Knocking and a-clunking

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ScimiTom
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Knocking and a-clunking

Post by ScimiTom » Tue Sep 04, 2018 9:17 pm

I'm looking for any suggestions as to what may be causing the following symptom on my SE5a.

On any sharp right turn, there are a few dull clunks/knocks from somewhere around the offside front wheel area. It is most noticeable when I start to straighten up the wheel. It feels like it should be the steering column, but I've been under the front end and the springs/trunnions/steering column/boots etc all looked intact. When giving the car a good 'shoogle', everything sounded solid.

The symptom has been there for months now. It's not getting noticeably worse but is increasingly irritating. It began around about the time I smacked a whopping great pot-hole on an otherwise flawless road surface (with my offside front wheel) at around 50mph.

Any ideas where the noise could be coming from? Thanks...

Tom


Current: 'Boffin' (1971 SE5a)
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peter freeman
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Knocking and a-clunking

Post by peter freeman » Tue Sep 04, 2018 10:14 pm

Have you checked the wishbone bushes and brackets



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Will Anderson
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Knocking and a-clunking

Post by Will Anderson » Tue Sep 04, 2018 10:21 pm

peter freeman wrote:
Tue Sep 04, 2018 10:14 pm
Have you checked the wishbone bushes and brackets
My initial thought too, if the springs are intact. Lower rear bracket would be the first I would check.


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Knocking and a-clunking

Post by Oxymoron » Wed Sep 05, 2018 9:07 am

You need to jack the front end up and move the suspension and steering around when not under load.

Sounds like worn bushes or ball joints?

I have been getting a similar noise when initially negotiating roundabouts whilst steering to the right...Has occurred since Scimfest after following my Sat nav through a housing estate on the edge of Lichfield which had dozens of speed humps!


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Knocking and a-clunking

Post by b.c.flat hat » Wed Sep 05, 2018 12:55 pm

Just my 2d worth, top and bottom damper bushes squished resulting in metal to metal contact on the mounting brackets.



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Knocking and a-clunking

Post by Alan SS1 » Thu Sep 06, 2018 12:40 pm

loose shock absorber bolt, (been there :oops: )


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Knocking and a-clunking

Post by ScimiTom » Sun Oct 28, 2018 8:25 pm

Thanks for the suggestions everyone. All good ideas, but it turned out to be something else...

The offside exhaust downpipe is knocking against a 'triangular' bracket on the chassis. I shaped a 3mm thick lead sheet and inserted it snugly into the gap, which cured the knocking. But at some point it has fallen out, so the knocking is back!

Does anyone have a more sophisticated (and long-term) solution? Or any ideas as to what has caused the exhaust pipe to get so close to the chassis at that point? I'm starting to worry about engine mounts now... :(


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Knocking and a-clunking

Post by peter freeman » Sun Oct 28, 2018 8:29 pm

Check the engine is square on the chassis - a bit too low on one side will put the other side too high - been there had that. Easy to put right by adjusting the engine mounts.



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Knocking and a-clunking

Post by efi_sprintgte » Sun Oct 28, 2018 8:33 pm

ScimiTom wrote:
Sun Oct 28, 2018 8:25 pm

The offside exhaust downpipe is knocking against a 'triangular' bracket on the chassis. I shaped a 3mm thick lead sheet and inserted it snugly into the gap, which cured the knocking. But at some point it has fallen out, so the knocking is back!

Does anyone have a more sophisticated (and long-term) solution? Or any ideas as to what has caused the exhaust pipe to get so close to the chassis at that point? I'm starting to worry about engine mounts now... :(


Is it tubular manifolds or the cast iron with a single down pipe?

I would be looking at engine, gbox and exhaust mounts.


JC

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Knocking and a-clunking

Post by ScimiTom » Sun Oct 28, 2018 8:45 pm

Thanks, guys. Here's the area in question...
IMG_4588.JPG
IMG_4588.JPG (125.81 KiB) Viewed 1160 times

Can the mounts be checked and adjusted with everything 'in situ', or is it a case of an engine lift first?


Current: 'Boffin' (1971 SE5a)
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Knocking and a-clunking

Post by peter freeman » Sun Oct 28, 2018 8:47 pm

slacken the mounts and adjust with a hammer - metal at either end so you will not damage them.



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Knocking and a-clunking

Post by Coupe Racing » Sun Oct 28, 2018 8:59 pm

It could be the relationship between the manifold and downpipe on a curve flange socket which will allow it to be tightened or set in a variety of positions and you can get some contact on an outrigger that already has limited clearance


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Knocking and a-clunking

Post by ScimiTom » Thu Aug 15, 2019 10:44 pm

Just to provide some 'closure' on this one... The 'knocking exhaust downpipe' turned out to be a bit of a red herring. Yes, it was partially to blame for the clunking, and repositioning it has helped. But in the end the culprits were (as many of you initially suggested) the upper wishbone bush mounts and the lower trunnion mounting bolt (which was totally seized up). After some freeing up with Copperslip, and some reassembly, all unwelcome noises have (for the timebeing) disappeared! :)


Current: 'Boffin' (1971 SE5a)
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Dennis Nicholas
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Knocking and a-clunking

Post by Dennis Nicholas » Sat Aug 17, 2019 1:06 pm

Copperslip is abrasive. Grease with MOLY better on trunnion bushes and of course grease nipples on wishbone outer ends. CV joint grease with moly.


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