The current thread concerning the replacement of motor mounts has prompted me to describe the way it can be done safely. I have done this numerous times with no problems whatsoever. This method is used when an engine lift or support beam is not available. The first step is to place the infamous block of wood on a floor jack lift pad. The block must be wider than the oil pan in order to distribute the load over the largest possible area. The block/jack should be positioned so that the flat area of the pan towards the bellhousing is the area that will carry the load. The intent is to have the block contact the pan past the edge of the pan on both sides of the pan and at the rear of the pan. This is where the moment of inertia of the pan is highest, thus, the strongest area of the pan. Under no circumstances should the block of wood be positioned where it will exert any lifting force on the oil plug region of the pan.
The next step is to apply just enough lift to remove the pressure on the motor mounts. Place a block of wood between the steering rack and the oil pan. This is to prevent the engine from being able to move should anything happen with the jack causing it to release. I must stress that I replace the mounts one at a time in order to keep the engine constrained from movement. If uppon lifting the engine you notice that either mount is broken/seperated, start with replacing that mount. This way, you have the opposing mount keeping the engine in place. Once you decide which mount you will replace first, remove the 3 nuts holding the lower mount bracket to the crossmember. Next, put enough pressure/lift to the jack to the point you can wiggle the lower bracket freely i.e. no pressure/weight being carried by the mount. Now, remove the 3 bolts holding the upper bracket to the block and lift the mount and brackets out of the engine bay. Now, remove the mount from the brackets and replace it with your new mount. Reverse the above proceedure and you have one of the mounts replaced. Do the exact same thing for the opposite mount if necessary. It usually is necessary since the mounts tend to fatigue at approximately the same rate. Be sure to remember to remove the block between the pan and the steering rack before lowering the jack. At no time during this proceedure should you reach between the engine and the crossmember. As far as any risk of getting killed during this proceedure is concerned, that is an incredible exageration. The engine can only drop the distance of 1 inch before the pan is sitting on the steering rack. It cannot fall on you. The car itself can. Be sure to support the car itself properly if you raise it in order to get more working clearance. This proceedure requires the same amount common sense as the one used by Volvo and if performed correctly, will net the same results. And yes, if you have the support beam or an engine hoist at your disposal, use them instead. Just remember, even with the so called, "proper equipment", you still run the risk of the engine dropping, so, a safety block between the pan and the steering rack is a good safety margin. Remember, safety first. A visit to your local mechanic is usually cheaper than a trip to the emergency room of your local hospital.