gearbox rattle

hi my 1999 discovery auto has a rattle coming from the gear or transfer box area, this only happens at 2300 to2500rpm, if you accellerate hard it dosen,t do it, there's no problem with gear change and there dosen't appear to be anything lose underneath,
anyone got any idea's
thanks
david

David,

I know the place, been there for months... doesn't it sound like a stone in a tin can?

Replaced:
- engine mounts
- transmission mounts
- down pipe (de-cat'd)
- mid silencer
- exhaust system rubber supports

Whilst all of the above improved the vehicles drive (it actually eradicated a much annoying cabin rattle at idle) the dreaded rattle did not go away.

Overhauled transfer box (had minor leak from input shaft seal) & while doing so scoped all areas surrounding gearbox for loose parts, to no avail.

Have lately concluded it is the torque converter's plate being cracked. This appears to be relatively common in Td5 Autos... I have read at least a dozen posts where similar symptoms are described. Even Ashcroft makes mention of it.

There is small plate (~2" diam, 'D' shaped I believe) screwed at the bottom of the TC housing, it looks as if one could remove it and run in with some sort of inspection device... currently planning on buying an endoscope type USB camera to try confirming the problem before I shed £1200 in a new TC.

Rgds

Matt