Dunk -clunk from ZX rear suspension

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NiSk
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Joined: 24 Jan 2002, 20:11
Location: Sweden
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Dunk -clunk from ZX rear suspension

Post by NiSk »

Yep - daughters '94 Aura 1.8, makes a dull resonating clunk when driving over potholes - really gives a big bang when crossing level crossings fast. Having looked under it over a grease pit, I can't find anything obviously loose (exhaust, spare wheel, jack, etc). A crow bar between the front rubber subframe mounts gives a similar, but much lower sound. The subframe itself is in first class condition.
I was hedging on it being the front subframe bushes, but a mechanic I know said that a common fault on the Pug 306 is the needle bearings in the torsion bar tube, but how does one make sure before pulling it all apart?
//NiSk
Gaskin
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Post by Gaskin »

I don't know about bearings, but it sounds like subframe mounts. If the rear ones are really bad when you jack the car up the subframe hangs off !! It's a bit frightening when you see it. Mine went between MOT's.
Change all 4 at the same time otherwise you only have to go back later and do it properly (so I'm told!?!). I've done mine on an estate on my own, but if you can borrow a friend it is much easier.
The other possibility is a loose tailgate, which gives a similar sound to the knackered subframe mounts.
Unless you know the mounts are new I'd change them anyway if only for peace of mind. Others with more experience should be able to help with bearing symptoms.
Cheers
Duncan
NiSk
Posts: 1422
Joined: 24 Jan 2002, 20:11
Location: Sweden
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Post by NiSk »

Yes, I did notice that the tailgate made the same sort of noise and the hinges seem rather loose when the rear door is open, but I can't reproduce the sound with the tailgate closed. Since no one else seems to have heard about needle bearings in the torsion tube, I guess I'll change the rubber subframe mounts first and see what happens . . .
//NiSk
Dave Burns
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Post by Dave Burns »

To check for play or roughness in the bearings, jack the car up and support, remove the wheel and unbolt the damper on the offending side to allow the arm to rest unsprung, it is now easey to detect any play in the arm shaft.
To check for knocking in the rear subframe front mouinting, jack the rear of car up and support it by the vehicle jacking points on the sill, not via the axle cross tube as this will keep the mountings loaded and wont allow them to flex, then get a lever under the rear wheels and a fulcrum point along the lever so that when you stand on the lever the wheel will rise slightly, now stamp on the lever and let it go sharply, if the mounting is bad you will deffinately hear it knock as the subframe flexes downwards on its mountings.
Dave
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