Subaru or Mazda?

[ARCOgraphite]

Have you actually owned a Subaru? I can tell you that over 18+ years of owning or maintaining 9 different Subarus for well over 1M cumulative miles, there has not been a single differential failure or even issue with diffs, and that not only were all 4 tires not maintained “identically”, many of them went 15-20k between tire position rotations.

We had our previous Crosstrek about to lunch a wailing rear diff, but I caught it in the nick of time - appears the Subaru dealer used some garbage bulk Mobilube HD 85w90 at the 30k mile requested D&F.

Had a similar issue in a prior year on my Nissan Rogue select. I Drain and refilled with some WM Supertech semisyn 75W90 in a bladder bag. and all was well in a few hundred miles. Surprisingly. Why I pay to have the service center do simple stuff IDK. Maddening.

Our current diff on the '23 Crosstrek appears to have no fill plug port! What's up with that?

- Arco

 

[CarbonToast]

Both the latest Forester/Outback and CX-5/50 use a transaxle with a coupler. Their AWD systems are not that different in terms of power distribution, unless you mean left to right, in which case the Subaru does use equal-length axles. There is no way for Subaru to send more than 50% of the engine power to the rear axle unless they use a center differential, which their CVT systems sans-WRX do not utilize.

This isn't true. The current forester uses the TR580 which has been in production for ~10 years. The transmission case also houses the front diff but it does not share fluid. There is a rear output for the driveshaft to the rear diff.

The Mazda a transverse setup like a front wheel drive car. The subaru is longitudinal like a rear wheel drive car.

 

[ARCOgraphite]

I like the feel of a longitudinal drivetrain layout jacking the DS front wheel when you hammer the gas.

It feels like ... Victory!

 

[pbm]

So wadja get?

She ended up buying neither. She went to the dealer and got a good deal on a used 2022 Hyundai Kona 2.0 N/A with 28k miles. It appears to be a higher end model with sunroof, nice wheels, AWD, faux leather seats etc…I would have avoided H/K products right now due to their engine self destruction tendencies but I’m hoping for her sake they were solved by 2022. I see that the 2022 Kona has a CVT so I’ll try to encourage a fluid change. Do these require Hyundai brand CVT fluid or would Valvoline, Castro etc….suffice?

PS: I realize the Kona is smaller than either the Forester or CX-5 but she picked it so she must have found it big enough…

 

[Glenda W.]

We had our previous Crosstrek about to lunch a wailing rear diff, but I caught it in the nick of time - appears the Subaru dealer used some garbage bulk Mobilube HD 85w90 at the 30k mile requested D&F.

Had a similar issue in a prior year on my Nissan Rogue select. I Drain and refilled with some WM Supertech semisyn 75W90 in a bladder bag. and all was well in a few hundred miles. Surprisingly. Why I pay to have the service center do simple stuff IDK. Maddening.

Our current diff on the '23 Crosstrek appears to have no fill plug port! What's up with that?

- Arco

I just did my diffs. Front fill port is on the passenger side right next to where the cv joint goes into diff. Rear Im sure you see on the cover above drain plug.

 

[Glenda W.]

Have you actually owned a Subaru? I can tell you that over 18+ years of owning or maintaining 9 different Subarus for well over 1M cumulative miles, there has not been a single differential failure or even issue with diffs, and that not only were all 4 tires not maintained “identically”, many of them went 15-20k between tire position rotations.

Same here. Have had at least one Subaru in the fleet since the late 70’s. Never a diff failure. Have had differently worn tires many times. It’s simply not that sensitive.

 

[Jarpin]

I would go Mazda, as it is not a cvt.
I won't buy a car with a cvt, but that's just me.

Forget the CVT for a minute. I'm more concerned about GDI carbon buildup in both of these newer engines. I was leaning towards the Mazda CX-5 over a Subaru, but then I decided to go with a Mitsubishi OS because it still employs port fuel injection. True it's a little more sluggish and handles poorly, but I'm thinking that older tech will prove more dependable over 100k. Also their Jatco CVT's are not failure prone if cared for, unlike their other corporate shareholders' automotive junk piles.

 

[duck__dodgers]

Forget the CVT for a minute. I'm more concerned about GDI carbon buildup in both of these newer engines. I was

Skyactiv GDI has been out long enough that if carbon buildup is an issue, the Mazda forums would be moaning about it by now.

dunno about Sub.

 

[IveBeenRued]

She ended up buying neither. She went to the dealer and got a good deal on a used 2022 Hyundai Kona 2.0 N/A with 28k miles. It appears to be a higher end model with sunroof, nice wheels, AWD, faux leather seats etc…I would have avoided H/K products right now due to their engine self destruction tendencies but I’m hoping for her sake they were solved by 2022. I see that the 2022 Kona has a CVT so I’ll try to encourage a fluid change. Do these require Hyundai brand CVT fluid or would Valvoline, Castro etc….suffice?

