Torque converter taking a while to lock up properly

jamesmartin · May 5, 2011

you wont be fitting new valve block maybe second hand one ,easy enough to fit as long as you undo only the rigth screws

fishsponge · May 5, 2011

Thanks for the info Graham... mine's not a Disco II though... it's a Disco 1, but the web page you linked to does seem to suggest the gearbox is very similar.

However, it says "In New Discovery, gear selection, gear change speeds and torque converter lock up are now controlled electronically/hydraulically, rather than being controlled by mechanical/hydraulic means.".

So, in my vehicle it is mechanical/hydraulic rather than electronic/hydraulic, as I suspected.

Also, the Disco II gearbox seems to have a torque converter lock-up solenoid... I'm not sure if mine has such a thing. I suspect not, but i think it's irrelevant.

It also says "New Discovery will lock the torque converter in all gears.". My Disco 1 does not, and should not, do this.

Finally, it says "The torque converter will not be locked until the transmission has calculated that the oil temperature has reached a predetermined temperature. This is calculated from the engine coolant temperature via a software timer within the TCU, as the transmission itself has no temperature sensor.".

I'm 99% certain my 300Tdi does not do this as it doesn't have the same level of electronics as a Disco II.

Also, when mine tries to lockup, you can hear the revs change and see the rev counter drop, but it doesn't drop as much as it should and it still varies as you "pump" the accelerator, so it's obviously trying to lockup but failing, if you know what I mean......

jamesmartin · May 5, 2011

your control is all in box apart from kick down cable input

sandu · Mar 2, 2020

I have a question regarding an automatic gearbox on a Discovery 2.

recently, I received my rebuilt transferbox, which has different ratio from factory.
I opted for 1.41 transfer ratio for my big tires and usage.

I observed that the Torque Converter is not locking all the time now. It locks rarely and only when driving on flat road... is that somehow concerned to transferbox mod, what involves the rpm change?

jamesmartin · Mar 2, 2020

sandu said:
I have a question regarding an automatic gearbox on a Discovery 2.

recently, I received my rebuilt transferbox, which has different ratio from factory.
I opted for 1.41 transfer ratio for my big tires and usage.

I observed that the Torque Converter is not locking all the time now. It locks rarely and only when driving on flat road... is that somehow concerned to transferbox mod, what involves the rpm change?

drive shafts are going slower than your road speed as would be with standard tyres, it locks up about 50mph,as std

sandu · Mar 2, 2020

Tried to drive steadily with 50 mph, 55 mph, 60mph, 45 mph...
It locks only at 50, and not all the time, only when I drive easy and the pedal is depressed just a little

jamesmartin · Mar 2, 2020

are you actually doing 50

sandu · Mar 2, 2020

Yes, it is not concerned to tires, because I have these tires for last 2 years.
It locked all the time before this mod.

I observed this issue appeared after fitting the modified transferbox and changing fluid in transmission.

jamesmartin · Mar 2, 2020

sandu said:
Yes, it is not concerned to tires, because I have these tires for last 2 years.
It locked all the time before this mod.

I observed this issue appeared after fitting the modified transferbox and changing fluid in transmission.

ok, how did you checkbox fluid level

sandu · Mar 2, 2020

It doesn’t have a dipstick.

Filled the transmission sump, started the engine, filled again, started to move selector through gears and still filling until the oil was leaking.

shall I re-check the fluid level?

jamesmartin · Mar 2, 2020

sandu said:
It doesn’t have a dipstick.

Filled the transmission sump, started the engine, filled again, started to move selector through gears and still filling until the oil was leaking.

shall I re-check the fluid level?

sounds right,though you only have to move lever through gears once,what was old oil like

sandu · Mar 2, 2020

Old oil was not very old, because I did the last fluid change 6 months ago..
Now, because the transfer box was out, I decided I have to remove the gearbox too, removed the Torque Converter, replaced the flex plate and fitted everything back on.

also, changed filter and sump gasket

sandu · Mar 11, 2020

well, changed one more time the oil as scheduled.
lifted the front of vehicle with 10cm, so that I ensure I can fill a little more oil in the gearbox.

when driving, I observe that torque converter still doesn't lockup.

any advice?
did I affect it somehow by changing the transfer box ratio from 1.21 to 1.41?
or my solenoid failed?

sierrafery · Mar 11, 2020

sandu said:
did I affect it somehow by changing the transfer box ratio from 1.21 to 1.41?

Off course as you physically modified the torque request at a certain rpm while the fuel map is set for the original ratio, if the tyres you have are also as in your signature(275/70/18) which means more than 14% difference the whole management is mixed up, dont expect it to behave well unless it's remapped as to match the actual conditions with the altered VSS, you should find many posts of mine where these things are explained, automatic Eu3 D2 has a way more complicated management than a defender, modifying the VSS such way is not wise at all ... if you dont have EGT gauge better fit one ASAP .... read the whole thread https://www.landyzone.co.uk/land-rover/1-667-1-transfer-box-in-a-disco.356288/#post-4776737 concentrate on posts 17, 18

Torque converter taking a while to lock up properly

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