Finally, what with the bad weather, got the ATF changed. Have posted pics on link below. First pic is vehicle on homemade wooden stands as previously posted.
These gave a height of around 8inches which I found sufficient. Pics of the pan before and after cleaning. There are reports of the original torx screws, 21 in total, that fasten the transmission pan to the housing being very hard to remove, and indeed it can be so. My solution was to use a heat gun, not a blow lamp or you will damage the pan as it is plastic. After heating up the heads of the screws they come out fairly easily. I decided to replace with 6mm hex screws easily available using 2 washers. Much cheaper than buying 21 modified screws from Jaguar. I did not use grease on the replacement screws. I did not follow this for 2 reasons, firstly the original screws had a thread locking compound on them and secondly how often is one going to take this pan off? I used locktite on my screws and with the hex heads should have no problem in removing screws if required in the future. The fluid I removed was in reasonable condition no smell of burning etc. The fill/level plug needs a fair bit of force to remove, using the cut down 10mm hex key which an extension on it. Getting the new fluid in is let us say awkward but I found the arrangement of using the hand pump, costs around £15, with a good diameter pipe and the 15mm copper plumbing fitting works well. The sump can be filled quickly and without loss of too much fluid.
Flushing of transmission as follows. Run engine until at temp then open drain plug , note how much fluid drains out. I then removed the pan and noted quite a bit of fluid still dripping. Replaced pan and waited until next morning. Removed pan again and found around 0.5L of fluid in it. Total fluid removed was around 6.5L Pan was then cleaned up and filter flushed in reverse direction. Nothing of note seen on flush fluid so assuming filter in good condition. On good advice changed the electrical socket sleeve, apparently the original prone to leaking though mine was ok. New one has black "O" rings compared to original orange ones, cost was around £7 from Jaguar. Seems pointless not to change it because if it does start leaking you need to drain the fluid to change it anyway.
Anyway with that completed was time to fill up. Now ZF say that the fluid level is critical but frankly I am not convinced. To my mind as long as the fluid level in the sump cover the inlet to the the filter, and hence the feed to the pump thats ok. I did a short experiment to test using my replacement fluid, Millers ATF DM. ZF state that you check fluid levels at between 30 degC and 35degC, then at 40degC to 50degC but not exceeding 50deg C. Well I placed a small amount of the fluid in a test tube and heated it up. I used 100mL of fluid at 30degC, at 70degC there was possibly a marginal increase in volume. Reading what ZF state you would think there was a massive increase in volume, not so. And one final note if the level is so crucial what happens when going up or downhill and around cambered bends? All the details of how ZF would like you to adjust the fluid level is available on their website.
I digress anyway back to filling up. I followed the procedure of filling the pan until fluid starts to drip out, approx 3.5l. One then starts the engine, this pumps fluid around the transmission allowing more fluid to by filled, approx another 3L. One keeps the engine running until the fluid reaches approx 40degC, ZFs recommendation. At this temperature fluid should stop dripping out of the fill hole . if nothing drips out put more fluid in until it does and monitor temperature again, if fluid does drip out leave it until it stops dripping keekping a watch on the temperature. In my case it took around 15 minutes to get to 40 odd degC so no rush. I used a multimeter with a temperature wire placed inside the transmission monitoring the temperature of the fluid flowing out.
When I was satisfied re fluid level I replaced the fill plug. there is a recommended torque for this but what tool one is supposed to use is beyond me as there is only room for the cut down 10mm hex key. Anyway using this and the extension used to remove it originally I gave it a good tightening up.
What I did subsequently discover was that I had a slight leak on one of the transmission pipes going to or from the radiator. Apparently this is quite a common problem, not usually noticeable as the underbelly pan catches it. How long this had been leaking I do not know, but what I do know was that on removing the under belly pan it was very oily. Now Millers ATF DM is red in colour where the ZF fluid I believe is a light gold colour similar to engine oil.
The recommended fix for this problem is to replace the pipe!!! Sorry not in -10degC temperature. It is a complicated and time consuming performance as the pipe threads its way around the engine compartment. Mine was leaking from the bottom radiator connection pipe whoise connection at the radiator isn't even visible from underneath. A top hose leak will be much easier to fix as one can get at it easily. My solution was to clean up the "swaged" connector which was the source of the leak with meths and then used "super steel" a 2 part epoxy adhesive to plug the leak. As a belt and braces fix I then applied "kraken" tape as best I could. So far no leaks, I will check this again in a few weeks just to be sure. And finally I added oil absorbing mat to the underbelly pan to ensure that hopefully nothing escapes from it. Again this will be checked in a few weeks as it needs to come off the check my joint seal.
I don't think I have missed anything only to say that the transmission seems fine, not that there was a problem before but hopefully this exercise will forstall any possible problem.
Pics of my escapde are at http://s777.photobucket.com/albums/y.../ATF%20change/

 

Well done very imformative. What year and engine and what determined your need for a trans flush? Was it age, mileage or something else? I like your temperature/volume test curious what the techs might add. When finished did you notice how exact was the amount drained vs added? What did the flush cost you? Thanks again.

 

Not a believer in this sealed for life story. always changed ATF in all my vehicles. Didn't have problem before and not got one now. Think amount used about same as changed, but flushed twice so all new fluid. Cost was £80GBP using Miller ATF DM a supposed equivalent, A few guys in UK have used it and all ok. Millers state equivalent. The £80 GBP bought me 20L enough to do the two flushes and a refill. Is a 2004 3.0L V6