I went out and had a quick measure up of the wishbone this morning; the distance between the sub-frame ball-joint and the hub ball-joint is about 14" (350mm). If the fulcrum is placed around 2" (50mm) from the sub-frame ball-joint it will give a mechanical advantage of 7:1. I don't know how much force is required to compress the coil spring, but I guess it must be several hundred pounds, multiply this by seven and the pulling force exerted by the spring must be considerable! The larger the diameter of the fulcrum between the sub-frame and the wishbone the more the spring has to be compressed and the greater the resultant force. My first thought was to use a large socket as a fulcrum, but there were some slightly ominous cracking noises as I lowered the jack under the hub ball-joint and I was concerned that the thinner part of the socket might be crushed, so I substituted the hammer head.
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