Thumping Sound In Reverse

[abdallian]

Hi All

Is anybody able to give me any ideas what this sound may be.

I have a 1998 MKIV LS400.

Last few weeks when I put the car in reverse and roll out of the driveway I get a wierd thumping sound from the rear of the car. The only way I can describe it is as if there is a large half full bottle of water in the boot and the sound is as if the water is moving back and forth in the bottle with the sound amplified. The thing is it seems to be getting louder.

I only get this in reverse.

Any ideas as to what this maybe

Cheers

[ROYT]

Could be anything, jack up the rear and rotate all driveshafts,check bearings, prop. shaft couplings etc.

[abdallian]

Could be anything, jack up the rear and rotate all driveshafts,check bearings, prop. shaft couplings etc.

Thanks

Hope to get it up on a ramp next weekend.

Only happens when car is cold. Was worried it was a problem with the transmission.

Any thoughts