FWD & AWD Differntial Gear Oil

[Bruns]

FWD & AWD Differntial Gear Oil

1.5 only...
It's actually plenty for the 40km/h speed limits in Japan.
Even for major highways the speed limit is 80-100 km/h

*next year they will also sell a 1.5 Turbo Diesel with the awd option.

It really sucks that we get no engine choice. But that's life


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[Anchorman]

Which would be stronger or better, having a front differential that is housed in an aluminum case with differential fluid OR being housed inside of a transmission case?

Sorry buddy, I took you seriously at first but I'm beginning to think you are just guessing at all this. To start with, why do you think that not changing the diff oil early will cost thousands? The oil from the rear diff is absolutely normal and is only grubby because of the normal clutch wear in the drive unit. Mazda know it does that and they recommend oil changes that take it into account. Additionally, you have not shown the oil from the front diff because it doesn't look nearly as bad. Why try to sensationalise it?

After reading your guesses at what is going on in the transmission, I initially thought I was failing to understand what you meant but now I see you have no idea about transmissions generally never mind in relation to the CX-5. Forget about hypothetical comparisons, the transmission is more than capable. Sorry but I don't see the point of what you are doing.

For information, the gearbox, manual or automatic and the diff are identical in both FWD and AWD. The only time it starts to get different is with AWD models where they bolt a transfer box on the casing as means to drive the rear axle. Where this notion that they are a different drive arrangement comes from I cannot imagine. I do have the complete CX-5 manual if anyone wants to see PDFs.

 

[CX5_Pete]

Which would be stronger or better, having a front differential that is housed in an aluminum case with differential fluid OR being housed inside of a transmission case?

I don't think just because a differential housed in its own case is indicative of its strength or ability to handle power or if its "better."

For example, lets take some moderately powered AWD cars that utilize a transaxle where the front diff and transmission are housed in the same case: WRX STi and Lancer Evo. These cars have their front diffs and tranny in one case and can handle 300+ HP. The FQ440 Evo had 440 HP. Another example would be a Porsche 911 GT3, except now the engine is in back and again the diff and tranny are housed in the same case. The current 991 GT3 with the 4.0 makes 500 HP and 300 something Ft-lbs.

Not a lot of vehicles that come to mind to me at the moment that have all differentials in its own case except for most 4WD trucks and the legendary Acura Legend (pretty sure there are other examples). Trucks have a separate diff for the front more for packaging and weight distribrution reasons than for it being heavy duty. As for the Acura Legend, well... I remember reading somewhere that Honda claimed it would improve handling or something like that. I think they just wanted to look like the other high end european makes and Lexus.

However it is easier to service a diff with a separate case if you just want to only service the diff like switching out gears, use different oils, add a limited slip, etc.

I do agree with you that a vehicle equipped with AWD or 4WD can put more power to the ground and fully utilize it.

One last thing in regards to the diff fluids for the CX-5. Even though the diff fluid may look murky, it doesn't mean that the oil cannot do its job or is harming the differentials. I worked on a Nissan 240SX with a full Sylvia conversion and it had a LSD in back. The owner liked to change his fluids annually he barely put less than 10K miles a year on that thing. And even with the low mileage he was driving, the fluid still looked dirty everytime I changed it. I think it would be interesting to see what an oil analysis would show for the CX-5 diff fluid at 50K miles.

Having said all this, it's your guys' CX-5, if it makes y'all feel better to change it early, then by all means. And its cheap.

 

[Lbear]

.

The front differential fluid looked IDENTICAL to the rear differential fluid. It might have had a little less metal on the magnet but it was still just as murky colored. I didn't take a picture because it looked identical so it served no point.

To each his own. It's $12 to change the differential fluid.

 

[Anchorman]

The front differential fluid looked IDENTICAL to the rear differential fluid. It might have had a little less metal on the magnet but it was still just as murky colored. I didn't take a picture because it looked identical so it served no point.

To each his own. It's $12 to change the differential fluid.

Well thats different to what you said in post 5.

What I would say to those alarmed by the photo of the oil, don’t worry, it is normal and if you change it early it will do it again. It most certainly will not cost you $2000 if you don’t change it early.

 

[Kedis82ZE8]

Not a lot of vehicles that come to mind to me at the moment that have all differentials in its own case except for most 4WD trucks and the legendary Acura Legend (pretty sure there are other examples). Trucks have a separate diff for the front more for packaging and weight distribrution reasons than for it being heavy duty. As for the Acura Legend, well... I remember reading somewhere that Honda claimed it would improve handling or something like that. I think they just wanted to look like the other high end european makes and Lexus.

Actually the ATTESA system used in the AWD Infiniti's has separate transfer case from transmission with front and rear differentials. I have the ATTESA ET-S system in my G35x (V36 Skyline). It appears to have been around since '90 and is still in use today.

If one doesn't want to change early do note the following from the owner's manual.

"*3 If the vehicle is operated primarily under any of the following conditions, replace the rear differential oil at
every 48,000 km (30,000 miles).
a) Towing a trailer or using a car-top carrier
b) Driving in dusty, sandy or wet conditions
c) Extended periods of idling or low speed operation
d) Repeated short trips of less than 16 km (10 miles)
*4 If this component has been submerged in water, the oil should be replaced."

