The oil used was Liqui Moly TopTec 1800, which complies with Land Rover 500050 specs, at least according to Liqui Moly.
Arto
 
@Bemble, can the solenoid resistance be checked to rule out heat issues on the relevant solenoid?
Could debris in the solenoid cause the issues and when the solenoid is used in conjunction with other solenoids to create a other gears could this hidden? :)
 
The oil used was Liqui Moly TopTec 1800, which complies with Land Rover 500050 specs, at least according to Liqui Moly.
Arto
But does it comply with the ZF specifications that seem to specify only one type of ATF to be used?
 
I don't know what oil was in the box before I let it be changed, because the previous owner changed the oil when the car had driven 137,000 km according to the service book, without any notes on the quality of the oil. I've been looking for compatibility of TopTec 1800 on the pages of BMW and Jaguar users who use the same ZF 6HP26 gearbox, and the comments are generally positive, saying that shifting happens more smoothly with this oil. In general, many websites say that other oils are used for the gearbox, e.g. BMW's service men recommend Mercon SP oil, which is Ford's oil, which has also used the gearbox between 2006-2008, e.g. in the Lincoln Navigator. Shell makes the ZF Lifeguard Fluid 6 oil to ZF and they make own exactly same oli in name Shell Spirax S4 ATF MSP and I think Ford's Mercon is also made by Shell. Despite everything, ZF has not accepted any other than its own ZF Lifeguard Fluid 6 oil for the box, which is difficult to find and expensive in Finland.
 
I came across a message like this on the Finnish Jaguar users' page 04.02.2019:
At least Land Rover has had a software update for that problem.
I remember the British called it the California stop problem. That
is, when you come to a stop sign, you brake and almost stop.
But if you press the gas, the transmission clonks. They have
been fixed with software updates.
Does anyone know what kind of software update is this about?
Arto
 
The very first problem which came to light with the 6HP26, following its launch in 2001, was a thump during the 2-1 downshift as the vehicle came to rest. This was a very well-known issue with Jaguar and BMW owners, particularly in the USA (where they dubbed it the ‘tranny slam’ – which could mean something completely different in the UK) and they actually created a website specifically to air their grievances with ZF over this issue. It was ultimately resolved by firmware updates to the controller software. It would appear that the way ZF had expected the solenoid adaptions to adjust over time had been a bad guess on their part and they subsequently tweaked the software to correct this.

Phil
 
@Bemble, can the solenoid resistance be checked to rule out heat issues on the relevant solenoid?
Although solenoid resistance is an easy thing to measure, it unfortunately only tells you the condition of the solenoid windings. The issues with the 6HP26 solenoids generally relate to mechanical wear rather than to an electrical problem:



The complete solenoid therefore needs to be tested, at different fluid temperatures, to establish its current vs pressure characteristics. A typical solenoid test is shown at 3:30-4:30 minutes in this video:



I get mine tested at Valve Bodies UK at Wallasey

Could debris in the solenoid cause the issues and when the solenoid is used in conjunction with other solenoids to create a other gears could this hidden? :)
As I've never come across this issue before, I certainly wouldn't rule anything out

Phil
 
Although solenoid resistance is an easy thing to measure, it unfortunately only tells you the condition of the solenoid windings. The issues with the 6HP26 solenoids generally relate to mechanical wear rather than to an electrical problem:



The complete solenoid therefore needs to be tested, at different fluid temperatures, to establish its current vs pressure characteristics. A typical solenoid test is shown at 3:30-4:30 minutes in this video:



I get mine tested at Valve Bodies UK at Wallasey


As I've never come across this issue before, I certainly wouldn't rule anything out

Phil

Jeez, so the simple solenoid has now become a more complicated unit that requires more time to verify its effectiveness on both the electronic and mechanical aspects!! I'll stick to my 38' and it's zf22 box:eek:.
Great info @Bemble ;)
 
Well, now the gearbox broke almost completely when I tried to pull my friend's car out of the snow onto the road.The box started slipping and after turning off the engine, it refused to start until it cooled down enough. When the car started, reverse worked ok, but forwards only gear 4 was in use. Luckily, the service repair shop I use was only a few kilometers away, so I was able to drive the car there.When the car cooled down for a quarter of an hour, the gears started working again.
I decided how to handle the matter relatively quickly and contacted a repair shop specializing in gearboxes. From them I got information about possible faults and repair taboos with price effects. On their recommendation, I ended up ordering a used gearbox. They promised to take care of the delivery directly to the repair shop I use and to instruct them in the exchange. The used transmission comes from the Netherlands and is from a 2009 Range Rover with 148,000 mileage, the delivery time is about 10 days. The total cost, including work, is estimated at €2,500.
And the story continues... I hope.
 
Well, now the gearbox broke almost completely when I tried to pull my friend's car out of the snow onto the road.The box started slipping and after turning off the engine, it refused to start until it cooled down enough. When the car started, reverse worked ok, but forwards only gear 4 was in use. Luckily, the service repair shop I use was only a few kilometers away, so I was able to drive the car there.When the car cooled down for a quarter of an hour, the gears started working again.
I decided how to handle the matter relatively quickly and contacted a repair shop specializing in gearboxes. From them I got information about possible faults and repair taboos with price effects. On their recommendation, I ended up ordering a used gearbox. They promised to take care of the delivery directly to the repair shop I use and to instruct them in the exchange. The used transmission comes from the Netherlands and is from a 2009 Range Rover with 148,000 mileage, the delivery time is about 10 days. The total cost, including work, is estimated at €2,500.
And the story continues... I hope.
148000 miles:eek: Make sure the cooler and pipes are either replaced or flushed.
 
And the story continues:
The following works have been agreed with the repair shop and they will start today
- Removing and installing the exhaust system
- Removing and installing the auxiliary frame
- Removing and installing the front cardan shaft
- Removing the gearbox and torque converter
- Transfer of the old gearbox control device to the gearbox arrived from Holland
- Installation of a new gearbox and torque converter
- Connecting the transfer gearbox to the new gearbox
- Replacement of the transmission oil filter and oil pan with one made of sheet metal
- Replacement of the transmission oil cooler with a new one
- Flushing the transmission oil cooler piping
- Adding LiquiMoly TopTec 1800 oils for the gearbox
- Test drive after repair
The work is estimated to last two days.
And this remains to be seen.
Arto
 
Also if they use the ecu that comes with the gearbox it will need resynced to your immobiliser,
 

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