I don't know if this may help in / confirm your decision. It comes from the ZF publication, "Manual transmissions, double-clutch transmissions and automatic transmissions for cars".5. Maintenance recommendations ZF automatic transmissions

3/4-speed automatic transmissions:

ZF 3 and 4-speed automatic transmissions must be filled with approved ATF oils according to ZF list of lubricants TE-ML 11, lubricant class 11A / 11B or with mineral ATF oils according to the former Specification Dexron II / Dexron III by General Motors. For oil-change intervals consult the vehicle manufacturer's specifications.

5-, 6-, 8- and 9-speed as well as 4HP20 automatic transmissions:

ZF 5-, 6-, 8- and 9-speed as well as the ZF 4HP20 automatic transmissions are filled maintenance-free with specially developed semi-synthetic ATF oils. However, due to the many factors influencing the service life of transmissions in individual operation, ZF recommends an oil change after 150,000 km for its transmissions. In operating conditions with high temperatures and loads, or with unknown vehicle use in the past, it can make sense to change the transmission oil at shorter intervals.

In each case, only released ATF oil may be used for oil changes. And oil changes must be performed in accordance with the relevant specifications. The exception is the ZF 5HP18 automatic transmission which must be filled differently depending on the version.

The released ATF oils in each case are specified in the ZF Lubricants List TE-ML 11. Please consider also the service specification of the vehicle manufacturer.

When a new, to us, Jaguar arrives in their new home here I immediately change the transmission pan, gasket, filter, oil and make sure I use ZF approved transmission oil by specification as I do not know how the transmission was treated nor what was possible added to, or replaced by, the previous owner. I have done this with all of the ZF 5 & 6 transmissions that are in the cars I own and never had a problem.

The fun part is always filling the transmissions by the questionably located filler port on the side. Not much room to work there even with the special tool.

 

My special tool, $10.00 garden weed sprayer/transmission fluid refiller. Its not rocket science. Just place a wet towel around the exhaust near the fill hole if you don't want to burn your fingers.

 

So, in contrast to the documents quoted above, no time-based change interval specified by ZF?

Richard

 

I'll go with this recommendation any day!!
"In operating conditions with high temperatures and loads, or with unknown vehicle use in the past, it can make sense to change the transmission oil at shorter intervals."

 

That is correct Richard. I have not been able to find a date specific reference in the ZF database of service documentation. There may be one somewhere, but I have not been able to find one. The only obscure reference to milage that I found in a German document was in regards to "strenuous or demanding driving conditions" which was not defined, indicated the time-interval between fluid changes should be "more frequent", again not defined. I have found ZF to be excellent in their documentation and very precise, so I find the lack of definitions in driving style and frequency to be out of character. I would like to ask the engineers what they do? I'll bet some of them drive interesting cars and possibly under demanding conditions!

 

XKRAU, nice special tool!

I wish I had thought of that before spending a bit more, on a fluid transfer contraption with multiple attachments. The towel is an excellent idea since we have to bring the transmission up to operating temps to check the fluid level. The burned back of my hand will appreciate the advice.

 

May this will help. Last sentence.

 

That's very appropriate as a general recommendation. However, in the case under discussion, the car has done 11k miles which I wouldn't call "unknown vehicle use" but would call "virtually no vehicle use". 🙂

Richard

 

Get one of these add-a-drain-hole, keep the pan installed when draining fluid:

 

Surely the X150 already has a drain plug in the sump?

Richard

 

Uh, nope.

 

Uh, yes there is actually...have another look at the pan...

 

There isn't one on mine. Nowhere. Not anywhere.

 

Is yours original? All JLR's I've got here have them.

 

The one that I had replaced didn't have one as I checked specifically. I checked again and the one I bought to replace DOES have one, same as above. Maybe my Trans was serviced for the CPO before I bought it? I don't know. The paperwork is long gone.
Either way, if someone replaces the pan/filter with a pan that DOESN'T have a drain, it may be wise to install one. Or get a pan that already has a drain. Like evidently I do now. My bad.

 

Well I reckon yours may be an exception or at least proof there’re some without drains but the service manual advises removing the drain plug to drain the transmission prior to service so most pans and vehicles surely have them.

 

As Jahummer states the OEM transmission pan filter made of mostly plastic has a drain plug. You might be thinking of the 4.2 diff which doesn't have a drain plug.

Doing the maths, a couple of hundred bucks for a transmission service compare to a couple of thousand bucks for a possible transmission rebuild down the track. No brainer for me.

 

My 2 cents on the subject is on my 2010 XKR has a the tranny fluid changed 3 times during my ownership. I now have 202,000 miles on the original ZF, and it still shifts fine. I have had it done approximately every 65-70,000 miles. I have never owned a car with an automatic transmission that has gone this amount of mileage without a rebuild or a replacement. Every Chrysler product I've owned, the transmission broke down almost literally on the 60,000th mile. On my Buick Enclave, I've had five transmissions, none of which lasted 10,000 miles.. 18,500 km sounds a little premature to be doing it. I would stick to the 60-70,000 mile intervals.

 

From the ZF documentation "Depending on the driving style, ZF therefore recommends a transmission oil change every 80,000 to 120,000km or after 8 years at the latest."

Pretty straight forward to me.

 

I have a 1994 XJS 4.0 coupe with 222k miles and original ZF4 tranny. I replace the fluid every 30k miles. Its amazing how well theyre built and long lasting when maintaned. I also own 2 other cars with the ZF6 and they both have drain plugs. I prefer to drain and refill those every 20k miles since its no big deal. Its not what everyone does so, but I demand performance from time to time from my cars.