Center differential dead ( '02 WRX Wagon )

[Black WRX]

Just got my '02 WRX Wagon (manual shift) from service. My pocket is
lighter for exactly US$1100 (parts+labor) after replacing center
differential (63k miles on car). What I'd really like to hear is other's
experiences with this problem. When asking service guy what might caused
this problem he was constantly asking if I was having diferent tire size
(never) or overheating CD by driving in extreme conditions (what's
extreme in regular day-to-day drive, 80% highway!?). Other than that he
didn't have any clue and didn't find anything unusual. He was a bit
surprised having in mind car mileage. This is most likely to be expected
after 100k miles. Anyway, I felt pissed. My opinion is that CD is a bit
more robust and not that prone to overheat/failure in regular driving
conditions.

Does anybody else have similar experience or any knowledge of similar
problem to share? Originaly, I noticed a problem as
'grinding/pulsating' when having wheel turned to lock position and
slowly moving (usually when coming to or leaving a parking spot).
Problem is definitely resolved now after repair but I'd still like to
know what exactly might cause this.

 

[Carl 1 Lucky Texan]

Just got my '02 WRX Wagon (manual shift) from service. My pocket is
lighter for exactly US$1100 (parts+labor) after replacing center
differential (63k miles on car). What I'd really like to hear is other's
experiences with this problem. When asking service guy what might caused
this problem he was constantly asking if I was having diferent tire size
(never) or overheating CD by driving in extreme conditions (what's
extreme in regular day-to-day drive, 80% highway!?). Other than that he
didn't have any clue and didn't find anything unusual. He was a bit
surprised having in mind car mileage. This is most likely to be expected
after 100k miles. Anyway, I felt pissed. My opinion is that CD is a bit
more robust and not that prone to overheat/failure in regular driving
conditions.

Does anybody else have similar experience or any knowledge of similar
problem to share? Originaly, I noticed a problem as
'grinding/pulsating' when having wheel turned to lock position and
slowly moving (usually when coming to or leaving a parking spot).
Problem is definitely resolved now after repair but I'd still like to
know what exactly might cause this.

I think I've read of one other distinctly early CD failure on a manual.
probably just bad luck. The mechanic was asking the right questions.
Other than that...?

Carl

 

[MN]

What about prolonged high speed driving?

Just a hypothesis.

I frequently make long distance trips where I drive very
fast for many many hours at a time. I always worry about
high speeds heating up the relatively small Impreza differentials.
I use synthetic gear lube because of this.

Have you (or previous owner if this applies) done any extensive,
summer-time high speed driving? What about dirty or
old/never changed differential fluid? Or worse, low fluid levels?
This one can surely kill a differential long before 100k miles.

MN

 

[bigjim]

Shouldve bought the extended warranty!!!!!

 

[Black WRX]

Shouldve bought the extended warranty!!!!!

Agree...but every general is smart after the battle is over....

 

[Black WRX]

What about prolonged high speed driving?

Just a hypothesis.

I frequently make long distance trips where I drive very
fast for many many hours at a time. I always worry about
high speeds heating up the relatively small Impreza differentials.
I use synthetic gear lube because of this.

Have you (or previous owner if this applies) done any extensive,
summer-time high speed driving? What about dirty or
old/never changed differential fluid? Or worse, low fluid levels?
This one can surely kill a differential long before 100k miles.

MN

Hmm...on a daily basis I drive approx. 30 miles to work and another 30
back. That's about 2 x 45 minutes of constant drive on highway. Speed is
between 60-80mph and even turbine is idle as I drive in 5th gear at
around 2500-3000 rpm. That should produce minimal load on any car
segment. If differential fluid caused a problem I have to thank service
personell. Since I bought this car back in '01 I didn't miss a single
oil change or any other scheduled service as suggested by manufacturer.
I even keep service history on MySubaru website. Have to check if tranny
fluid was ever changed.

 

[Rob1066]

Center diff replaced on 1999 Forester. $1600 you got off cheap
Mechanic said tired were out of spec, but also have taken several long
distance trips (12-hours driving at a time) that may have contributed
to this. Mechanic also said gasket seal had welded itself to the mount
and that there was rust inside the supposedly sealed unit.

 

[Clamstrippe Fecadunker]

Agree...but every general is smart after the battle is over....

well at least the ones that survive the battle

 

[MN]

Hmm...on a daily basis I drive approx. 30 miles to work and another 30
back. That's about 2 x 45 minutes of constant drive on highway. Speed is
between 60-80mph and even turbine is idle as I drive in 5th gear at
around 2500-3000 rpm. That should produce minimal load on any car
segment.

Engine rpm, in itself, has little bearing on differential wear, I think.

