Bad install on engine causing Tranny Leak?

I have a 98 Ford Taurus w/the V6, 3 liter engine. Back in March, I had a used engine installed because the head gasket went (there were other problems also). I found the transmission fluid to be leaking last week and when I took it to my mechanic he told me that it was most likely the front seal. The first question he asked me was if I had an engine put in recently. When I told him I had, he said he thought so. He didn’t elaborate. Could an incorrect engine install cause the front seal to fail ???

Yes, it can. Whenver an engine is changed out the proper, and recommended, thing to do is change the torque converter (front pump) seal. IMHO, this is a MUST.

The old seal has hardened with heat and time. With the engine out the torque converter has a tendency to sag a bit since it is not bolted to the engine flex plate.
This sagging, and movement of the converter when reinstalling the engine, can crack or break pieces out of the old seal.
It will then leak.

If the shop did not replace the seal, this is a mistake on their part IMHO. The seal is around 8 bucks or so and a reputable shop should really only charge for the price of the part with no labor involved.
The engine is out and it’s a 5 minutes or less deal to remove the converter, the old seal, and reinstall the new one.

Hope that explains it. You might check your copy of the bill and see if they charged out a seal; if not, they erred.
I would also always change the engine rear main seal before installation for the same reason. Why risk installing an engine and then having it develop an engine oil leak from a rear main the next week?

I know they did not pull out the torque converter and replace that seal. Unfortunately I’m not sure I have any recourse at this time. The tranny was down 5 quarts and I thought for sure that damage to it had occurred, but this mechanic said it was fine once he refilled it.