Strange banging/clanking sound. Help ?

[tomtom]

Hi all,
My car has developed (1 day ago) a metalic rattling/banging/clunking sound when I begin de accelerating with my foot off the clutch. When I put my foot down on the clutch the banging stops. The noise starts as soon a i take my foot off the accelerator and only at low speeds (10-20mph). Is its the prop shaft? Or dif?

Thanks in advance..

[bmcecosse]

First check - are all the wheel nuts TIGHT? Then indeed have a look at the prop shaft - I doubt it will be the 'diff' but it is possibly something in the final drive........ Check to see if the rear axle locations have rusted away - allowing the axle to twist round on the rear springs......

[tomtom]

Thanks for the reply! All wheel nuts are tight, diff seems fine - have just replaced the oil in it. The rear axle locations are fine we are totally stumped! There is some 'play' in the propshaft e.g. can twist it slightly by hand... but this has always been like this and the noise has only just developed...

Thanks

[bmcecosse]

There is always some twist in the drive. Check the rear springs are ok - and take the rubber bungs out of the clutch bell housing and look inside - bright light in one and eye to the other. Don't do this with engine running - but maybe get someone to gently turn the engine over on the handle.

[tomtom]

Right thats ok then.. The rear springs are all good. I will check the clutch, but it does not make the noise when stationary anyway.. However it could be something with the clutch as lately it feels as if (when im changing gear) that i have to push it into gear with some very slight resistance, I think.. well know that the clutch is worn but could this be creating the loose rattling/ banging noise prehaps??

[bmcecosse]

So if you put it in gear - is there any noise? Or does it only start when you actually move away from rest?

[David W.]

Can I assume the noise varies with road speed rather than engine speed?

[bmcecosse]

Sounds like exhaust hitting the body now I read the post again!

[tomtom]

It happens intermittently, sometimes just after its been put in gear and also when im slowing down (say second gear) without the clutch down (when the clutch is down the noise stops).I would say that the noise varies with road speed. However it makes the same noise when going over speed bumps ( I dont know if its the bump or the fact that i have changed gear or slowing down). It does sound like a metal/tube noise but i have checked the exhaust by grabbing it and trying to shake it, it seems ok.

[AndrewSkinner]

How about the clutch shaft? The one that sits between the gearbox and chassis leg that holds the clutch pedal? Isnt there meant to be a fabric washer there to keep it quiet? I know that mine makes a nasty rattle sometimes if the engine idles lumpy.

A tired gearbox mount, over tight gearbox steady cable or worn shaft/fabric washer could make this noise on yours? Just like you the noise on mine will go away If you depress the clutch pedal as you put pressure on it.

Is it only under load? Could you very carefully put it into gear with the rear on axle stands and then get a better listen for the noise? I probably wouldn't go under it still

[tomtom]

It's not under load. Well next week am going to replace the engine and clutch so I will be able to have a look at the clutch ect. I am expecting a small piece of something to drop out when I take it apart because that's what it sounds like... I will report back with what I find ...

[David W.]

Sounds a bit like what I'm experiencing. Check the torque on your flywheel bolts. Mine were not torqued (40 ft. lbs).
It'll still be a few weeks before I'm back together, so I don't know what my cause was.

[tomtom]

Just to let you all know.. The engine has been removed and no bits of clutch fell onto the floor.. so we are no closer to finding the cause of the noise!

[David W.]

I found no internal signs. I concluded that it was the exhaust banging against the bulkhead about a foot downstream from the manifold.

[hanvyj]

I have these exact same symptoms and haven't found out what it is yet. Replaced the engine and it remains. Going to try replacing the universal joints.