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2002 outback rear differential

I have a 2002 outback standard with 50,000

miles. The dealer says it has a broken rear differential and needs a new transmission.



Fluids have been maintained. This may be bad lucj but does not sound right to me. Thanks

None of us can tell from here. Get a second opinion, preferably from an independent Subaru specialist shop, if there is one near you. Did the dealer elaborate on how this might have happened in so few miles?

What symptoms present themselves to you as you drive the car?? Subaru’s have more than their share of mechanical problems, but that rear differential unit is pretty trouble free unless, somehow, they get water in them…

If it turns out you DO need new gear-boxes, a salvage yard is the place to find them, not the dealers parts department…

Were the tires mismatched (eg one replaced instead of 4) over its lifetime?

I think you may be off in your reporting of issue. The drivetrain of Subaru consists of front differential, viscous coupling(center diff), rear differential, axles/shafts, and the manual transmission itself.

The two items you list do not sound right failing either.

I will add the manual transmission Subaru AWD drivetrain is near bullet proof in durability and reliability.

Many thanks–this is what I was thinking, although the independent shop has not replaced a Subaru transmission. The dealer was very careful not to answer any questions about how this could have happened. You confirmed what I was thinking at the moment, so thanks again. their quote on a used transmission with 150,000 was 2,800 and a new one was 6,000–they do not “fix” transmission, just replace them.

It does not sound right to me eiether–I am just reporting what dealer told me–I need a new transmission and specific “broken” part is rear differential.

Symptoms were a burning smell–electrical or rubber, which was trandsmission fluid leaking from a broken seal.

Tires were matched and maintained. Sorry if this does not add up it dos not add up to me either.

The transmission and the rear differential are two separate things. Either one being broken would not affect the other, and neither should be bad at only 50K miles.

Thanks again for your reply, does this eman “broken” differential does not equal broken transmission. Independent shop saysthe smae thing, but I am not in a city.

It seems to me there is a lot of story missing here. While both units failing at 50k miles is highly unusual it would not be unusual if there was a human underlying factor.
Some more info might help.

Automatic or manual transmission?
You state the fluids have been maintained. Are you checking these yourself?
Any symptoms involving a subtle whining sound before this happened?
Who services this car as to oil changes, etc.?

I can give you a decent theory behind this but more info would help. It may not sound right to the person who has to pony up on this but it very well could be right depending on the background.

This is a manual. Fluids and so on have been regularly serviced at dealer. No whining sound.

Unfortunately this manual is my wife’s car and she might not be the best person to drive a manual (new clutch needed at 30K)–would this trash a transmission?

It is good of you to answer–human factor may be riding the clutch or who knows, but wouldn’t this burn out clutch–what I do not get is why both independent shop and dealer treat rear differential as just part of transmission which has to be replaced etc.

Is the car drivable?? Ask a shop to put the car up on a lift and allow YOU to inspect the gearboxes. The rear end is quite simple. It either turns smoothly and freely or it doesn’t. It may be necessary to disconnect the rear driveshaft to isolate the two gearboxes and see which one has the problem…

Getting only 30k miles out of a clutch is most often a sign of hard driving or riding the clutch pedal but I’m inclined to think the transmission/diff problem is not related to that. Here’s my theory based on the leak and the burning smell.
Odds are the leak was due to an axle shaft seal which drips onto the exhaust.

  1. If the trans oil gets catastrophically low the trans will develop a whine over time and the driver becomes accustomed to it until it makes a bang and that’s it. The transmission seizes up due to a trashed ring/pinion gear. (auto or manual, either one)

  2. If the trans oil gets very low (not as above) the transmission can seize up but for a different reason. The capacity is about 7 pints and if it’s 2 or 3 pints down inadequate oil may be provided to the bearings on the mainshaft and the mainshaft rear bearing will usually seize up. (the mainshaft bearings ride in the upper area of the transmission case; manual only)

If the transmission locked up or was attempting to lock up over a number of miles I would say that it’s possible the added strain could ruin the differntial.