The faster you go, or in other words the faster the parts move in
the differential, the more heat is produced. The cycle of wear looks
something like this: heat weakens metal > forces pushing on
metal cause microscopic chips to form > tiny metal flakes start
circulating in the oil further damaging/chipping into already existing
damage. It is important to change the oil to get rid of the
microscopic floating metal debris.

I think 60 mph speed would cause only regular wear, but 80mph
for prolong periods of time, and if done in hot weather, may cause
some additional, or accelerated wear. How much in terms of longevity
of differential? Who knows?

It may be just bad luck. Likely some initial large crack or chip,
perhaps from stresses of very rapid acceleration initiated an accelerated
'metal wear cycle.' Was the WRX floored frequently or used for towing
especially on rough surfaces which produce jerking motion? - this can
put a lot of stress on gears and badly undermine both a differential and
a transmission.

MN

 

[MN]

Should have read:

Was the WRX floored frequently or _E VE R_ used for towing
especially on rough surfaces which produce jerking motion? - this
can put a lot of stress on gears and badly undermine both a differential
and a transmission.

MN

 

[SuperPoo]

Just got my '02 WRX Wagon (manual shift) from service. My pocket is
lighter for exactly US$1100 (parts+labor) after replacing center
differential (63k miles on car). What I'd really like to hear is other's
experiences with this problem. When asking service guy what might caused
this problem he was constantly asking if I was having diferent tire size
(never) or overheating CD by driving in extreme conditions (what's
extreme in regular day-to-day drive, 80% highway!?). Other than that he
didn't have any clue and didn't find anything unusual. He was a bit
surprised having in mind car mileage. This is most likely to be expected
after 100k miles. Anyway, I felt pissed. My opinion is that CD is a bit
more robust and not that prone to overheat/failure in regular driving
conditions.

Does anybody else have similar experience or any knowledge of similar
problem to share? Originaly, I noticed a problem as
'grinding/pulsating' when having wheel turned to lock position and
slowly moving (usually when coming to or leaving a parking spot).
Problem is definitely resolved now after repair but I'd still like to
know what exactly might cause this.

No ideas here, you're the first I have heard of with center diff problems.
If any WRX should have trouble it should be my '02 wagon. It has just under
80k and has been hit three times, heavily abused (high RPM launches, power
slides, long distances at sustained high speeds and I am terrible at keeping
on top of maintenance.) and so far no issues with the tranny or anything
else for that matter. Only things replaced so far tires, brakes and the
clutch. I do however go through allot of oil-- 2 quarts every 5k or so. I
attribute it to the fact the car spends so much time at high RPMs, because
it is not leaking and the car makes no visible smoke.

Seems like just bad luck for you.

Steve

 

[Black WRX]

Should have read:

Was the WRX floored frequently or _E VE R_ used for towing
especially on rough surfaces which produce jerking motion? - this
can put a lot of stress on gears and badly undermine both a differential
and a transmission.

MN

Well, I wasn't granny behind the wheel but none of my driving was so
crazy to ruin the car. No racetrack shenanigans, no drop-clutch...etc.
After all I bought it new to last some time and always tried not to
abuse it. My clutch is still in perfect shape after 65k. Only brake pads
were changed once at about 35K (it's about time to change them again)
and tires twice at 30K and again recently. Seems like I just had a bad
luck...Since I started driving, some 15 years ago, all my cars were mid-
level performance cars. I had Lancia Delta Integrale long ago and that
baby was really abused (young&crazy) but never had such fatal
problem....

 

[Black WRX]

No ideas here, you're the first I have heard of with center diff problems.
If any WRX should have trouble it should be my '02 wagon. It has just under
80k and has been hit three times, heavily abused (high RPM launches, power
slides, long distances at sustained high speeds and I am terrible at keeping
on top of maintenance.) and so far no issues with the tranny or anything
else for that matter. Only things replaced so far tires, brakes and the
clutch. I do however go through allot of oil-- 2 quarts every 5k or so. I
attribute it to the fact the car spends so much time at high RPMs, because
it is not leaking and the car makes no visible smoke.

Seems like just bad luck for you.

Steve

Yep. Seems like a bad luck. Anyway, I had opinion that this car is a bit
more robust than other Scoobies and some parts are meant to be less
prone to wear and tear. After all they market this one as a 'performance
car' (besides STI). AS manufacturer, you shouldn't expect that people
buying this car will not try to step on a bit harder and turn wheel with
more enthusiasm....

 

[MN]

Well, I wasn't granny behind the wheel but none of my driving was so
crazy to ruin the car. No racetrack shenanigans, no drop-clutch...etc.
After all I bought it new to last some time and always tried not to
abuse it. My clutch is still in perfect shape after 65k. Only brake pads
were changed once at about 35K (it's about time to change them again)
and tires twice at 30K and again recently. Seems like I just had a bad
luck...

