jeremy fisher
27-03-13, 06:46 PM
Hi, a mate at work asked me to look at his Corsa D (59 plate) because it was knocking like a biatch. I got under it and gave the wheels a shake and there seemed to be a lot of movement coming from the top mount. I was confident that was the problem but after some research I'm not so sure. Found this on a government site about MOTs
"Right, now for one from the MOT boys! When checking movement in the top strut mounts of new Vauxhall Corsa D models with the front wheels hanging free they can display quite a bit of lift, but the VSI doesn’t give any tolerances.
Why not? Well, quite simply because there aren’t any – the manufacturer doesn’t have any to give. Reason for Rejection 2.5.A.1(c) contains a note reminding testers that many of these mounts may have a degree of compliance (movement) as a design feature (just like VW Golf top mounts) and that failure is only justified when play is due to adjustment, repair or replacement being necessary.
In the case of the Corsa, the rubber mount is conical and sits in a conical seat. When the front suspension is hanging free – as a MacPherson-type suspension should be – the rubber mount can become unseated, hence the ‘lift’ when using a bar under the wheel."
It says nothing about sideways movement, but if the top mount is out of its seat surely it will be able to move?
So does anyone know what else the Knock could be? Has anyone done top mounts on a Corsa D as they look like a PITA to get at? Any other advice will be appreciated.
I know this isn't a Corsa D forum but its the only forum I'm registered on and I know there's a wealth of knowledge on here somewhere! Hopefully some of it's relevant!
Thanks
Nick
"Right, now for one from the MOT boys! When checking movement in the top strut mounts of new Vauxhall Corsa D models with the front wheels hanging free they can display quite a bit of lift, but the VSI doesn’t give any tolerances.
Why not? Well, quite simply because there aren’t any – the manufacturer doesn’t have any to give. Reason for Rejection 2.5.A.1(c) contains a note reminding testers that many of these mounts may have a degree of compliance (movement) as a design feature (just like VW Golf top mounts) and that failure is only justified when play is due to adjustment, repair or replacement being necessary.
In the case of the Corsa, the rubber mount is conical and sits in a conical seat. When the front suspension is hanging free – as a MacPherson-type suspension should be – the rubber mount can become unseated, hence the ‘lift’ when using a bar under the wheel."
It says nothing about sideways movement, but if the top mount is out of its seat surely it will be able to move?
So does anyone know what else the Knock could be? Has anyone done top mounts on a Corsa D as they look like a PITA to get at? Any other advice will be appreciated.
I know this isn't a Corsa D forum but its the only forum I'm registered on and I know there's a wealth of knowledge on here somewhere! Hopefully some of it's relevant!
Thanks
Nick