Without seeing the damage about all I can provide is a plausbile theory and I hope it helps some.
I am still curious about some of the symptoms though. Was the vehicle driving fine, no noises, etc. other than the smell? Was the car driven in or towed?

Thanks for replies and sorry for bad info–it was front differntial. The fluid was kept at proper levels (I am very careful about this) and the broken front differential was just a bad part.

So Subaru makes a bad part once in a while and a few people get unlucky or the longevity is hype people want to beleive because cars like Volvos are now unreliable luxury cars. I would not buy another just because of the way the company has acted. I do not see any transmission going at 50K or any excuses for this company and its dealers who live in the stone age of customer service.

No noise other than smell.

I do appreciate theory re: oil but records indicate

My theory pretty much aligns with ok4450’s theories.
I think that this car has–despite the OP’s claims–not been maintained as well as it should have been. Bad maintenance can spell an early demise for many automotive components.

This low mileage car should have been maintained according to the Severe Service Maintenance Schedule, meaning that the differential oil and the transmission oil should have been changed twice already, with a 3rd change coming up very soon. Were they serviced in this manner?

I appreciate your diiligence in car maintance and will certainly check records at service center as I hand over 5-6K for a transmission at 50K. It is certainly possible the car was not maintained at levels suggested in last post. Is this a forum for mechanics who are highly knowledgable and so can see where others went wrong and feel certain brands do not have defects?

The tone here suggests to me the practice of company PR making sure no criticism of products hits the web. The ethcical way to do this is to identify yourself as representing the company. If it is just people who know a lot about cars and have caught some owner lapse in changing trans fluids on time my apologies. Maybe I am being told fluids were changed when they were not. This means everyone driving a Suburu with over 50K maintains it as post above suggests and has diligent honest dealer maintance (give me a break), or, site is being monitored. This is pretty sad on an NPR site, but common practice.

At least, if you are all right, someone will read this and change their transmission fluid more often. The dealer more or less admitted to a faulty part and said fluids had been changed on schedule, but I guess Suburu cannot make a bad part according to above. There is no good independent shop here which I imagine is next reply.

I disagree with your view on servcing or lack of had anything to do with this failure. The service schedule calls for an inspection of fluids not replacement. Also standard transmissions simply do not fail from old fluid. Some standards go 200k+ with the original fluid.

Let me add something else here. You refer to a trans leak and the main suspect here would be an axle shaft seal.
Axle shaft seal leaks are near unheard with the exception of very high mileage and/or aged cars. Even then, it’s not that common.

You also refer to having a clutch installed so another more likely scenario would be that whoever did the clutch job got a bit ham-fisted when removing and installing the halfshafts during the clutch job and damaged the seal inadvertently.

The damaged seal then leaked out the gear oil which in turn trashed the transmission and differential. (diff. being inside the transmission case of course)
Subaru manual transmissions hold up very well and this failure sounds more like human error rather than a bad transmission assembly.

I am not employed by any car company, and am merely a car owner who is very diligent about car maintenance. As a result of that diligence, I have never had a major mechanical breakdown on any car that I have ever owned–even with odometer mileage of well over 150k miles.

When fluid “inspections” are called for at 30k, 60k, 90k, etc, I have fluids changed rather than merely inspected. Yes, it costs me a few more bucks at the time of each service, but the total cost of all of this maintenance is far lower than what it would cost to replace transmissons, differentials, etc.

And, of course, it is far more convenient for me to schedule this maintenance when it is convenient for me, as compared to unscheduled, unpredictable mechanical breakdowns. I guess that is why whenever I am ready to get rid of one of my cars, there is a waiting list of co-workers who want to buy my car. After I am finished with a car, it typically runs without incident for the next owner for many years, assuming that he also maintains the car well.