We in the auto industry off the information provided from auto manufactures tend to agree that the LIFETIME represents the WARRANTY period which for most auto manufactures drivetrain represents 100K miles with all no or at least very few exceptions.

The other common sense is that all new assembled parts that have frictional contact will shead a least small amount of material during the initial break in period. So here again common sense is to change ALL fluids at a reasonable mile which IMHO based on hundreds of problematic fluid lubricated parts is no more than 15k miles.

It's not a debate or what some claim having gone years and record miles without issues (that they know of) but your large investment in your new vehcle or used which in this economy is very high!

 

I've found that to get the transmission fluid changes pretty much requires doing it yourself or using an independent mechanic though. Many, if not most, of the dealers just won't do it because it is "lifetime."

 

I am not sure this is accurate because there is no service advisor not to do it. And as I often post most all dealerships worldwide are still and independent business they can except and do any service work that is not necessarily listed by the auto manufacture as long as there is not the exact wording not to do the service during a warranty period. In which I personally have never seen that's not saying there may be that somewhere in some year on some platform for some model etc. LOL ???
This is pretty much the same thing as someone bring in their vehcle 1000 miles before a scheduled in the service advisory before a engine oil; and filter change and dealership saying to that customer "sorry you have to return in 1000 miles before we can do that service" !
Or how about all the recommend services that dealerships offer NOT on the require service under the WARRANTY?
I can see a service writer saying why do you want that it not needed because it is a lifetime no service needed. But a smart owner would "what is exactly lifetime represent and does that mean as long as I own the vehcle forever , may I see your answer in writing. Good luck with that....never going to happen.

If a dealership does not want to do a service, there are countless well qualified independent service shop that will and are proven less costly and WILL NOT VOID any existing WARRANTY. At least in the USA. Moss warranty acts states as much!

We service many outside the recommended or no service required service recommendations during warranty periods for customers all the time..

 

In this area, I checked with three Jeep dealerships and two Mazda dealerships when I felt it was time to change the transmission fluid. All five refused to do it. Luckily, I have a good shop with certified mechanics that I trust and which has given me good service. I've pretty much given up on going to the Mazda dealerships for service and go to the one Jeep dealership that I trust more than the others because the Jeep is under the lifetime Chrysler service contract which, over the years, has saved me significantly more than it cost.

 

23 CX-5 Carbon NA. Drained and refilled both Dif and Xfer case lube at 5K. This is a picture looking down into my catch container (red plastic Folgers coffee container). Notice: 1 the light colored swirls and 2 what a small volume of lube drained out. This is all the evidence necessary for me to do this and to do it regularly. Cheap and easy peace of mind. The only annoying part for me is that all the drain and fill bolt heads are not the same size. haha

 

 

Nice fluid pic Tom&Max. Perhaps I'll add mine when I get the job done.

Related topic - washer size for the Xfer and diff drain & fill bolts? I have found OEM part #9956-41-800, an 18mm aluminum washer used for all 4 bolts (2 drain + 2 fill).

Agreed? I'm about to order a supply probably from Amazon or NAPA.

 

This is always a good idea to have them around. You cant imagine how many think its ok to reuse a drain plug washer?

My suggestion is NAPA so you can look at them. I have ordered a couple times drain plug washers from Amazon and even Ebay and the punch cut is rough and not symmetrical.

 

When I did my fluid change I measured the factory washers. I suggest if going to a retail store take a cheap plastic caliper with you and measure to ensure you get home with the right size. My scrap cardboard filing system with measurements attached for factory washers.

 

So, to recap what is needed for AWD differential fluid change:

Aluminum washers: set of 4 x 18mm inside diameter, 2 for drain plugs + 2 for fill plugs; OEM # 9956-41-800 for reference (see Tom&Max pics)

Fluid: 75W85 hypoid such as Mazda SG1 or quality brand equivalent 75W85 hypoid gear fluid (I use Redline, there are others); 0.45 L ~ 0.48 US qrt for front transfer case and 0.35 L ~ 0.37 US qrt for rear diff; total just under 1 L or 1 US qrt per total change (see Lobstah & Rodster posts)

Tools: 24mm socket for drain, 23mm socket for fill, sometimes access is tight, might need short socket or even a closed socket wrench, drain bucket of course, dispose of properly, and a fluid transfer pump to pump fresh fluid in from the bottle is helpful. Can't really pour a bottle in.

Torque for Drain and Fill plugs: 39 ft lb = 52.8 Nm, easily accomplished with "snug" hand-tightening

Frequency:
- good suggestion of first 15K miles = 24K kms after brand new purchase
- personal choice thereafter, each 30K - 60K miles = 48K - 96K kms, dependent on driving habits and conditions; heavier “severe” use such as regular towing, off-roading etc will require more frequent changes (see Callisto & Lobstah posts)

Best Practice tip: always remove fill plug bolt first to make sure it can actually be removed, it is the higher of the 2 bolts; because if you remove the drain plug, drain out fluid then, cannot remove the fill plug, it's basically impossible to refill the diff or transfer case.

Bonus info:
- for engine oil and transmission fluid changes, washers are 14mm inside (Tom&Max pic post), OEM #9956-41-400 and regardless of owner manual stating “lifetime” transmission, fluid and washers should be changed at least every 100K miles = 160K kms; use genuine Mazda ATF, worth it; also not a difficult job.