 

[yrwei52]

"*3 If the vehicle is operated primarily under any of the following conditions, replace the rear differential oil at
every 48,000 km (30,000 miles).
...
c) Extended periods of idling or low speed operation"

This one puzzles me like another member pointed out before.

I agree with what CX5_Pete said: "One last thing in regards to the diff fluids for the CX-5. Even though the diff fluid may look murky, it doesn't mean that the oil cannot do its job or is harming the differentials."

So in summary, the front differential is in transmission/transaxle case and using ATF for lubrication on CX-5 FWD; whereas the front differential is in transfer case and using gear oil for lubrication on CX-5 AWD.

 

[CX5_Pete]

So in summary, the front differential is in transmission/transaxle case and using ATF for lubrication on CX-5 FWD; whereas the front differential is in transfer case and using gear oil for lubrication on CX-5 AWD.

The Front diff in the FWD and AWD CX-5 is in the same case as the tranny and share the same fluids. The transfer case just reroutes the driveline 90* so that power can get transferred to the rear.

 

[yrwei52]

The Front diff in the FWD and AWD CX-5 is in the same case as the tranny and share the same fluids. The transfer case just reroutes the driveline 90* so that power can get transferred to the rear.

OK, thanks! So the difference between FWD and AWD on CX-5 is AWD adds a "pure" transfer case and rear differential. I thought in some AWD's rear drive shaft is coming out from "transaxle" case and "transfer case" actually builds into transaxle case?

 

[CX5_Pete]

OK, thanks! So the difference between FWD and AWD on CX-5 is AWD adds a "pure" transfer case and rear differential. I thought in some AWD's rear drive shaft is coming out from "transaxle" case and "transfer case" actually builds into transaxle case?

Sure, there are a bunch of different configurations. If you guys want to nerd out on AWD systems, check this website: http://www.awdwiki.com/en

Actually the ATTESA system used in the AWD Infiniti's has separate transfer case from transmission with front and rear differentials. I have the ATTESA ET-S system in my G35x (V36 Skyline). It appears to have been around since '90 and is still in use today.

I forgot about the ATTESA system. Really interesting stuff.

 

[piotrek91]

So in summary, the front differential is in transmission/transaxle case and using ATF for lubrication on CX-5 FWD; whereas the front differential is in transfer case and using gear oil for lubrication on CX-5 AWD.

I don't think your summary is correct.

The front differential is in the transaxle, lubricated by ATF in both he FWD and AWD model.

The transfer is simply attached to one of the outputs of the transaxle and it is not a differential.

 

[Lbear]

Is the FWD version a "one wheel peel" or does power get distributed to both front tires?

If the FWD only gets power to one tire, then the AWD version puts down power to both front tires and of course the rear tires.

 

[Lbear]

This one puzzles me like another member pointed out before.

I believe the differential case gets moisture inside of it when idling or driving at low speeds since it cannot burn it off from the heat. Sort of like an engine that idles forever, it gets a lot of moisture in the crankcase oil that cannot be vaporized due to the low heat caused by idling.

I just know from numerous mechanics I talked to and being in the muscle car scene years ago. New differentials put out tons of clutch plate material when they break-in. Once broken in the material released drops tremendously. That's why guys would change the fluid relatively quickly on new differentials.

The drain plug magnet had over 1/4" of metal shavings on it. It cannot hold much more since the magnet isn't that powerful. The fluid was nasty and material floating in it. I don't see the harm in spending $12 and a few hours changing it, especially if you plan on keeping the CX5 after the 50k mile warranty is up.

 

[yrwei52]

I don't think your summary is correct.

The front differential is in the transaxle, lubricated by ATF in both he FWD and AWD model.

The transfer is simply attached to one of the outputs of the transaxle and it is not a differential.

Yeah, CX5_Pete corrected me earlier and I ACK it in post #29. Still, thanks for the correction.

 

[Anchorman]

The risk of low mileage is from condensation when the casting is cold and the gears never get chance to reach temperature.


I dont know of any road car that transmits drive to one wheel. Ive attached some info on the boxes here. yrwei52 is quite right, the diffs are contained within the gearboxes so the auto diff is lubricated by ATF and the manual diff is lubricated by gear oil. The transfer box on the AWDs is a simple bevel drive and is lubricated separately two the gearbox with gear oil. The rear diff and drive coupling share the same gear oil.

 

[Anchorman]

In this post Ive added the instructions for changing the oil in all of the drivetrain so there can be no doubt.

 

[Kedis82ZE8]

On the ATF change document I don't have the oil lines over my dipstick in step #2. Is this for a diesel model? My AT dipstick is wide open for access.

 

[Anchorman]

Its actually for all models but that is where an oil cooler is fitted.

 

[Kedis82ZE8]

As you can see from this pic on mine...nothing over the top of the dipstick on mine. Maybe NA models are different?

 

[Kedis82ZE8]

I found changing mine that factory spec on front fluid was fairly close but FSM quantity on rear diff was around 2/3 quart...far more than FSM to get to the fill line.