On mine it was a list of things each removing a little vibration.
Listed from the top down what had the most effect on reducing vibratin on mine.
Rebuilt injectors
Updated Rack Damper Screw
Fix an air leak by changing fue inlet hoses
Replaced motor and transmission mounts (none were broken but some were soft due to oil saturation).
Replaced one Engine Shock/Damper (I ruined one getting it off)
Readjusted Rack Pin Damper.
In fact no one has mentioned replacing the Engine shock or the Engine Shock mounts if these are not OK they will not help reduce vibration. Also a goodTransmission Mount will help decrease vibration.
Idle speed set too low.
The Rack Damper Screw can be see protruding from the middle rear of the IP in this diagram where the pump is shown completely assembled; and is item 259 is the O-ring and item 257 is the Rack Damper Screw in the Exploded View.
http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=123132&M=617%2E912&GA=722%2E118405&GM=716%2E005++++++++++++++717%2E400&CT=M&cat=143&SID=07&SGR=045&SGN=01