Whilst towing my caravan from essex to oxford on friday i lost 4th and 5th gear .I tried to change gear manualy but to no avail the gear numbers came up on the dash but it did not change gear after the car had cooled for a couple of hours all seemed fine.
Untill the return journey today i only made about 20 miles before it happened again it was a recovery job home as to drive another 100 miles in 3rd gear would have done all sorts of damage.
On arriving home the car drives fine again anybody else had this prob as its a 4.4 i wouldnt of thought the caravan would make any difference but it seems to as with no van behind everything is ok.
The RAC man seemed to think the gearbox oil filter could be the problem any ideas.

I had the same whilst driving "enthusiastically" back from Wales with lots of manual shifting. Basically the gearbox overheated and it wouldn’t go over 3rd gear for about 10 minutes until it had cooled down.

I had the gearbox oil and filter changed within a week, because ATF fluid degrades massively if it overheats. It is a Sealed For Life unit, which actually means it won't fail until the life of the warranty is up, but go to a transmission specialist rather than any garage or dealer.

Do you tow in Sport mode? This is kinder to the gearbox as there is less slip from the TC, it is also better for the engine to rev higher than for it to labour on hills.

I would also have the cooling system flushed as the engine coolant passes over the trans radiator and it can silt up.

Extract from Manual:

Cooling Strategy
The purpose of the cooling strategy is to reduce engine and transmission temperatures during high load conditions, when towing a trailer for example. Under these conditions the engine and transmission may generate excessive heat.
When in any gear other than 5th or when in 5th gear at a speed of 38 mph (61 km/h), if the transmission fluid temperature increases to 124C (255F) or higher, the EAT ECU employs the cooling strategy. The strategy uses a specific shift and torque converter lock-up clutch map. This map allows torque converter clutch lock-up and gear shifts to operate outside of their normal operation. This will reduce the engine speed and/or slip in the torque converter, therefore reducing heat generated by the engine and the transmission.

The cooling strategy is cancelled when the transmission fluid temperature decreases to 120C (248F) or below.

Click image to enlarge

Cheers for that Dan a friend of mine has a workshop and also the same car so it will be done this week he is also doing his as he was under the impression that the box was sealed for life just goes to show you learn something every day

as dan says change the fluid and strainer and flush the coolent system thru , also check the brakes on your trailer / caravan are releasing properly  onto no6 Range Rover

Everyone needs a hobby

speedymarktd6 wrote:

also check the brakes on your trailer / caravan are releasing properly

I drove 100 miles with the handbrake full on on my c'van, didnt even notice (although I did roll my eyes at the single figure mpg) untill I pulled into the service station and saw the smoke!  

flush gearbox, new filter, new oil and add this one:

http://www.lubegard.com/automotive/trans_atf_platinum.html

you will have a new car... XJC, RRV8, Series1 86 and 107% of real pleasure

delsilencio wrote:

flush gearbox, new filter, new oil and add this one:

http://www.lubegard.com/automotive/trans_atf_platinum.html

you will have a new car...

You will need a new car, or a new gearbox at least.

Never deviate from recommended fluids in a ZF Gearbox. 

" You will need a new car, or a new gearbox at least.

Never deviate from recommended fluids in a ZF Gearbox "


Who said that? Land Rover? They also speak about liftime oil filling of gearbox.....

Had the same problem with overheating gearbox and running electronically managed into the emergency mode several times during my holiday in your Highlands.

Was at ZF Service in Dortmund ( http://www.zf-dortmund.de/ ) for a great service : cleaning, spoiling, renewing of some small springs and ball valves, rubberrings, gaskets, new filter pan refilling with new oil, electronically testing etc... and have had a long talk with the leading workshop engineer....

Sump, filter pan off and beginning to loosen the valve block