You can take a floor jack and screw a piece or two of plywood about 12" x 18" to the swivel plate on top. It works just fine and then you have wheels to roll it around on. This is what I have used for years, its cheap and it works just fine. There are specific transmission jacks out there but good ones are very expensive and many dont drop down very low so it makes it difficult to roll out from under a car unless it is up pretty high.