knocking from drivetrain under hard acceleration

[djc]

Hi All,

I have a loud rapid knocking sound from the drivetrain (sounds like from the front) under full throttle from a standing start. its short - maybe 4 or 5 solid knocks as the car moves from a stationary position.

No noise at all during rolling acceleration.

This occurs with no steering lock on and there's no noises from any of the the CVs when turning - both fronts are refurb items and are in good condition.

My indie says he's never heard the sound before.

I have just had the following replaced: front caster bushes, diff bush, RHF control arm and had a wheel alignment done. Indie says the suspension is in good shape.

I have searched the site as well as I could, and the only things I could find was transfer case chain slipping or a drive shaft bearing failing.

Do either of these sound right in my case? has anyone had anything similar?

Car is a 2003 4.4i E53 X5 with 143000kms (approx 90,000 miles)

cheers

David