Changing ATF fluid after ages...
Discussion
From the reading I've done, the general consensus if it's gone that far let it be.
Often friction material gets caught up in the oil, so new oil will cause the box to slip. In addition to that, some dirt and rubbish is just sat nicely in little nooks and crannies. ATF is a detergent, so can cause some parts that function properly as is to fail shortly after.
I'd leave it until the box has had it, and then have it sorted properly.
Often friction material gets caught up in the oil, so new oil will cause the box to slip. In addition to that, some dirt and rubbish is just sat nicely in little nooks and crannies. ATF is a detergent, so can cause some parts that function properly as is to fail shortly after.
I'd leave it until the box has had it, and then have it sorted properly.
I'd take a look at the oil - is there a dipstick on that trans?
If there's any metallic particles in it then the below applies imho (i.e. friction material is suspended in the fluid), otherwise I'd give it a change.
If there's any metallic particles in it then the below applies imho (i.e. friction material is suspended in the fluid), otherwise I'd give it a change.
JakeT said:
Often friction material gets caught up in the oil, so new oil will cause the box to slip. In addition to that, some dirt and rubbish is just sat nicely in little nooks and crannies. ATF is a detergent, so can cause some parts that function properly as is to fail shortly after.
Appreciate this is for the ZF box in the Range Rover Classic & P38 but this is Ashcroft Transmission's take:
Q. 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?
A. The governor valve is sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary it replace your Autobox.
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."
https://www.ashcroft-transmissions.co.uk/frequentl...
That said, if you are having problems then a fluid & filter change is worthwhile as you would have nothing to lose.
Q. 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?
A. The governor valve is sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary it replace your Autobox.
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."
https://www.ashcroft-transmissions.co.uk/frequentl...
That said, if you are having problems then a fluid & filter change is worthwhile as you would have nothing to lose.
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