A Curly One D4 Major Gearbox Fault

[Fos90]

Over the last few years while driving on dirt roads or i guess rough roads our D4 shuts down with major gearbox fault. Ok stop turn the engine off restart then drive away like nothing happened. Its happened more often while we drive over cattle grids you know the vibration that rips through the car.Then the other day it happened on the M5 not fun when you loose all power and need to pull over ASAP.It always occurs during long trips never short city trips.
It also happened when i was parked at Perisher Valley for a few days in sub zero temperatures started the engine fault comes up switch off then start up again the fault gone.
I am thinking this is some sensor not a major gearbox fault because its been going on for years.All my mechanic suggested was battery voltage.
Any help would be appreciated
Thanks Mark

2.7 2010

[Graeme]

Start with having the engine and gearbox fault codes read. If the codes haven't been cleared for some time then possibly best to clear them then interrogate them after the next fault occurs.

[xoa]

Hi. How many kms and have you had auto serviced? Despite LR claims of sealed for life transmission they now suggest replacing fluid at 100,000 km or sooner if you tow or do lots of off road. I know from costly experience that it can lead to a rebuild if not serviced. Service casts about $900.
Xoa.

[101RRS]

Despite LR claims of sealed for life transmission they now suggest replacing fluid at 100,000 km or sooner if you tow or do lots of off road.
Xoa.

That claim is a furfy and LR does not claim it is sealed for life - the service requirements are listed in the service schedule and while it is extended it is not sealed for life.

But you are correct, the gearbox oil should be replaced at less than 100,000km intervals.

Garry

[DiscoJeffster]

That claim is a furfy and LR does not claim it is sealed for life - the service requirements are listed in the service schedule and while it is extended it is not sealed for life.

But you are correct, the gearbox oil should be replaced at less than 100,000km intervals.

Garry

I agree Garry however ZF themselves have conflicting information published. See the attached sheet from ZF which states "lifetime fill", whatever a lifetime is.....

[101RRS]

Certainly does not help.

[Allycat]

So if I mostly use my D4 to tow, and it's done 185,000 kms, you guys would recommend I get the transmission oil changed, even if there's no obvious sign of any issues?
I'm confused about this - my dealer told me don't bother, then a newer closer dealer told me I should do it (but they charge exorbitant amounts for labour, and told me it would be $1500 assuming they found no faults and changed the fluid).
I'm also reading that I should change my oil every 10,000 kms if I tow regularly?
I'm starting to think I've really let my poor car down.

[101RRS]

Yes defiinitely get the fluid changed - not sure of the 8 speed but if a 6 speed also get the plastic sump changed to the metal one and a new filter.

All up with a megaflush of LG6 oil should about $900 at a good transmission place.

If an 8 speed - not sure of the metal sump but get the fluid and filter changed.

Garry

[rocket rod]

Here is an extract from a service manual you might find interesting

The maintenance items listed, are those recommended for vehicles operating under normal driving,
road and climatic conditions. More frequent attention may be necessary if the vehicle is subject to
stop/start operation, extremes of temperature, dusty conditions, off road driving or frequent towing
of trailers.

I do a bit of off road driving and I still get it serviced every 10K and the transmission 80K

[Fos90]

Thanks everyone for your interest but i am more concerned that major gearbox fault light comes on with complete loss of power with absolutely no problem after the engine is restarted.
It to me appears to be some sort of sensor If anyone has any ideas please let me know.
Its no fun driving down the freeway at 110 then nothing its dangerous
Thanks Mark

[101RRS]

Have you done what Graeme suggested early in this thread - get the codes read - this is what you need to do first and then take it from there.

[Fos90]

Yes i did and there was nothing showing up that my mechanic could put his finger on apart from low battery voltage
its happens so randomly and has been going on for several years.
How could a major gearbox fault be rectified with a restart.

[DiscoJeffster]

Yes i did and there was nothing showing up that my mechanic could put his finger on apart from low battery voltage
its happens so randomly and has been going on for several years.
How could a major gearbox fault be rectified with a restart.

The fault is not rectified. The system has parameters it works within. If something such as a pressure goes outside specification it will flag an error. When you restart it clears the errors and until you next hit the low pressure, it won’t fault again. The physical fault is still there, but the outcome which is to shut itself down and protect itself will reset until next activated.

You’ll have to get a diagnostic tool onto it when it’s failed if it’s not storing the faults.

[Graeme]

Can the mechanic's diagnostic tool read gearbox DTCs or is it only retrieving PCM DTCs? A gearbox fault that triggers a message should always have also stored a DTC in the TCM.

[Rextheute]

Give A & B Trans in Dandenong a call - they are ZF experts - will be able to read the faults and change the oil / filter in trans .

Very user friendly .