Oh Honey,
If your perky it would make me perky, and I admit I may be inclined to give you a perk in hopes there would be a bit of mutual percolation ....
.... if your rear looks to be leaking fluid the leak may not be that bad and your rear may still be sufficiently lubed.
Gear oil leaks tend to look worse that they actually are. I checked the level in the truck and damned if it didn't look like there was rear end lube running out of the bung for 6 months after. It's the nature of gear lube.
>>>>
So ...
You've had a trans go bad. Then another. You replaced the trans with a factory unit and a new shaft but it's jumpuing out of gear. Or it was.
Now the backsides leaking liquid.
You wouldn't by chance be leaking out of the pinion seal.?
I think if whats happening is what I think is happening you need your car checked by someone who can be critical of not only others work but of their own as well, and this person needs to know what their looking at and for.
Mainly alignments.
If you brought the car to me I would level it, break out the precision tool(s)(ing) and hang plumb bobs. Before I started anything you would know where everything is.
>>
I would have hte driveline looked into, these sudden changes really arent normal.