That's a total load of ...you know what!!! seriously. Yes its lifetime fluid for 80,000-100,000 miles then your box dies, Ive been to ZF whom make the boxes so why would they change the fluid ???? My visit at ZF Dortmund for Gearbox maintenance.(very, very long!) HUGH RESULT!!
Here are my instructions, which obviously wrote from watching the whole process in the in the ZF workshop:
To change auto gearbox Fluid and filter on an E38 you will need:
1) a torx T20 socket for the pan screws and filter screws (male)
2) a H8 Hex socket for the drain and fill plug (male)
3) a minimum 7.5ltrs Fuchs TITAN ATF 4000 or Esso LT 71141
4) a new filter ( BMW )
5) new pan gasket ( BMW )
6) a garden sprayer ( to refill, works brill )
7) a suitable container for draining fluid and rags.
> car up minimum 400mm
> Start up.. 10mins turn off
> remove bottom plug and drain fluid / BEWARE HOT FLUID BURNS !! / safety goggles required
> replace pan plug
> remove all pan screws / clips that hold wires to the pan/ be careful there will be fluid still in the pan!!
> remove the 2 filter screws / there will be fluid left in the filter !!
> clean out pan and the four magnets/ lint free cloth / degreaser or brake cleaner
> clean surfaces for gasket
> screw in new filter / make sure its in flat and take care to get the 'O' ring in correct
> replace the four magnets
> place gasket on pan with a little fluid / replace pan
> Undo fill plug / drivers side rear
> start filling until fluid dribbles out / replace plug finger tight
> start car... go through all gear selections slowly 3 times keeping foot on brake / then in 'P' turn off after 10 mins
> undo filler plug fill some more until dribble comes out / plug back in finger tight
> Start car put in 'N' ....now be careful not to burn yourself!! whilst car running (Air-con on full blast) undo filler plug put more fluid in until it dribbles out again, put filler plug in and tighten.
> All done car down, fluid to a designated place!!
> Time for a cup of tea / can of beer or a ciggy
Note: the entire box takes 10 ltrs, but you will not require this as the torque converter will still be half full and also the valve control body also contains more, I would say that a 7.5 ltr can will be enough, but please don't quote me!!
As for your shift problem when cold.......this is easy....but your bmw mechanic should have told you this the EGS and ECU work together, so when cold it will not let you race through the gears 1 & 2 until the ATF has reached temp and the EGS has determined the correct temp has been reached ( safety feature), if you start your car and let it idle for say 5 minutes you should see a difference, if not go back to your friend and ask him to reset the EGS adaptations, if this doesn't sort it I would say check the fluid level is correct as per fill instructions above.
Oh...as for the Squeak that will not be coming from inside the box....mounting maybe..definetly not the box.....
Just to add....Ive now changed mine 3 times with no ill effects and Ive also guided over 50 people in doing the same with no problems...but if it continues after the above..get back to me by PM its easier to find than searching through the forum.