Good evening everyone, it is that time again, 170km - this will be second drain and fill since I got the car 8 years ago.
Is it ok to use this or should I stick with LifeGuard 6
thank you in advance. Yea he kicked *** here at the FALLSVIEW CASINO

It is a personal decision---after checking out various threads on the X350 forum and various others I am happy to use it.

The early Lincoln Navigator 6 speed transmissions were made by ZF in Germany in the same facility as Jaguar's and likely filled with the same transmission fluid.

Check the information available and then decide.

I've run Mercon SP in my 2005 S-Type 3.0's ZF 6HP26 since November 2014. Currently at 93,600 miles, the car shifts smooth as silk upon each and every upshift/downshift with no hint of the infamous "ZF squawk". After doing copious amounts of research for years prior to making the switch, I decided Mercon SP was my fluid of choice and have not regretted that decision at all. Do your own research, make your own choice, and change your fluid. The key to keeping these ZF units going is indeed fresh ATF at frequent-enough intervals with some ZF experts recommending every 30,000 to 40,000 miles....

I agree with Jon89. I just drained and filled this weekend using mercon sp. Shifts great and no more surging while driving in the morning.

Thank you for the advice! Have a great night guys

Me again everyone! One more question! When it is drained, I have read only about 6 liters comes out roughly, is it ok to mix in this with the LIFEGUARD6 that is currently in there?
This will be my second change at 170 000 km.
Car still runs perfectly

It should be fine ! I swapped from zf-6 to totul fluid !
And mixed whatever was left in the torque converter as there realy is no easy way to get it out ! Mine works perfectly as far as I can tell ! Or at least exactly the same as it did befor the change !
I did find that with the front of the car jacked way higher than the rear and turn the engine over momenterely there was a sweet spot the engine may or may not stop at that drained another 500mls , so my amount drained was 6.5liters .

I also mixed. Note that Mercon SP has a red coloured dye--so you can spot any leaks!!

Yep . totul 6 fluid was also red!