Replacement transaxle bad?!

Replacement transaxle bad?! So the 2007 Prius transaxle went out at 160k. I had my mechanic replace it and now another weird issue. I haven't seen this anywhere on the forums or net.

So the question is - did I get a bad transaxle and need to replace again?

Here's the history :
Flooring up hill on highway lights came on. After pulling over the "trans" made bearing buzzing noise when driving and only gas engine on. Drained and metal shavings. Replaced trans with 80k junk yard trans 3 days ago. Drove fine but accelerating hard from dead stop a shaking developed. For testing to replicate problem car would shake/shudder violently from stop with 3/4 throttle accelerating. Shakes the whole dash like clutch chatter or driving over washboards in first road. Light throttle would be fine and car drove perfectly moving. I initially thought the fixed clutch was bad because it felt and shaked like clutch chatter but now it's shaking with just letting off gas and electric only from stop. It didn't start out doing this right away after transaxle replacement and developed in 2 days. So when you are stopped in drive with gas engine off you let off gas and feel shaking/chatter and see the engine shake back and forth. With hood open standing next to car while having someone else drive it you the engine shakes back and forth. Had my mechanic check for lose mounts and bolts but seems fine. Problem is my mechanic isn't familiar with Prius but a great mechanic. There are no lights currently. Coasting at 50 mph feels like the engine is labored and need more throttle than normal.

Anyone ever have these symptoms? Was I unlucky to gets bad transaxle even though it only had 80k? Or is this something else besides transaxle?

 

I bought car a year ago at 130k miles and refreshed transaxle fluid then. When I had failure at -160k and drained by the Prius electrical/ battery guy he said it was 3 quarts instead of 3.8 quarts. So perhaps my mechanic didn't put enough in or it leaked out? I was there when he refreshed and saw the fill hole full. The replacement transaxle was drained, filled , drove five miles, and drained and filled again. He said it was initially dirty. The transaxle was cheap $150 - but they had it uncovered outside so who knows... i supposed I could try another drain and fill but don't know if that is a waste of time or worth a shot. Ill see what Steve says