Rr td6 2003 gear box issue

Rr l322 td6 2003 123k Lost drive of gear box drove home yesterday had trans fail safe on dash felt as if was slipping had burning smell like from A clutch stopped car and left on road
Went and got diagnostics snap on
Tranfer box no fault
Gear box x3
Actuator fault
Low battery batt new march 19
Gear 2 fault
I'm thinking possible torque converter blown put debris In to gear box filter starved tc of oil I having yet taken off sump cover to see if there's any debris as yet awaiting advice
Mate at garage has launch gear box flush machine that clean all oil out from gear box tc and oil cooler £300-£400 for double flush
Or is it £2.5k rebuild
Service history is unknown on gear box I have had rr for 2 years and not bothered expensive mistake land rover have never done it says sealed for life I left it alone until I found out otherwise was booked in at rr specialist to be done tomorrow
Just had mot done flew through that fun and games of rr l32w
Thanks for your time
If poss rebuild might not be worth doing due to age ?

The TQ This is the big one. The most common problem with the GM 5L40-E transm is torque converter failure. For a variety of reasons (torque converter solenoid, worn valves, worn converter) the converter fails and begins contaminating the oil with debris. The debris circulates throughout the transmission and, eventually, begins blocking the filter. Once the filter is clogged up, the clutch packs are starved of oil and begin to slip. The slipping clutches begin to burn up, further contaminating the oil with debris and, well, you get the idea..

Best get it rebuilt, a flush will do nothing, if anything might make it even worse..

Also prolly worth checking the battery, if it's showing low voltage that will cause more issues of it's own.

The td6 box is well know to be made of soft cheese and gives up the ghost, do not flush box it will loosen all the rubbish in he box that is sitting happily out of the way doing no harm, the boxes are known to throw a fit at mileage 80k and over the problem is the valve block and that needs to be rebuilt with a sonex kit, other on here will give you more info.

Thanks for info
Looks like rebuild lines I was thinking
Battery is ok 12.6 and 14v charging
1000 c amps