2013~2016 Question on CX-5 Rear Diff fluid change

[wlong01]

Last time I had my 2016 into the dealer I wanted to get a drain and fill on the ATF and transfer case. The dealer talked me out of the ATF change this time (only 40k on odo) but went ahead with the transfer case (or so I thought). They did a rear diff change by mistake.

Question - when they do a rear diff fluid change service do they also change the transfer fluid since it's the same fluid? I didn't think to ask at the time.

 

[yrwei52]

Usually they will do whatever they stated on the invoice. The best way to tell is to check your invoice.

 

[wlong01]

Usually they will do whatever they stated on the invoice. The best way to tell is to check your invoice.

I did, it just says Rear Diff service. I guess I have to assume they didn't do the transfer case and fight them next time I go in that they owe me a TC fluid change since they did the wrong service.

 

[madar]

I did, it just says Rear Diff service. I guess I have to assume they didn't do the transfer case and fight them next time I go in that they owe me a TC fluid change since they did the wrong service.

The diff service is more beneficial anyways. Not much going on in the transfer case.

 

[yrwei52]

I did, it just says Rear Diff service. I guess I have to assume they didn't do the transfer case and fight them next time I go in that they owe me a TC fluid change since they did the wrong service.

Another way to find out is how much gear oil SG-1 the invoice stated. It should be around 0.7 ~ 0.8 quart for rear differential. If it stated 1.2 ~ 1.3 quarts, either they did front transfer case gear oil change, or they just over-charged you.

 

[yrwei52]

The diff service is more beneficial anyways. Not much going on in the transfer case.

Yes, on the CX-5 and all current Mazda i-Activ AWD system.

The only exception on Mazda vehicles is the gen-1 CX-9 (2008 ~ 2015) and frequent FTC oil change is necessary.

 

[wlong01]

Another way to find out is how much gear oil SG-1 the invoice stated. It should be around 0.7 ~ 0.8 quart for rear differential. If it stated 1.2 ~ 1.3 quarts, either they did front transfer case gear oil change, or they just over-charged you.

That's what I thought, it says 1 qt. so I'm gonna assume they didn't do the transfer case.

 

[madar]

They're not going to charge you for .7 qts. Fluid comes in 1 qt. bottles, they'll charge for the whole bottle.

 

[cz5gt]

so 1 qrt on invoice => only one is changed.
2 qrts => front and rear changed.
I would ask do the transfer too if it was me.
With dealers I found that one has to ask specifically and double confirm everything.
Otherwise its always hit and miss depending on the dealer.

 

[Yo'sDad]

I'm sure I'll get hit with "you don't need to do that", haha, but I'm one of 'those' people, go ahead, I can take it. Today at 5K I changed my transfer case and differential lube, and transmission fluid and filter. The lube may have not needed changing, but I was amazed at how little fluid drained out of the differential. I did not measure what came out of the xfer case but it was dark and lots of light colored swirls and as expected the drain magnet had a good amount of metal, same for the differential but only 10 oz came out. So at the very least I know that both are full to the inlet plug. For those considering this, be aware that the drain plug is a 24mm and the fill plug is a 23mm. Why????? BTW it is a 23 NA Carbon.

 

[yrwei52]

I'm sure I'll get hit with "you don't need to do that", haha, but I'm one of 'those' people, go ahead, I can take it. Today at 5K I changed my transfer case and differential lube, and transmission fluid and filter.

Yes, "you don't need to do that" at only 5K miles. But it’s your CX-5. Nothing would be hurt by changing those fluids early but your pocket.

The lube may have not needed changing, but I was amazed at how little fluid drained out of the differential. I did not measure what came out of the xfer case but it was dark and lots of light colored swirls and as expected the drain magnet had a good amount of metal, same for the differential but only 10 oz came out. So at the very least I know that both are full to the inlet plug.

Yeah the spec from Mazda says it’s 0.37 quart for rear differential on your 2023 CX-5, but you actually need 0.7 ~ 0.8 quart to fill the rear differential to the brim of the fill hole as instructed by Mazda workshop manual.

For those considering this, be aware that the drain plug is a 24mm and the fill plug is a 23mm. Why????? BTW it is a 23 NA Carbon.

And the size of the aluminum washer used on these 2 plugs are the same. This’s another example of Mazda way trying to be different from everybody else?

 

[weitau]

Yes, on the CX-5 and all current Mazda i-Activ AWD system.

The only exception on Mazda vehicles is the gen-1 CX-9 (2008 ~ 2015) and frequent FTC oil change is necessary.

Yrwei52, does this mean I don't need to service my diff or FTC? I have a 2014 CX5 AWD with 158k miles.

 

[yrwei52]

Yrwei52, does this mean I don't need to service my diff or FTC? I have a 2014 CX5 AWD with 158k miles.

