Busted torque converter or trans?? Need help
#21
04-11-2014, 03:04 PM
Baja
ZF 4HP24 transmission - Wikipedia, the free encyclopedia
This from the Rave:
The automatic gearbox is a four speed unit with electronic control of gear selection, shift quality and torque converter
lock-up. Selections on the selector lever assembly are transmitted to the gearbox by a selector cable. A gear position
switch on the gearbox transmits the gear selection to an Electronic Automatic Transmission (EAT) ECU, which
outputs the appropriate control signals to an electro-hydraulic valve block in the gearbox. A mode switch enables the
driver to change the control mode of the EAT ECU. The EAT ECU operates warning lamps in the instrument pack to
indicate the control mode and system status.
The gearbox features a pressure lubrication system and is cooled by pumping the lubricant through an oil cooler.
On NAS market vehicles from 03 model year, the ZF 4HP24 transmission unit is introduced for use with the 4.6 litre
V8 engine. This transmission is required to accomodate the increased power output of the larger engine. The ZF
4HP22 transmission remains in use on vehicles with Td5 and 4.0 litre V8 engines.
Both transmission units are of similar construction, with the ZF 4HP24 unit being 15 mm longer than the 4HP22 unit
to accomodate a larger fluid pump. The operation of both transmission units is the same.
This from the Rave:
The automatic gearbox is a four speed unit with electronic control of gear selection, shift quality and torque converter
lock-up. Selections on the selector lever assembly are transmitted to the gearbox by a selector cable. A gear position
switch on the gearbox transmits the gear selection to an Electronic Automatic Transmission (EAT) ECU, which
outputs the appropriate control signals to an electro-hydraulic valve block in the gearbox. A mode switch enables the
driver to change the control mode of the EAT ECU. The EAT ECU operates warning lamps in the instrument pack to
indicate the control mode and system status.
The gearbox features a pressure lubrication system and is cooled by pumping the lubricant through an oil cooler.
On NAS market vehicles from 03 model year, the ZF 4HP24 transmission unit is introduced for use with the 4.6 litre
V8 engine. This transmission is required to accomodate the increased power output of the larger engine. The ZF
4HP22 transmission remains in use on vehicles with Td5 and 4.0 litre V8 engines.
Both transmission units are of similar construction, with the ZF 4HP24 unit being 15 mm longer than the 4HP22 unit
to accomodate a larger fluid pump. The operation of both transmission units is the same.
Just to add fuel to the confusion
, I have a 2003 TD5 (left hand drive) export model bought new in the UK (originally destined for Patagonia, Argentina) and that has a ZF_4HP24 autobox but I cannot say for sure whether it's just this model, or just some of the later models or was generally fitted latterly to TD5's. Who knows, after all it's LR. 
#22
04-11-2014, 03:28 PM
Baja
so there is no direct comparison. You may even find yours is a V8 to TD5 conversion. Be careful of believing you can shop in any BMW or Audi scrap yard as the box may or may not look or be the same but the greater likelihood is the bellhousing and TQ will probably be different depending on many factors unique to LR's.Whilst you've got the box out it may be very well worth while doing some other small jobs like checking out the internals of the xyz rotary switch (I can see it in your photos - you will need to drill out the rivets and then use M5x12mm nyloc nuts and bolts to reassemble it but use stainless steel instead to avoid corrosion) they have a nasty habit of throwing wobblies after a few years. Also check the A/C drains to ensure they are both clear and extend the drivers side drain tube downwards by 6 inches as it drains directly onto the xyz switch at present and can cause electrical problems and throw up M&S lights which switches on the 'limp home mode'. There is a thread somewhere on here that covers all those good things, just search for "xyz switch". Also check the autobox wiring for any chafing as it can be an issue. It's worth putting a strong woven nylon sheath around it to avert possible problems later. Good luck.
#23
04-12-2014, 06:57 PM
Baja
Some food for thought on this forum. It might help a bit.
Disco Td5 autobox: replacing torque converter
Disco Td5 autobox: replacing torque converter
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