Discovery 2A TD5 transmission lockup issues

[Jogormo]

Hi all my first post so sorry if wrong. But I need help my 2004 Discovery 2A transmission jumps out of lockup on the highway it goes from about 2200 rpm at 100km and as soon as you touch accelerator or come across a rise it will swing up to about 3000 rpm. It has 345000km and unknown history (yeah I know) It runs fine around town. But it is only locking up when I drop the accelerator such that rpm drops from 3000 rpm to around 2000rpm. And then accelerate again with an egg shell under the boot(very softly) and any rise in road will drop out.
I have bought a Foxwell nt510 and there are no transmission fault codes, I have done filter, and 3 X fluid changes in 7000 to get it right and 2 tubes of Dr tranny's. It has improved things but hasn't changed this fault. I have reset adaptive valves but this issue remains. Monitoring solenoid valve 3 on foxwell goes from open to opening but never closed will check on mates disco 2 if same as mine over weekend as this might be chinglish issue.
When it drops of of lockup it is still showing on the computer as being in 4th gear is there someway the valve isnt engaging fully causing it to not lockup properly.
How do I tell or am I looking at a dying torque converter?
Has anyone else had this same issue help please!
🤔

[Pedro_The_Swift]

Welcome to AULRO.com[smilebigeye]

At those kays and with an unknown service history I wouldnt be at all surprised if it gave up all together,,
LOTS of posts on symptoms like yours,
Some good posts on exactly how the TD5 should change gears too,,
I see LOTS of research/reading (in this very Forum) in your immediate future,, [thumbsupbig]

[PhilipA]

The drop out of lockup should not happen unless you floor the accelerator .
In cruise control it will happen more often as cruise will flatten the accelerator when losing the slightest speed.So if you are using moderate accelerator and keeping at 100 and letting speed decay a bit then it should stay locked down to 70kmh.
how is it in third? It should lock with blight. To moderate acceleration at 70kmh and stay locked down to 50.
regards Philip A

[Lemo]

Watching with interest, my auto displays similar characteristics.
I've done filter and 6 litres of AFT, plus another oil change due to breaking the flange off when changing the Transfer case!!!
Was better after the oil change but I think my D2 had a hard life towing!! So will be looking at a recon on the auto and maybe uprated torque converter?

What was the result after changing the adaptive values?? As I've not done this and maybe worth giving a try?

[lyonsy]

make sure the car is up to temp if its not the lock up can do strange things,

if it takes ages to lock up or is like someone slipping a clutch on car taking off id suggest the converter is starting to wear out,
or you possibly could have a valve body that is worn not applying full pressure to the clutch in the converter and allowing it to slip or fall out of lock up.
i am also pretty sure you can make the converter lock up with a switch so you could also test that way

I dont know if the 2nd thing happens for sure but it is what kills the 5 speed auto in the L322 range rovers that is serverly over stressed with the torque requirements being about a 100nm over what its designed to handle