Using a Floor Jack as a Transmission Jack?

My el cheapo transmission jack for use under my hoist jammed when i tried to lower it. It suddenly dropped and kicked out, leaving me holding up a caravan overdrive transmsmission half wedged in the engine bay. Got my shoulder under it so i had a free hand to reset the jack.
The next day i replaced the lower square tube with a 5,000 lb trailer tongue jack. So now i use a crank to get it near the working height, and use the hydraulic in the lower range of motion. It is no longer able to kill me. Added bonus, i get more height out of it.