'86 Transaxle noise

I'm posting this to determine if its time for this car to go to the big parking lot in the sky.

Its a '86 Nova... a Chevy-badged Corolla. A few months ago, it started making a noise in the drivetrain, just a regular hmm-hmm-hmm that was speed related. I figured it was a bad CV joint. The boots are in nice shape, so I doubt it was that. I jacked it up, removed the front tires and ran it in drive. I was able to stop each wheel with my foot, and I hoped that would tell me which CV or bearing might be bad.

It didn't. The noise continued, I suppose from inside the transaxle.
I told her to just drive it, as I doubted a tranny replacement is feasible for this car, moneywise. She was mostly concerned about it as a safety issue, and I assured her no wheels were going to fall off.

They drove it quite a bit, and recently, it started making a _big_ noise.

But now, its not while moving.

The engine is relatively quiet at idle in Park, and revving it just gets the typical valve clatter and worn engine sounds.

But put the thing in Drive or Reverse, and the engine starts to strain (or stall) and it sounds a bit like putting silverware in the garbage disposal. However, it moves. I wasn't going to take it on the highway, but it puttered back and forth pretty well in the driveway, though it was noisy.

I'm thinking the transaxle is gone... and unless someone says otherwise, I can't imagine replacing the transaxle is going to be easy.

I'm usually stick to v8, RWD GM cars, preferrably 20+ years old... is there anything I'm overlooking here, or anything servicable on this transaxle?

Thanx.