Remove the left wheel    Op. 4450B06 LEFT REAR WHEEL - R.Rand/or the right one    Op. 4450B08 RIGHT REAR WHEEL - R.RCheck that the noise is not due to irregular friction between the shock absorber stem and the gasket, checking the condition of the stem chrome surface.	End of diagnosis	There is irregular friction	Lubricate the stem raising the dust cover with a layer of silicon grease. If the noise persists, replace the shock absorber    Op. 4420A30 REAR SUSPENSION SHOCK ABSORBER (ONE), LEFT OR RIGHT - R.R. - CHECK WHEEL GEOMETRY SEPARATELY