zf transmission fluid change
 

Ok, i know this has been covered before and that alot have used alternative atf fluids to the Mopar fluid or Lifeguard 8 which Jeep recommend such as Penrite BVM or the Nulon fully synth low viscosity atf.
My question is, as Penrite recommend not mixing their oil with other stuff, how many actually flush the whole transmission and replace the whole 8 litres ?
Seems to me, most of us are just dropping the pan and replacing the 4.5 litres
that comes out.
The other thing which is interesting is i recollect reading a zf document stating
full flushing of the box was not recommended.
Thus leaves us with 2 two options, either refill the box with Mopar / lifeguard 8 oil
or take a chance and mix the oils??

All tranny oils say do not mix but I have been for many years, quite a few boxes now you cannot do the old style flush out routine, more like DON'T than not recommended............... The proper way to get rid of all the oil is in the WSM but since most DiYers don't have a hoist they just do the half change, to date I haven't heard anyone having any dramas with different oils, the problems stem from not refilling properly if you don't do it right you won't get enough in the box... mine has had a couple of changes with BMV and now its Nulon all good, I also suspect many tranny changes aren't full oil swaps either as its a pain to do .... I would guess Mopar is Lifegard .

The vehicle needs to be level when you change the oil and it pays to drill some holes in the cross member so you can remove the front bolts easily, make sure you drill the holes when the vehicle is level not just the front lifted up or the holes won't line up when you go to drop the pan.... T40 head is needed I have a long T bar one as well as a socket head for the torque tool.

The key point for half flush in lay terms from reading wide is oil has a cleaning effect and a full flush may be too good in doing its job by potentially dislodging chunks of stuff so the risk is you may end up with a valve blockage or something similar for your troubles. Obviously the older and longer k's this would increase the risk. Also from a few changes and reading the slightly different approaches to setting the oil level is that the imperative is to have sufficient oil at the end of day, a tad over by a good i.e a couple of hundred mils is not going to cause foaming etc. There is a lot of use using aftermarket oils world wide in BMW's Landrovers all using this box and brand mix is not on the list of concerns. I'm on BMV as cheap on special and is certainly popular across many brands.

From what i gather the Mopar 8&9 atf is the same as the ZF Lifeguard fluid8.
They both look and smell the same.
The Mopar atf is about $150 a litre - absurd price, Lifeguard 8 about $50 a litre.
As Penrite and Nulon now have alternatives you would think Jeep would make the price of the Mopar stuff realistic !!

I ended up picking up the Mopar NV245 for the transfer cases real cheap.
Any recommendations for the diff oil ?

I use Penrite ATF FS in the TC... near 2 lts

Diffs get Penrite Pro gear 75W85 GL5 I don't have ESD, front 800mil/Rear 1.1lts

Power Steering gets Penrite LDAS which is the only alternative I have found to the Mopar stuff...


If you fill the tranny correctly you can't get the level wrong, I pump in about 3 lts till it dribbles out then fire up the engine and top up the last bit, when it dribbles out the hole replace bung, check chocks and brakes on, run through reverse 5 sec and 2nd gear 5 secs then neutral and rev to 2000rpm, 5 sec, engine at idle in Park, remove fill plug, oil should dribble out then its full..... oil temp should be under 30c..... easier if you have a hoist though... I have mine on 110mm ramps under all 4 wheels (made of pine garden sleepers) big chocks and door left open so it locks in Park when underneath.... I always have 8 lts on hand in case I stuff something up, which I have found the hard way is a sensible idea..... Its a slightly modified version of what the WSM says, it usually takes in 4 lts... Don't shut down engine without fill plug fitted or it will drain out...

For diffs and transfer the Nulon squeeze bags are a game changer I reckon. Make it so easy to do.

Just did the rear diff, your right about the Nulon squeeze packs,makes it very easy.
Now to see if i can get under the car for the front diff.
Got ramps but the car needs to be level i guess so might be a bit tight??