I believe I have a failed motor mount(s), but have a couple of questions regarding the different mounts. I understand there are 3 located on the bottom side of the engine (excluding the top stabilizer mount which I have already replaced). The 2 larger 'ballast' type w/ cable strap and the smaller one on the passenger side near the oil filter. I am aware of the issues regarding the failure of the last mentioned and planned to change if collasped. However, I'm wondering about the other 2. I have read on the board that failure is less frequent on these. Are these the ones filled w/ hydraulic fluid? How often do these fail? How can you check for failure (i.e. engine lift w/pry-bar or visual)? I have the 'clunk' symptom in the steering column on initial acceleration and was wondering which mount would be the culprit. I have not thoroughly inspected the smaller mount on the passenger side, just looked at it when rotating tires to see if it appeared totally collapsed. I plan on checking it closely this weekend. As far as the other 2 I have looked at them occasionaly when under the car changing the oil but really didn't know what to look for. The rubber ballast looks great and barely has any signs of deterioration. I found a link to a really neat publication from a 'Brit' Volvo Owners site w/ an overall description of the 850 design/sytems and 3rd to last page describes the engine mounting. It sounds like the 2 larger mounts allow for the fore/aft movement of the motor which seems to be more indictative of this symptom than the other mount which appears to simply support that side of the engine
http://www.volvoclub.org.uk/tech/850GLT-EngineTechInfo.pdf