That's probably it, bad luck, whatever it was.

I can't think of anything else, besides perhaps a misdiagnosis.
Whas the differential really broke? If replacing it cured the
problem then probably yes. You haven't described the initial
symptoms. The last step is just trust in ones mechanic, right.
Was he telling the truth, is there really a new differential in my
car, etc?

Well, I think I covered all the angles. In any case, bad luck
can also be defined as when your pocketbook gets hit. So
either, way you had bad luck.

MN

 

[MN]

That's probably it, bad luck, whatever it was.

I can't think of anything else, besides perhaps a misdiagnosis.
Whas the differential really broke? If replacing it cured the
problem then probably yes. You haven't described the initial
symptoms.

Sorry you did:

Originaly, I noticed a problem as 'grinding/pulsating' when
having wheel turned to lock position and slowly moving
(usually when coming to or leaving a parking spot). Problem
is definitely resolved now... .

Might have been the differential, indeed.

MN

 

[Carl 1 Lucky Texan]

Well, I wasn't granny behind the wheel but none of my driving was so
crazy to ruin the car. No racetrack shenanigans, no drop-clutch...etc.
After all I bought it new to last some time and always tried not to
abuse it. My clutch is still in perfect shape after 65k. Only brake pads
were changed once at about 35K (it's about time to change them again)
and tires twice at 30K and again recently. Seems like I just had a bad
luck...Since I started driving, some 15 years ago, all my cars were mid-
level performance cars. I had Lancia Delta Integrale long ago and that
baby was really abused (young&crazy) but never had such fatal
problem....

Typically, a tire issue would be involved in the premature failure of
the CD. frequent heavy cargo without increasing rear tire pressure,
mixing in 1 or 2 new tires with older, slick tires, running on a low or
'donut' tire, possibly some maintanece confusion about fluids - I've
read of that happening. very odd.

I DO NOT feel extended highway driving with all other factors being
positive could lead to this. I believe a Subaru Forester even holds the
world 'endurance' record.

Carl

 

[MN]

I DO NOT feel extended highway driving with all other factors being
positive could lead to this. I believe a Subaru Forester even holds the
world 'endurance' record.

If its high-speed hours upon hours I think it can have
a significant detrimental effect. Try touching the rear
differential after driving for half an hour, or so, at 70mph.
Its hot, very, very, hot, I might add. If you happen to
go more than 70 mph then the effect is even worse.
Same goes for the front diff, although I have never
touched the front. No wonder Subaru put cooling fins
on these two parts.

MN

 

[Carl 1 Lucky Texan]

If its high-speed hours upon hours I think it can have
a significant detrimental effect. Try touching the rear
differential after driving for half an hour, or so, at 70mph.
Its hot, very, very, hot, I might add. If you happen to
go more than 70 mph then the effect is even worse.
Same goes for the front diff, although I have never
touched the front. No wonder Subaru put cooling fins
on these two parts.

MN

Wouldn't the same be true of any car's diff? I dunno, it didn't seem to
concern the aforementioned endurance run(averaging over 100mph for a
24hr period);
http://www.subaru-global.com/about/history/1996-001.html

Carl

 

[mulder]

Hmm...on a daily basis I drive approx. 30 miles to work and another 30
back. That's about 2 x 45 minutes of constant drive on highway. Speed is
between 60-80mph and even turbine is idle as I drive in 5th gear at
around 2500-3000 rpm. That should produce minimal load on any car
segment. If differential fluid caused a problem I have to thank service
personell. Since I bought this car back in '01 I didn't miss a single
oil change or any other scheduled service as suggested by manufacturer.
I even keep service history on MySubaru website. Have to check if tranny
fluid was ever changed.

FYI both the center and rear LSD differentials on the WRX are
viscous-coupling type units and are sealed. They do not have any
contact with the gear oil/fluid and any contaminants in the fluid will
not reach the actual differential. About the only thing that will kill
these prematurely, aside from a defect or abusive driving, is unequal
rolling circumference between the wheels caused by uneven tire wear or
different size/brand tires being mixed on the same vehicle.

 

[Black WRX]

If its high-speed hours upon hours I think it can have
a significant detrimental effect. Try touching the rear
differential after driving for half an hour, or so, at 70mph.
Its hot, very, very, hot, I might add. If you happen to
go more than 70 mph then the effect is even worse.
Same goes for the front diff, although I have never
touched the front. No wonder Subaru put cooling fins
on these two parts.

MN

If this statement is really truth, I shouldn't be even making longer
highway trip with this car but only use it for frocery shopping. I'm not
buying this. That would make a really bad spot on Subaru's marketing
campaign. I find them really reliable and well made vehicles despite
this problem I recently had. Let's call it plain bad luck issue. Maybe I
should visit Vegas and find out if I'll do better in gambling..