I have had the dreaded clunk when switching off my car and told I need a new RH engine mounting. I have been putting it off because of cost and the actual work..
Last week I bought a new mounting and started the job. When loosening the top nut of the engine mounting, I found that it was already loose and that the mounting was actually fine. I suspect that the turbo hose leaks some vaporised oil from the air circulation system which lubricates the nut and eases it loose.
I loosened the nut, sprayed the top with carb cleaner, put a drop of locktite on the bolt and tightened the nut. For peace of mind, I put another nut on top to act as a lock nut.
I suspect that this is a general problem as it seems that everyone is replacing the RH mounting. I suggest that a little afternoon work will save some people a LOT of money. It is very easy to do and only requires a 10mm socket and a 14mm socket and some time. Most mechanics seem to replace the mounting when they diagnose the dreaded clunk.
My Pajero has less vibration and the gear changes are noticeably smoother.