If you will already incur the cost of removing and installing the AT, why not fix the one you have?

The issues with the 5hp24 that I have seen sofar on this board, including my own, are broken O-rings and worn radial bearings. These problems generally seem to come to the fore when the torq converter fails and spits a load of metal shavings into the AT exacerbating any minor pre-existing problems. Most of the guys who have done their own overhaul report the clutch friction disks to be in good shape but worth replacing them once you have it apart. I replaced my output bearing and to that I attibute the yet more quiet running of my 4.4.

Last weekend I ran it for 300 mile roundtrip including a nice stretch of I-81 where things were moving along briskly despite occasional downpours fro Irene and it was a joy to drive.

I would always rather fix and re-install the item that came with the vehicle than swapping in something I know much less about and may have a lot more miles on it.

The parts are about 700-1000 retail and the labor should not be that much. Good luck with the fix!

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2003 4.4i black ext./black int./black headliner (kid's runabout)
2014 535d X-drive, M package, silver/black interior

Sold but not forgotten:
2009 E70 35d, black ext./black int./black headliner (sold 2021)
2006 4.8iS Le Mans blue/cream int./black headliner, SOLD in 2012 sadly...

Other hardware:
2015 Cayenne S (wife's new DD and definitely wroooommmmm)
2016 Tundra 1794 edition crew cab, luxo hauler
2005 Tundra crew cab, weekend hauler. Sold after 150k very happy miles.