This does not IMO appear to be a vcu related 'noise' issue . - most likely CV but also consider IRD issues,
Check - as a matter of urgency, the rh inner cv joint - and of course the outers. It is strange that you say are getting noise only when turning right - so it appears
Your problem could well be the IRD - not simply the VCU. - of course, it could also be something much less serious like a CV joint.
Can you feel anything through the steering when it 'knocks' ?
Drive the car in reverse on full lock in both directions - slowly, also forwards on full lock and see if you get any unusual noises or knocking or feeling as if the brakes are being slightly applied at full lock. The OWUT is also viable however you need to identify where the noise is coming from immediately , if it IS the ird the damage is done.
What makes you say it is 'coming from the VCU' ?
'clonking' as you put it, especially on lock, in a 'normal' fwd vehicle is indicative of cv joint issues. On a freelander, it is also thus, BUT, also potentially indicative of IRD failure. There should be no play at all in the cv joints. The rh inner - where it enters the IRD can cause catastrophic failure of the IRD if there is excessive movement in the CV.
IF it is the IRD, (and let us hope it is something else and much simpler and cheaper - like a cv joint ) - then as said the damage is done.
If you think the noise is coming from the middle of the car underneath when on full lock then it is probably coming from the IRD input pinion to crownwheel (another type of ird failure - if ird it is usually the input pinion to crown wheel teeth - or, the rh inner cv area where the main concentric shaft / diff unit pass drive to the output shaft in the ird), unlikely to be the VCU at all (making the noise) - the VCU may well be captain cooked though.
Can you feel anything through the steering when it 'knocks' ?
Just to add, if you have pumped up the tyres and the sound is less then it is unlikely to be either a CV or the VCU.................