1992 Ford Ranger Transmission

I am the original owner of a 1992 Ford Ranger Supercab XLT, 4X4, 6 cyl 4.0 liter, C3 automatic transmission with 150K miles now. First 15 yrs it was garaged, last 3 in driveway parked on an incline. Few mths ago it started slipping out of Drive or not wanting to go into drive, meaning it would not engage, like being in neutral. My mechanic (who owns same yr model truck as I do) said it was the stearing column connector ring that was leaking fluid while I was driving and it was down two quarts of fluid. He said the ring should be round but mine was elongated- like oval shape so he replaced it. He adv me it was ok to continue driving but watch the fluid & add if necessary but also adv he thought the trans fluid pump may be damaged. I did continue driving and over a course of one month the leakage slowly continued- meaning at the end of 1 month I put in one quart… Until the last time I drove it I went out approx 40 miles from home, checked the level, it was fine, and nothing on ground, however on the way back approx 10 miles out, I noticed a fine faint white smoke trailing me, I pulled over and looked underneath the vehicle only to see what appeared to be the pump pulsating the transmission fluid out onto the ground near the oil pan (driver side of pan-- I change my own oil so I know where the pan is) Needless to say I dumped approx 7 quarts as it continued to leak just to get me home, it has been in my driveway since. Is it possible to change the pump without pulling down the transmission or could it be something else?

It could be a transmission cooling line has come loose or is cracked and leaking. These line come off the internal pump, and send the trans fluid to the cooler and back. If it is a pump seal, the pump is located on the input shaft of the transmission, and the trans must come out to get to it.

Well considering that the fluid pumps out on the ground when engine is running I will most likely have to have the vehicle towed to a transmission shop, although there is a transmission shop less than a mile from me do you think I could dump more fluid in it and drive it myself? Before I do that, where/what does the transmission cooling line look like? Is that something that can be easily replaced and less cost? Is that something I would be able to see externally? From your reply I gathered the internal pump is not the same as the sealed pump? Or is it the same part just depends on my type of transmission? I know very little about the mechanical function of transmissions. I have not crawled under the vehicle since that time to see exactly what it looks like under there, as in where this leak is, but my mechanic indicated the last time that a transmission overhaul would be next if it was the pump, so I am assuming it must be a sealed pump, I am beginning to question further using my garage mechanic as recent events concerning this vehicle makes me question that he is the reason I am now in this position- therefore, would only a transmission shop be the wise choice to take it to? If I am looking at an overhaul, this will be something that will be way down the road (like next year) as I am currently unemployed and have been told this is approx a $1600 job, what can I do to take care of my vehicle in the meantime while it sits in my driveway? Its not driveable at the present, and I have heard letting an engine just idle is bad.