I installed a transmission mount on my 88 240 today. I went with the circle mount vs the more expensive square mount. It worked out nice, as the vibration was gone. I had to jack up the trans to take pressure off the mount. I used a 4x4 block of wood the length of the transmission pan. I was looking for anywhere else to jack up the trans, but did not see anywhere else. I looked in the Haynes manuel for instruction, but it was vague and did not mention a whole lot as it usually does. I was wondering if this practice was okay? The car shifts and drives fine, but I just am wondering if I caused any damage? I just felt funny about doing it this way.