when to do first change of 4 wheel drive fluids on 2011

[JasperEdwards]

I just acquired a 2011 EX35 Journey AWD and it is just about to get to 13,000 miles. The dealer doesn't want to do any maintenance on any of the 4 wheel drive fluids including the transmission until 60,000 miles which I think is way too long, especially for the first change. However, I may be able to get them to do them at 30,000 as part of the premium maintenance package. However, I think even that is too long for the differentials because I remember my Acura MDX needing differential fluid changes at both 7500 and then again at 15,000. My goal is to try and maximize the car's ultimate life while also keeping the warranty intact. Am thinking about using Amsoil in both differentials and doing that pretty soon. Also, for engine oil, there is a time element as well as a mileage element, and I'm wondering if that same consideration also applies to transmission fluid. If this car had seen normal miles, it would already be due for the transmission fluid based on the time element and so I'm wondering if I really ought to try and get the trans done well before 30,000 given the time element. All thoughts and experience will be most welcome.

[NJGuy]

As you know, there are many different thoughts on fluid change intervals for a differential. Some say to do it 'early' to get rid of all the break-in material. Infiniti isn't very clear as far as set intervals, but according to what they've published, the differential fluid (and others) do not necessarily 'require' replacement. My opinion falls somewhere in the middle of these two philosophies. I'd say just change the fluids at whatever interval you're comfortable with. And other than the ATF and transfer case fluid (which I've already questioned), the fluids for the AWD system aren't anything special. So you're not bound to the Infiniti dealer for those fluid change services.

The 2011 EX has the 7-speed auto, correct? I don't believe that this transmission designed to be 'serviceable' and is supposedly sealed. It might be possible to change the fluid in the 7-speed, but I personally haven't seen any procedures yet that show how.

By the way, I don't think you can compare the MDX rear differential to the that of the EX. The EX is RWD based and uses a conventional differential design. I'm not intimately familiar with all of the technical details, but I think the EX uses Nissan's ATTESA system for controlling power distribution to the wheels.
The MDX, on the other hand, is FWD based has a much different rear differential. I don't know which system your MDX used (VTM-4 for first Gen, SH-AWD for second/third Gen), but I believe those systems use some type of electronically controlled wet clutch to distribute power to the rear wheels depending on the conditions.

So essentially comparing the differentials of the MDX and EX is like how the saying goes, "comparing apples to oranges".

[JasperEdwards]

Thanks very much. You are correct about the 7 speed being sealed. And, I did some further research and it is actually designed to be "serviced" every 30,000 miles AFTER the first change at 60,000. I still think that is backwards, that after you get the initial break-in material out at 30,000 that you could probably go 60,000 between subsequent changes. You are also correct about the differential on the MDX being totally different. Somehow, I had forgotten how different they are. I had a 2003 and it required a unique to Acura/Honda VTM4 fluid and there were electro-magnetic clutches in there that decided when the rear wheels would get power, and the system was designed so that almost all the time it was running in front wheel drive mode. I don't know much about how the Infiniti system works except that it mainly runs in 2 wheel drive until some sensor decides that the fronts need some power.