loud thud from underneath at rear

geo.k23 · 16th July 2022, 07:26

Hi all i posted this issue a couple of months back had a couple of answers back from the members i took the car to cossie dunk who replace the rear spring the rear upper arms and rear drop links that was about 4 weeks ago just yesterday when out for a drive i got a loud thump from the same area back end this does not happen on a regular basis its quite infrequent but still quite worrying is there anything else that would cause this very grateful for any input thanks in advance

Arctic · 16th July 2022, 07:30

check the drop links, anti-roll bar, and the arms, car up on ramps, or take the wheels off, could also be weak exhaust hangers.

chris75 · 16th July 2022, 11:28

Quote:

Originally Posted by Arctic

could also be weak exhaust hangers.

That's got my vote

grab the tailpipes and waggle the back box to see if you can replicate the noise

stevestrat · 16th July 2022, 12:39

Quote:

Originally Posted by chris75

That's got my vote

Mine as well. Happened with the 1.8T I used to have, exhaust had dropped just enough to bring the tunnel cross brace within range of the exhaust movement. Really solid clunk.

75driver · 16th July 2022, 17:06

Quote:

Originally Posted by stevestrat

Mine as well. Happened with the 1.8T I used to have, exhaust had dropped just enough to bring the tunnel cross brace within range of the exhaust movement. Really solid clunk.

I was listening to that “clunk” early in the week. The back box decided to separate from the rest of the exhaust.🙄
It did make a horrible clatter & clunk on start up, but all sorted now with a klarius back box.

Sent from my iPhone using Tapatalk

Atlan · 16th July 2022, 18:37

Contact the the person who did the work as by the sounds of it the work carried out hasn't cured the original problem.

bendrick · 17th July 2022, 11:06

Quote:

Originally Posted by geo.k23

Hi all i posted this issue a couple of months back had a couple of answers back from the members i took the car to cossie dunk who replace the rear spring the rear upper arms and rear drop links that was about 4 weeks ago just yesterday when out for a drive i got a loud thump from the same area back end this does not happen on a regular basis its quite infrequent but still quite worrying is there anything else that would cause this very grateful for any input thanks in advance

I had a similar occasional sound of a loud knock which got more frequent, in my case it was the exhaust hanger which over time had kind of turned to jelly and allowed the exhaust to knock against whatever it knocks against underneath the car.

New hanger problem solved overnight.

Worth checking the hanger it was really soft and flexible to the touch in my case instead of being quite firm.

DMGRS · 18th July 2022, 12:15

I had similar and oddly it was the Rear Upper Link Balls - I didn't change them as part of my Rear Upper Arm replacement (as they had no play etc) but being disturbed must have upset them.

Exhaust etc is more likely, but worth bearing in mind if you can't get to the bottom of it.

geo.k23 · 18th July 2022, 16:38

Quote:

Originally Posted by DMGRS

I had similar and oddly it was the Rear Upper Link Balls - I didn't change them as part of my Rear Upper Arm replacement (as they had no play etc) but being disturbed must have upset them.

Exhaust etc is more likely, but worth bearing in mind if you can't get to the bottom of it.

thank you all for the replies I will get to the bottom of it

StewartIngram · 18th July 2022, 19:32

The original factory fitted exhausts were one piece from front to rear; replacements seem to be in 3 sections I've found.
This leads to less rigidity in the pipework, giving just enough flex at the joint with the rear silencer to make positioning very difficult, and leads to the exhaust (straight section) banging on the cross braces across the 'transmission tunnel', or the curved joint banging on the corner where it curves up over the rear suspension etc.
I've done a modification a few times now which has been successful. No pics at the moment, but if there is interest I will take some. I'm stripping my old car for spares; having just replaced it with an identical one (same year, 03 plate), which still has the original single piece exhaust.
I acquired (ebay) a simple strap about 6" long with 2 holes in it. One is fitted to a u-bot which clamps around the exhaust joint, the other end clamps around a small u-bolt, which is fitted to the anti-roll bar. The latter u-bolt has jubilee pipe clips either side of the u-bot to help prevent it from sliding along the bar.
This makes the whole exhaust less flexible and can be adjusted for optimum clearance from the body.

16th July 2022, 07:26	#1
geo.k23 Loves to post Rover 75 Tourer CDT Join Date: Apr 2014 Location: Alexandria Posts: 463 Thanks: 451 Thanked 30 Times in 30 Posts	loud thud from underneath at rear Hi all i posted this issue a couple of months back had a couple of answers back from the members i took the car to cossie dunk who replace the rear spring the rear upper arms and rear drop links that was about 4 weeks ago just yesterday when out for a drive i got a loud thump from the same area back end this does not happen on a regular basis its quite infrequent but still quite worrying is there anything else that would cause this very grateful for any input thanks in advance

16th July 2022, 07:30	#2
Arctic Give to Learn Freelander 2 Join Date: Aug 2010 Location: West Midlands Posts: 18,708 Thanks: 1,155 Thanked 6,407 Times in 3,874 Posts	check the drop links, anti-roll bar, and the arms, car up on ramps, or take the wheels off, could also be weak exhaust hangers. __________________ Arctic Givology Learn to Give Everything is Achievable ad altiora tendo. Check out our Nano meet dates http://www.midlandsnanomeets.co.uk/ http://www.the75andztclub.co.uk/index.php?thepage=howto " You do the work , we supply the expertise "

16th July 2022, 18:37	#6
Atlan Avid contributor rover 75 Join Date: May 2016 Location: Home Posts: 203 Thanks: 6 Thanked 99 Times in 70 Posts	Contact the the person who did the work as by the sounds of it the work carried out hasn't cured the original problem. __________________ Illegitimi non carborundum

18th July 2022, 12:15	#8
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	I had similar and oddly it was the Rear Upper Link Balls - I didn't change them as part of my Rear Upper Arm replacement (as they had no play etc) but being disturbed must have upset them. Exhaust etc is more likely, but worth bearing in mind if you can't get to the bottom of it. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

18th July 2022, 19:32	#10
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 902 Thanks: 320 Thanked 159 Times in 127 Posts	The original factory fitted exhausts were one piece from front to rear; replacements seem to be in 3 sections I've found. This leads to less rigidity in the pipework, giving just enough flex at the joint with the rear silencer to make positioning very difficult, and leads to the exhaust (straight section) banging on the cross braces across the 'transmission tunnel', or the curved joint banging on the corner where it curves up over the rear suspension etc. I've done a modification a few times now which has been successful. No pics at the moment, but if there is interest I will take some. I'm stripping my old car for spares; having just replaced it with an identical one (same year, 03 plate), which still has the original single piece exhaust. I acquired (ebay) a simple strap about 6" long with 2 holes in it. One is fitted to a u-bot which clamps around the exhaust joint, the other end clamps around a small u-bolt, which is fitted to the anti-roll bar. The latter u-bolt has jubilee pipe clips either side of the u-bot to help prevent it from sliding along the bar. This makes the whole exhaust less flexible and can be adjusted for optimum clearance from the body.