Loss of power after trans seal replacement
 

2009 Hyundai Accent SE automatic

I just changed the transmission seal that's behind the torque converter because it was leaking like a faucet. Got everything back together and the leak is fixed. GREAT!
Start the car up and put in reverse. It shifts into gear fairly harsh. Put it into drive and the same thing happens. Took it out for a drive and it barely has any power. I floor it and it feels like its in a bind. Has a hard time getting up to speed. I'm thinking the transmission is shot. A few are available used. Anybody have any ideas on what direction I should go in? Thanks

The torque converter has two drive tabs that must index with the pump gear inside the trans, are you sure you had the converter hub indexed properly with the slots in the gear?

I put the converter on the shaft and it went down some and stopped. I then began to turn the converter little by little while pushing inward to find the second drop. I assume this is the spot that is dropping over the drive tabs. Everything seemed to seat ok. Is there another drop that should occur? I had about 5/8" from the front of the converter to the front of the bell housing. It does make sense that the converter is not engaged and not providing transmission pressure. I'm going to have to drop the transmission again to either swap it out for another or salvage the one I have and make sure the pump is working and the converter is engaged. You have an idea how to check the converter is engaging the pump?

If it was indexed improperly ,there is the possibility of damage to the pump drive gear. I don't believe you can confirm this without removing the pump front cover assy of the trans.