Hi all,I have a Range Rover 2003 4.4 petrol and now and then it decides not to change above 2nd gear normally when I run about town and the engine is a bit hotter,if I stop for a few minutes and switch off the engine then start it up it’s fine again it also happened when towing a caravan.Would an oil and filter change solve this I have already changed the radiator.Any help on this matter would be greatly appreciated.
 
As above, check oil quality and also consider changing the Gearbox Oil Cooler if it mainly happens when it is hot.....(The gearbox has a cooling strategy to hold lower gears to force more fluid through the cooler to keep box temps down!)
 
From what I've read on Dave Ashcroft's site (https://www.ashcroft-transmissions.co.uk/frequently-asked-questions/4hp22-faq-s.html) a dirty filter can give these symptoms as can a sticking governor valve, both signs of old dirty oil or debris in the oil. It should be cherry red; if it's black or dark with a burnt smell if definitely needs changing.
Thanks for your reply I will get a service kit and change the oil anyway won’t do any harm
From what I've read on Dave Ashcroft's site (https://www.ashcroft-transmissions.co.uk/frequently-asked-questions/4hp22-faq-s.html) a dirty filter can give these symptoms as can a sticking governor valve, both signs of old dirty oil or debris in the oil. It should be cherry red; if it's black or dark with a burnt smell if definitely needs changing.
Thanks for your reply I think I will change the filter and oil anyway it do it any harm.
 
One thing mentioned on the Ashcroft site is a sticking problem after changing the oil and filter, but it occurs when cold rather than hot:

I have a 4 speed ZF Auto and it sticks in first gear in the morning or when cold and is reluctant to change up from 1st gear. Once the gearbox has warmed up it shifts normally. Why?

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs.

I've also heard that regular oil/filter changes are ok if the box has been well maintained in the past, has not overheated or been abused.
Problems start when someone buys a second hand box which has not been well serviced (or at all) and may have gotten too hot; they change the oil and filter and the ATF loosens and stirs up old residues which then clog the filter or the governor.

But as @Saint.V8 says if it's sticking when hot it might be something else such as inadequate oil box cooling delaying up-changes. As above, I'd change the oil/filter unless you know it was done recently i.e. last 30K miles.
 
One thing mentioned on the Ashcroft site is a sticking problem after changing the oil and filter, but it occurs when cold rather than hot:

I have a 4 speed ZF Auto and it sticks in first gear in the morning or when cold and is reluctant to change up from 1st gear. Once the gearbox has warmed up it shifts normally. Why?

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs.

I've also heard that regular oil/filter changes are ok if the box has been well maintained in the past, has not overheated or been abused.
Problems start when someone buys a second hand box which has not been well serviced (or at all) and may have gotten too hot; they change the oil and filter and the ATF loosens and stirs up old residues which then clog the filter or the governor.

But as @Saint.V8 says if it's sticking when hot it might be something else such as inadequate oil box cooling delaying up-changes. As above, I'd change the oil/filter unless you know it was done recently i.e. last 30K miles.
Could be a good shout
One thing mentioned on the Ashcroft site is a sticking problem after changing the oil and filter, but it occurs when cold rather than hot:

I have a 4 speed ZF Auto and it sticks in first gear in the morning or when cold and is reluctant to change up from 1st gear. Once the gearbox has warmed up it shifts normally. Why?

We have noticed many customers reporting this fault starting a few days after an oil and filter change and after researching this using our experience and the expertise of others in the trade we have come to the conclusion that as ATF oil is a detergent type oil, when the oil is changed this will dislodge and stir up settled debris in the autobox which in turn jams the governor valve. In light of this although it sounds controversial it is debateable if changing the oil and filter is a good idea, some say if the box it going to fail it will fail if the oil is good or bad and their advice is leave it alone. I am still undecided but the truth is I get a lot of calls from customers thinking they are looking after the autobox by servicing it and a few days later this fault occurs.

I've also heard that regular oil/filter changes are ok if the box has been well maintained in the past, has not overheated or been abused.
Problems start when someone buys a second hand box which has not been well serviced (or at all) and may have gotten too hot; they change the oil and filter and the ATF loosens and stirs up old residues which then clog the filter or the governor.

But as @Saint.V8 says if it's sticking when hot it might be something else such as inadequate oil box cooling delaying up-changes. As above, I'd change the oil/filter unless you know it was done recently i.e. last 30K miles.
could be a good shout might look into this a bit further in case I open up a can of worms..

Thanks
 
Transmission fluid overheating (and the resulting selection of cooling strategy mode by the transmission ECU to inhibit upshifts) is generally caused by restricted flow in the radiator (which you have replaced) or the oil cooler. A faulty fluid temperature sensor is another possibility. You really need to determine whether the fluid is overheating or not, or if the temperature sensor is faulty.

Temp%20sensor%20close_zpset7szos6.jpg


Temperaturesensor.jpg


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TOTcharacteristic.jpg


Phil
 

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