2000 V70 trans problem need info

[oldtimertoo]

Hi there. My problem started with the lower gear arrow lit up while the trans was funtioning fine, then it started flashing but still working ok. Read the codes and got a p0740- torque converter clutch. Then it started jumping out of the gears - as you would accelerate it would jump out of first, let off the gas and it would go into second and then pop out. And the arrow went out and hasn't come back. Then it started hunting and wouldn't stay in any gear. Still no trans code. I did get a TCU code (and it seemed it was acting like it didn't know what it wanted to do) so I put in a different (used) TCU and it ran ok for a few miles and started the same stuff all over again. Still no trans codes. Now it will hardly run and is showing code P0734- gear 4 incorrect ratio. Is the trans totally shot? Solinoids? Electrionics? Any one have any ideas? Anyone know how to test this thing? Do you have to pull the trans to fix the torque converter clutch solinoid or the other solinoids? BTW- the oil looks and smells ok. Any knowledge would be much appreciated. Thanks