2016 CX5 Transfer Case + differential oil change

[GoodGuyDudu]

Hey folks,
I have a few questions regarding this. Did not see anything about this model anywhere.
First, I read that I may have to fill the transfer case and rear diff with more oil then what is actually specified in the manual, is that correct? Is there such thing as actually overfilling the TC and rear diff, or filling them at the really top is okay? Also, are all the four washer the same part from Mazda ? (2 from transfer case and 2 for rear diff). Lastly, should the car be on a flat surface or ramps work?
Thank you!!

 

[yrwei52]

Here’s a great thread which has all answers you want:

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

Just make sure when you follow the procedure, you need 0.75 ~ 0.85 quart gear lubricant for rear differential than stated 0.48 quart (0.37 quart for gen-2 CX-5). The front transfer case needs 0.48 quarts as stated. You won’t over-fill the gear lubricant as the full level is at the brim of the fill hole. Make sure to use Mazda OEM Long Life Hypoid Gear Oil SG1 and you need to get 2 bottles for the job. 4 washers are all 18 mm. Finally, make sure to lose the fill hole first then drain the gear oil.

 

[GoodGuyDudu]

Here’s a great thread which has all answers you want:

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

Just make sure when you follow the procedure, you need 0.75 ~ 0.85 quart gear lubricant for rear differential than stated 0.48 quart (0.37 quart for gen-2 CX-5). The front transfer case needs 0.48 quarts as stated. You won’t over-fill the gear lubricant as the full level is at the brim of the fill hole. Make sure to use Mazda OEM Long Life Hypoid Gear Oil SG1 and you need to get 2 bottles for the job. 4 washers are all 18 mm. Finally, make sure to lose the fill hole first then drain the gear oil.
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View attachment 226785

Damn! You know your stuff! Thank you for your help! I see we have the same model, pretty cool. Maybe just one more question for you. So the oil needed for transfer case will bring it to the filler plug level (can't take anymore oil), but for the rear diff you have to use the specified amount and not just vring it to MAX capacity, right?

Thanks again for your help and time, greatly appreciated!

 

[yrwei52]

Damn! You know your stuff! Thank you for your help! I see we have the same model, pretty cool. Maybe just one more question for you. So the oil needed for transfer case will bring it to the filler plug level (can't take anymore oil), but for the rear diff you have to use the specified amount and not just vring it to MAX capacity, right?

Thanks again for your help and time, greatly appreciated!

No, for rear differential you “add the specified differential oil from the filler plug until the level reaches the brim of the plug hole.” See step 5 in the second picture from Mazda Factory Workshop Manual posted above. By doing this, you’d need 0.75 ~ 0.85 quart of gear oil.

This’s a common practice to add the oil to the bottom of the fill hole in such application like front transfer case、rear diffrtential、and manual transmission.

The fluid capacities stated in Mazda’s manuals are approximate and sometimes is widely off like the rear differential gear oil which is 66% off! The engine oil said to be 4.8 quarts for oil change on 2.5L, but you need 5.3 quarts in real life to make the oil level to reach to the FULL mark of the dipstick. On the other hand, front transfer case needs exactly 4.8 quarts like stated. This’s something caught me and many others by surprise at the first place as the CX-5 is my first Mazda. The other thing I need to get used to is the Mazda Factory Workshop Manual is always giving a range of the torque value, while others are giving a single torque value. Of course YMMV.

 

[GoodGuyDudu]

No, for rear differential you “add the specified differential oil from the filler plug until the level reaches the brim of the plug hole.” See step 5 in the second picture from Mazda Factory Workshop Manual posted above. By doing this, you’d need 0.75 ~ 0.85 quart of gear oil.

This’s a common practice to add the oil to the bottom of the fill hole in such application like front transfer case、rear diffrtential、and manual transmission.

The fluid capacities stated in Mazda’s manuals are approximate and sometimes is widely off like the rear differential gear oil which is 66% off! The engine oil said to be 4.8 quarts for oil change on 2.5L, but you need 5.3 quarts in real life to make the oil level to reach to the FULL mark of the dipstick. On the other hand, front transfer case needs exactly 4.8 quarts like stated. This’s something caught me and many others by surprise at the first place as the CX-5 is my first Mazda. The other thing I need to get used to is the Mazda Factory Workshop Manual is always giving a range of the torque value, while others are giving a single torque value. Of course YMMV.

That is really good to know! Thank you so much! I'm quite new to that AWD system, had FWD cars before. So If I got you correctly, I would fill both the transfer case and rear diff until I reach the brim of the plug hole. That is quite an easy DIY maintenance then! Was afraid to do it myself, but looks quite simple, and you reassured me with good info. Thanks for you time again!

 

[yrwei52]

That is really good to know! Thank you so much! I'm quite new to that AWD system, had FWD cars before. So If I got you correctly, I would fill both the transfer case and rear diff until I reach the brim of the plug hole. That is quite an easy DIY maintenance then! Was afraid to do it myself, but looks quite simple, and you reassured me with good info. Thanks for you time again!

Make sure to read the entire thread I posted earlier.