'96 5 Speed Center Differential Problems

[jhelm_waterw]

Hi all and thanks for reading.

I have a 96 2.2 AWD Legacy Wagon with a 5 speed which means it uses the
viscous coupled center differential.

Only in the last few months, I have been experiencing the '4WD Scrub'
which means it binds up and shudders when turning a corner (Like my old
switch on the fly locking 4WD Loyale)

This does not happen when the car is cold, only when I have been driving
it for a while (once it is warm/hot). So... the magic silicone fluid that
fills the center diff is getting hot and binding even when it should not.
Please note that I REALLY thought it worked off the same 80w/90 gear oil
that fills the surrounding gearbox/front differential, but I have read
numerous offical subaru dealer notes stating that the center differential
runs off a special silicone fluid.

I have all new matched tires which means that is not the problem.

I'm pretty sure I have just burned off/overheated too much of that magic
silicone fluid or beaten up my center diff towing too many heavy toys.

I was told 'Yep, it is shot. You cannot fix it, just buy a new one ($450).
You have to drop the tranny, pull it apart and replace the diff as a whole
unit'

Is this true? Has anyone heard of this? I have SEARCHED the net and come
up with very few answers. No one really talks about the viscous center
diffs.

Can I replace/refill the silicon fluid?
Are these servicable ?
Can I buy a used one? Where?

Thanks a lot in advance,
Jeremy

 

[Henry Paul]

I have the factory manual for the 1996 2.2 Impreza and it has a section on
the center diff I know. I will look through it and see what I can find for
you. I'm sure they must be similar if not the same.

 

[Henry Paul]

Does not allow binary posts here I guess. I can email you the file if you
like.

 

[Dominic Richens]

I have the _identical_ problem in my 95 5MT 2.2l Legacy - started this
spring after a 500km all hwy drive.

I've done some research; there are a couple of USMB threads on it:
http://www.ultimatesubaru.net/forum/showthread.php?t=12581
http://www.ultimatesubaru.net/forum/showthread.php?t=14992

I ask the "head" mechanic at my Subaru dealership about it and he said that
the VC part of the centre differential is in the process of failing and that
the binding will eventually go away, but I'll be left with an open center
differential (i.e. it won't lock when one wheel spins). He said they charge
950$ CDN and four hours labour, but almost no one ever repairs them because
it takes about 8-10 years for them to fail and by that time no one is
willing to spend that kind of money into a car that otherwise runs just
fine.

He said it is still AWD, in that each tire transmit 25% of the torque when
all wheels have traction, so you're less likely than a FWD car to lose
traction and wind up in the ditch, but once in the ditch you're just as
stuck as a FWD car

 

[Henry Paul]

I wonder if you could find a used transmission at a salvage yard then? Or
perhaps have a specialty transmission shop do the work?

Worst case scenario is you get FWD instead of AWD I guess.

 

[Florian Feuser /FFF/]

I have the _identical_ problem in my 95 5MT 2.2l Legacy - started this
spring after a 500km all hwy drive.

I've done some research; there are a couple of USMB threads on it:
http://www.ultimatesubaru.net/forum/showthread.php?t=12581
http://www.ultimatesubaru.net/forum/showthread.php?t=14992

I've had that same problem with a 95 MT Legacy Wagon as well. I found a used
transmission with 75 k miles for $450 on car-part.com and had it put in for a
few hundred $ more.

The bucking of my Legacy in tight corners was ennerving enough beforehand to
make the investment totally worthwhile.

Florian

 

[Verbs Under My Gel]

Hi all and thanks for reading.

I have a 96 2.2 AWD Legacy Wagon with a 5 speed which means it uses the
viscous coupled center differential.

Only in the last few months, I have been experiencing the '4WD Scrub'
which means it binds up and shudders when turning a corner (Like my old
switch on the fly locking 4WD Loyale)

The difference in circumference between any two tires must not exceed
1/4 inch. Measure the circumference of all four tires.