You definitely want to change the gear lube in both front transfer case and rear differential at 158K miles.

CX-5 Rear Diff and Transfer Case Fluid Change: Tools, Parts and Links

A couple of notes: you need about 0.7 quarts of gear lube for real differential instead of 0.48 quarts stated in the manual. You need 0.48 quart gear lube in front transfer case as stated in the manual. Secondly, the factory fill in rear differential is pretty low as reported by many here.

The debate to me is what type of gear lube should I use on the 2014 CX-5? Mazda has changed the gear oil spec to Mazda Long Life Hypoid Gear Oil SG1 from traditional 80W-90 GL-5 since 2016 MY. SG1 is pretty expensive and you need to get 2 bottles for the change on both.

 

[ctbale]

Yes, "you don't need to do that" at only 5K miles. But it’s your CX-5. Nothing would be hurt by changing those fluids early but your pocket.



Yeah the spec from Mazda says it’s 0.37 quart for rear differential on your 2023 CX-5, but you actually need 0.7 ~ 0.8 quart to fill the rear differential to the brim of the fill hole as instructed by Mazda workshop manual.



And the size of the aluminum washer used on these 2 plugs are the same. This’s another example of Mazda way trying to be different from everybody else?

Ok, your post was almost 2 months ago and nobody was confused? You say Mazda says .37 for the correct quantity of oil? But if you keep pumping it takes .7 ish to get to the fill hole? So should people measure and add .37?

Many many Chevy rear diffs are funny like that and nobody knows it or cares. The book says 5/8" to 1-5/8" below the hole. I use an Allen key with a 3/4" short leg. It's a perfect 2 qts. But if you fill to the hole it's 2.5 qts. ( maybe 2.8, can't remember ) AND your pinion seal will start to seep/leak sure as s*** because it's not meant to hold back oil 24/7. Only splash.

 

[ctbale]

Just missed your last post. So short question. Maybe Mazda doesn't want it to the fill hole?

 

[yrwei52]

Just missed your last post. So short question. Maybe Mazda doesn't want it to the fill hole?

These are from Mazda Workshop Manual:

So if you follow the instruction, refill the front transfer case to the brim of the fill hole you will need stated 0.48 quart. But refill the rear differential to the brim of fill hole you will need 0.7+quart, NOT the stated 0.48 quart.

It’s like engine oil capacity, 4.8 quarts in specs, but needs 5.2 quarts on 2.5L NA; 5.1 quarts in specs but needs 5.5 quarts on 2.5T. Mazda stated in the manual that those fluid capacities are “approximate”. But they’re really inconsistent with wide range!

BTW, one member with a newer 2021 CX-5 turbo AWD reported he used 0.5L (0.528 quart) when he refill the rear differential. But for Gen-2 CX-5 the spec is 0.37 quart, not 0.48 quart for rear differential.

 

[ctbale]

Yup. My 2.5t takes a perfect 5.5 w/filter if I go by the stick.

And thanks for posting the info. With that info I would go to the hole and disregard the .48 qt instructions. But there is clearly an error on the diff data. Either .48 is correct or the fill hole is correct. Another poster says the fill hole is above the axle seal which is similar to the Chevy situation. I wonder if there has been a revision to the manual. Leaving the factory now to the fill hole would make me think yes.

 

[yrwei52]

⋯ Many many Chevy rear diffs are funny like that and nobody knows it or cares. The book says 5/8" to 1-5/8" below the hole. I use an Allen key with a 3/4" short leg. It's a perfect 2 qts. But if you fill to the hole it's 2.5 qts. ( maybe 2.8, can't remember ) AND your pinion seal will start to seep/leak sure as s*** because it's not meant to hold back oil 24/7. Only splash.

For those who have been doing lube changes on this type of fluid change application, manual gear box、differential、transfer case、etc., we always fill the gear lube to the brim of the fill hole for easy level measurement. If that isn’t the intended fluid level, the manufacture should relocate the fill hole for proper fluid level. Mazda didn’t do it for it’s rear differential if the stated capacity is correct; and Chevy didn’t do it either.

Luckily there’s no leaks been reported when people refill the gear lube to the brim of the fill hole of the rear differential with 0.7 quart.

 

[ctbale]

Yea, on the Chevy there is a stiffner web where the hole should go. And if they put it below that web it would be too low. Also that diff is rotated in different trucks so Chevy put the hole high and addresses the quantity via the shop manual.....which nobody reads.

 

[ctbale]

Hmmm. The more I scratch my head on this, the .48 might be correct. Gunna have to go take a peak at my diff and see what's going on with the casting below the Mazda diff fill hole. Like you said, if they wanted .48, lower the dam hole.