Suspension: - Intermittent knocking

glengibson · Jan 12th, 2020, 16:36

Hi all !
I have an intermittent knocking coming from front suspension. Seems to be worse under slow speed braking. I’ve recently replace both front/rear vacuum mounts and installed poly subframe inserts so it’s not those mounts. Doesn’t seem to be any worse on corners.
Any input on this is appreciated. Thanks

owenfackrell · Jan 13th, 2020, 21:06

Have you checked the drop links as these can cause knocking also its worth jacking each side up and trying to shake the wheel to check the steering components.

oragex · Jan 13th, 2020, 21:26

Good to check the wheel lugs. These would cause repeated knocking under braking. Otherwise, maybe the brackets on the rear subframe mounts, their 14mm bolts not tight enough ?

In summer time I also get knocking from the anti roll to subframe bushes

Littlereggie646 · Jul 22nd, 2020, 19:09

Hi All, I have exactly the same issue. I have owned my Volvo XC90 for 2 years - it is 2013 model with 93k miles.

I have recently had to replace the two front wishbones, bushes and two new drive shafts. Very expensive.

The knocking from the front, when braking - can be caused by brakes themselves apparently. It has something to do with the Pads being loose - or jumping up on a raised rim of the disc and then dropping back down.

Mine knocks whenever I am in stop start traffic - always when braking.

This issue seems very common - but I am not certain what the issue is.

Danielpsmith · Jul 22nd, 2020, 19:50

I had the same issue a couple of years ago and it was the brake pads, I changed them and all was fine.

The pads were genuine Volvo and we’re only 14 months old when this happened and no idea why but new pads sorted it.

Tannaton · Jul 22nd, 2020, 22:24

Find some speed bumps (and there are loads in Hull................)

If you drive over a mound that doesn't go across the full width of the road in a way that one wheel goes over the bump - see if it knocks.

Then drive over a hump that goes over the full width of the road.

If you are more likely to get a knock on test 1 - check anti roll bar drop links and mounting bushes.

If both or test 2 - check ball joints, track rod ends, and strut top mounts on the relevant sides. First check on the strut top mounts is does one rest higher than the other?

If you get the knock predominantly on braking (and acceleration) then check wishbone bushes and subframe bolts are torqued.

Jan 12th, 2020, 16:36	#1
glengibson Member Last Online: Apr 16th, 2024 22:36 Join Date: Jan 2008 Location: Hull	Intermittent knocking Hi all ! I have an intermittent knocking coming from front suspension. Seems to be worse under slow speed braking. I’ve recently replace both front/rear vacuum mounts and installed poly subframe inserts so it’s not those mounts. Doesn’t seem to be any worse on corners. Any input on this is appreciated. Thanks

Jan 13th, 2020, 21:26	#3
oragex Premier Member Last Online: Jul 26th, 2021 21:24 Join Date: Jun 2013 Location: Coldnada	Good to check the wheel lugs. These would cause repeated knocking under braking. Otherwise, maybe the brackets on the rear subframe mounts, their 14mm bolts not tight enough ? In summer time I also get knocking from the anti roll to subframe bushes __________________ Several Volvo Repair Videos https://www.youtube.com/playlist?lis...ECTts0FSVSOT_c

Jul 22nd, 2020, 19:09	#4
Littlereggie646 New Member Last Online: Jul 30th, 2020 14:56 Join Date: Jul 2020 Location: Bristol	Knocking Hi All, I have exactly the same issue. I have owned my Volvo XC90 for 2 years - it is 2013 model with 93k miles. I have recently had to replace the two front wishbones, bushes and two new drive shafts. Very expensive. The knocking from the front, when braking - can be caused by brakes themselves apparently. It has something to do with the Pads being loose - or jumping up on a raised rim of the disc and then dropping back down. Mine knocks whenever I am in stop start traffic - always when braking. This issue seems very common - but I am not certain what the issue is.

Jul 22nd, 2020, 22:24	#6
Tannaton Bungling Amateur Last Online: Today 08:59 Join Date: Aug 2014 Location: Beverley, East Yorks	Find some speed bumps (and there are loads in Hull................) If you drive over a mound that doesn't go across the full width of the road in a way that one wheel goes over the bump - see if it knocks. Then drive over a hump that goes over the full width of the road. If you are more likely to get a knock on test 1 - check anti roll bar drop links and mounting bushes. If both or test 2 - check ball joints, track rod ends, and strut top mounts on the relevant sides. First check on the strut top mounts is does one rest higher than the other? If you get the knock predominantly on braking (and acceleration) then check wishbone bushes and subframe bolts are torqued. __________________ 2011 XC90 D5 Executive 2003 C70 T5 GT 2012 Ford Ranger XL SC 1977 Triumph Spitfire 1500 1976 Massey Ferguson 135

Jan 13th, 2020, 21:06	#2
owenfackrell Premier Member Last Online: Feb 4th, 2024 19:04 Join Date: Dec 2009 Location: southampton	Have you checked the drop links as these can cause knocking also its worth jacking each side up and trying to shake the wheel to check the steering components.

Jul 22nd, 2020, 19:50	#5
Danielpsmith Master Member Last Online: Apr 23rd, 2024 11:11 Join Date: Apr 2013 Location: Birmingham	I had the same issue a couple of years ago and it was the brake pads, I changed them and all was fine. The pads were genuine Volvo and we’re only 14 months old when this happened and no idea why but new pads sorted it.

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