What are the symptoms?

[HeyAndy]

My car has developed a sort of clunking sound which seems to be coming from the transmission tunnel as though something has worked loose. When I brake you can feel it moving under the braking forces.

I bounced the car up and down on the O/S and heard a similar sound. I'm now thinking that it could be a couple of bushes but not sure what the symptoms are.

Anyone have any similar experiences or possibly could shed some light on this strange occurance?

[kevinday]

Could be a variety of things, you need to get under the car to see. UJs, propshaft, diff, brake discs/calipers, drive shaft, gearbox/engine/diff mountings etc. I believe drive shafts are slightly more prone thna some of the others.

[wedg1e]

If you want a good look at the goings-on under there, park the car on a clear stretch of road with 2 wheels on the pavement. Lie underneath and have somebody bounce the clutch around its biting point (with the engine running, obviously). This loads up the drivetrain and is the quickest way to spot all manner of nasties from clonking UJs to worn bushes.
Did this with my mate's Lotus Elite and found the diff was only hanging on to the chassis by the will of Allah...

Ian

[streaky]

wedg1e said:

If you want a good look at the goings-on under there, park the car on a clear stretch of road with 2 wheels on the pavement. Lie underneath and have somebody bounce the clutch around its biting point (with the engine running, obviously). ...

But not in gear! I presume

>> Edited by streaky on Monday 15th September 15:34

[Nacnud]

Mine has a clunk under engine braking on rough roads which I belive is the exhaust touching the chassis. It's really tight under there!

[HeyAndy]

I had a look underneath and discovered there's a fluid leak directly on top of the silencer from the driveshaft end.

The car pulls away cleanly so it not driveshaft related as there is no clonking from the rear though I'm not sure where the fluid is coming from. The sound is more as if something is moving about, as if the gearbox seems to be moving hence the feeling through the transmission tunnel.

Am baffled I must say!

[wedg1e]

streaky said:

wedg1e said: If you want a good look at the goings-on under there, park the car on a clear stretch of road with 2 wheels on the pavement. Lie underneath and have somebody bounce the clutch around its biting point (with the engine running, obviously). ... But not in gear! I presume >> Edited by streaky on Monday 15th September 15:34

Eh? Ah yes.... you need to be in gear... :doh:


>> Edited by wedg1e on Monday 15th September 20:01

[TaSmania]

My old 400 and the SEAC both have clunking under braking which is as per Nacnud the exhaust downpipe touching the chassis. If it's the gearbox feeling loose with noises it could be one of the rear mounting bobbins has gone. Get underneath with the car non-running and the brakes on and try moving the gearbox around. It won't go far but if the bobbins sheared through then it'll be obvious. These are about £30 the pair.
Have you eliminated UJ's as trans noise can be transmitted through the full drivetrain!
GB