Rear Diff and Transfer Case Fluid Change: tools parts and links

[Kedis82ZE8]

I changed mine after vehicle sat in the garage overnight.

[Lbear]

I changed the front and rear differentials AWD (6,500 miles)

The rear differential was tightened by some gorilla because it was tough to break the plugs. Finally did it and drained it. There was about 1/4 inch of metal shavings on the magnet and the fluid was nasty. When clutch plates break-in, they release tons of debris before they get their mating and wear in pattern. I'm glad I changed the fluid.

The front differential was a lot easier to remove the plugs BUT the drain plug didn't tighten down with the torque wrench properly and left me uneasy. I think they over tightened it at the factory or the threads were not properly cut at the factory. So I put down about 2 wraps of TEFLON TAPE on the bottom drain plug. I hand tightened it with a 3/8" drive until it felt tight and took it for a spin. No drips, no leaks. The front differential drain plug faces straight down.

The rear plugs were torqued to 30ftlbs and the fronts were tightened with a 3/8" drive to snug.

Here if the fluid at 6,500 miles:



This is what the new fluid looks like:

[Kedis82ZE8]

i feel lot better about having changed mine too. I plan to change AT fluid before 30K miles... still need to order that fluid and find a weekend with some time.

EDIT: I am glad this entire driveline is fairly easy to maintain. I cringe at what the '07-'15 AWD CX-9 owners have to go through to maintain the "lifetime" fluid in their transfer case.

[Lbear]

i feel lot better about having changed mine too. I plan to change AT fluid before 30K miles... still need to order that fluid and find a weekend with some time.

EDIT: I am glad this entire driveline is fairly easy to maintain. I cringe at what the '07-'15 AWD CX-9 owners have to go through to maintain the "lifetime" fluid in their transfer case.

I might do the transmission a little earlier than that. Maybe around 15k miles. There is usually a lot of break-in clutch material on new transmissions, just like differentials.

[yrwei52]

Genuine Mazda Fluid (0000-77-80W9-QT) SAE 80W-90 Rear Differential Oil - 1 Quart
http://www.amazon.com/Genuine-Mazda-...s=mazda+80w-90

According to owner's manual, both front transfer case and rear differential use Mazda Long Life Hypoid Gear Oil SG1, part no. 0000-77-SG1-QT, with list price $29.95 per quart:


OP used different Mazda gear lubricant, Mazda Premium Rear Axle Lubricant SAE 80W-90, part no. 0000-77-80W9-QT, with much lower price:


I think I'd use Mazda Long Life Hypoid Gear Oil SG1 when the time comes.

[CX5-SO]

As stated in manuals.

[yrwei52]

As stated in manuals.

Thanks for the clarification. So Mazda changed recommended gear lubricant for its AWD system although the system is the same through all model years. Since Mazda Long Life Hypoid Gear Oil SG1 recommended now is almost 3 times more expensive than Mazda Premium Rear Axle Lubricant SAE 80W-90, I'd say something must be added to it for better performance or longivaty to Mazda's AWD system. It only takes a quart for the change, I'd definitely go with new and more expensive Mazda Long Life Hypoid Gear Oil SG1. Wonder what gear lub did Lbear use for his 2016 CX-5?

OP, it'd be nice to add this spec change image in your original post to prevent the confusion on gear lubricant, as many members here will use your post for reference ordering tools and parts like I did. And again thanks for the very helpful info!

[Kedis82ZE8]

I used Amsoil in mine. No concern about lubricating qualities. Perhaps I will lose some .x on the MPG but not gonna sweat it. I've said this before but on rear diff... rear fluid was not at fill line on stock fill. I put in more fluid than what came out. A few others who changed said the same. FSM states to fill line for proper level.

EDIT: I plan to change every 20-25K miles so long life fluid does not really blend in with my maintenance schedule. Transfer case oil quantity was seemingly spot on though.

[yrwei52]

I used Amsoil in mine. No concern about lubricating qualities. Perhaps I will lose some .x on the MPG but not gonna sweat it. I've said this before but on rear diff... rear fluid was not at fill line on stock fill. I put in more fluid than what came out. A few others who changed said the same. FSM states to fill line for proper level.

EDIT: I plan to change every 20-25K miles so long life fluid does not really blend in with my maintenance schedule. Transfer case oil quantity was seemingly spot on though.

For your 2015 CX-5 AWD, does the owner's manual specify gear lubricant for transfer case and rear differential the same as 2013's or 2016's? And are you saying the rear differential needs more than factory specified 0.48 US quarts to fill up to the filler hole? So one quart of gear lubricant may not be enough for the lub change for both?

CX5-SO, thanks for adding the specs!

[Kedis82ZE8]

Mine is same as 2013. Correct. I needed more than one quart to change both. Front was seemingly spot on... rear needed more than half quart. Unfortunately I didn't measure. I don't think 3/4 quart but it seemed around or shy of 2/3 quart was what it took.

EDIT: Vehicle was cold and level.

[yrwei52]

Mine is same as 2013. Correct. I needed more than one quart to change both. Front was seemingly spot on... rear needed more than half quart. Unfortunately I didn't measure. I don't think 3/4 quart but it seemed around or shy of 2/3 quart was what it took.
EDIT: Vehicle was cold and level.

Very appreciated for your info! Otherwise for $30 a quart, I'd just get a bottle of Mazda Long Life Hypoid Gear Oil SG1 thinking it should be enough for 0.48 US quarts X 2 but ended up I've to get more during the change! Not good!

[Tom 6-6]

Any idea how much dealers charge for this service?

[Chris_Top_Her]

I think I paid 80 with materials the first time I ever had it done

[runtohell121]

When changing the differential fluid... Do you just add/pump in the fluid until it leaks? Or is there a way to measure how much fluid should be added into the differential? Planning to do the differential fluid change soon.

[Conrad 16.5]

When changing the differential fluid... Do you just add/pump in the fluid until it leaks? Or is there a way to measure how much fluid should be added into the differential? Planning to do the differential fluid change soon.

Just fill it till the oil starts dribbling out of the fill hole. Allow it to drip till it stops then put the filler plug in and away you go.


FYI, Mazdastuff.com has the SG1 for $21.56