PS: I realize the Kona is smaller than either the Forester or CX-5 but she picked it so she must have found it big enough…

Thanks for closing the loop. I wish her luck with the Kona. I’ve rented a few; nice little cars and surprisingly good radios. I too hope they solved the whole self destructive engine thing.

 

[redbone3]

Have you actually owned a Subaru? I can tell you that over 18+ years of owning or maintaining 9 different Subarus for well over 1M cumulative miles, there has not been a single differential failure or even issue with diffs, and that not only were all 4 tires not maintained “identically”, many of them went 15-20k between tire position rotations.

I define a bad differential as a differential that cannot perform it's primary duty: compensate for the wheels turning at a different rate.

 

[jakeuten]

This isn't true. The current forester uses the TR580 which has been in production for ~10 years. The transmission case also houses the front diff but it does not share fluid. There is a rear output for the driveshaft to the rear diff.

The Mazda a transverse setup like a front wheel drive car. The subaru is longitudinal like a rear wheel drive car.

The TR580 is mounted longitudinally, but it is a transaxle because power flows to the front wheels first. Their CVT cars do not have a center diff to power the rear wheels beyond 50% on dry pavement. They use a coupler like every other FWD-AWD car. It does seem to be far more robust than a lot of the other “hang-on” systems though, according to the videos I’ve seen from Driving Sports TV. That’s different from their manual transmission cars because power is split at the center differential, same with the CVT WRX. I was quite a fan of the 5EAT VTD system in the older Outbacks as well.

 

[Exhaustgases]

Easy choice, Mazda, they don't do CVT's.

 

[SubieRubyRoo]

I define a bad differential as a differential that cannot perform it's primary duty: compensate for the wheels turning at a different rate.

And you have actual examples of Subarus failing to do their primary duty?

 

[redbone3]

And you have actual examples of Subarus failing to do their primary duty?

If they could do that, there would be no requirement for near identical tires.

 

[Jimmy_Russells]

If they could do that, there would be no requirement for near identical tires.

this isn't something unique to Subaru

 

[redbone3]

Nevertheless, I call it bad engineering, no matter what manufacturer.

 

[SubieRubyRoo]

Nevertheless, I call it bad engineering, no matter what manufacturer.

Bad engineering how? Something written in a manual ages ago, as a precaution/recommendation (which was likely just to boost tire sales at the dealer), with no supporting failed differentials in decades since is hardly bad engineering.

Certainly there have been millions of combinations of the things Subaru warned against and yet there’s no evidence anywhere that this has caused failures, makes your position more ludicrous than the LSPI boogeyman. Lots of hype, not much objective evidence it’s as destructive as claimed.

And yes, I’ll use other, lesser AWD vehicles as examples that the caution only truly applies if you have different size ODs (26” vs 28” ex.); tire size that started with same overall height, worn from driving or misalignment are never going to damage the differential systems.

 

[Pew]

I define a bad differential as a differential that cannot perform it's primary duty: compensate for the wheels turning at a different rate.

But it does exactly that, compensate by locking the diffs. Too long of a lock and it burns up, especially when only partially locked.

 

[ARCOgraphite]

I just did my diffs. Front fill port is on the passenger side right next to where the cv joint goes into diff. Rear Im sure you see on the cover above drain plug.

Nope, it is gone with the new cover design. I have a photo with the car on the lift in the hot rod shop but it was a low-res phone photo.

Might be able to do and extraction for a partial drain and fill. I am not inclined to remove the cover to drain it. magnetic plug to the rescue. Frustrating. Thanks Subaru.

What year is your vehicle? 2018 outback? That may be a diff diff. Up front, my wife has a 6 speed MT which I think is a shared lube sump, so that special juice will stay till 60K. Just waiting for balky shifts when they use the incorrect lube. Death by bulk gear oil.

 

[Glenda W.]

Nope, it is gone with the new cover design. I have a photo with the car on the lift in the hot rod shop but it was a low-res phone photo.

Might be able to do and extraction for a partial drain and fill. I am not inclined to remove the cover to drain it. magnetic plug to the rescue. Frustrating. Thanks Subaru.

What year is your vehicle? 2018 outback? That may be a diff diff. Up front, my wife has a 6 speed MT which I think is a shared lube sump, so that special juice will stay till 60K. Just waiting for balky shifts when they use the incorrect lube. Death by bulk gear oil.

View attachment 250540 View attachment 250542

Good to know. Thanks! Mine is an 18 Outback. My friend just bought a 24 Crosstrek so I’ll need to service it eventually.