I paid half upfront for an engine swap, after they took out the engine they are claiming transmission and catylic converter got damaged.

Is it even possible?

 

Exactly what kind of damage are they claiming, EXACT DAMAGE, not just "tranny got damaged".

Get pictures as well.

Physical damage on the catalytic converters is possible, the nuts/bolts that hold it to the headers usually have corrosion on most cars and they can snap off. Not a big deal, put new studs in. That's usually the only "damage" that happens to the cats, any reputable shop will easily fix this either by using new studs or getting a generic through-bolt kit.

Transmission however, the only way it got damaged is if they did something stupid like dropped the torque converter on the ground or other mistakes. Obviously their responsibility if that's what happened.

Again, EXACT DETAILS, and PICTURES.

 

Can you elaborate on how the engine was destroyed?

Is it a manual or automatic transmission?

A "blown engine" usually means a rod bearing failure. Could also mean a broken piston.

Neither of those are going to lead to either CAT damage or transmission damage, especially if its an automatic.

I have seen certain GM engines (3.8 litre series 2 v6) destroyed when their plastic intake manifolds crack and coolant enters into the intake stream and causes a hydro-lock when instead of an air fuel mixture filling the cylinder and then being compressed, coolant fills the cylinder and you can't compress it. The result is like the piston hitting concrete. Everything stops instantly and the pistons and rods are destroyed. Couple that to a manual transmission and yeah, up goes your transmission in shattered gears.

But an automatic transmission doesn't have a direct connection to the engine.

So I don't get it either.

You're talking serious dough for a new engine, transmission and 2 new cats.

 

My guess is they didn't correctly install the torque converter (didn't get it properly backset/clocked) and ended up damaging the transmission oil pump. And they probably broke all the bolts off on the catalytic converter and don't know how to "fix" it.

 

When the torque converter locks up it does...