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I'm shopping for an '05-'09 Outback. My wife and I live in Vermont and have a 14 month old daughter. I have lots and lots of backroad-rally experience, but my wife is just about to get her driver's license for the first time, at age 38 :)

Seems like VDC would be a good idea. From what I can gather it came on the LLBean 3.0R models in 2007 and 2008, then came stock on all models in 2009. Is that correct? I wasn't paying attention to the turbo models as the word turbo is not in my vocabulary anymore :)

Can the VDC (and traction control) be disabled on all models that have it?

Also want a limited slip. From what I've read it sounds like if the car has heated seats then it has a limited slip?

Thanks for any info :29:
 

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2006 Outback 2.5i Limited 5MT, 1984 Porsche 944
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If the VDC came on all models in 2009, then I would get a 2009 Limited. This will give you VDC, Limited Slip, and the 4cyl for better fuel economy. You can also get it in a manual transmission if you want it.

NVM, manuals can't get VDC.
 

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Probably find all the basic information on which-cars-had-what at Subaru Research Site- specs, prices, options, 2013, 2012, 2011, 2010, 2009.. Outback, Legacy, Forester, Impreza, Tribeca, BRZ, XV. It's a site many rely on; however, there could be some differences. The site is based mainly on the product produced/marketed by Subaru of America. The New England Subaru Dealers group have been known to alter the line up of options/accessories for cars they market in their geographic area. I don't think it would affect the power train, such as whether or not a model included a limited slip rear differential, but it's possible.
 

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Are there aftermarket limited slips available?
Perhaps, but I've never come across it. Any differential would have to be matched in final gear ratio to the other (there's two), and would have to fit in the space provided.

But if the car has a properly-working VDC/TC system, LSD is redundent in most (but perhaps not all) situations.
 

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The limited slip is part of the col weather package. So, if the car has heated mirrors, wiper blade area on the windshield and heated seat, it will have have limited slip.

For 09, anything above the base model had the cold weather package.
For 08 anything with Limited or LLBean will have the VDC and cold weather pack.

The tires will have more effect then any electonics. So, spend your money on tire with good traction.
 

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I have pretty much basic model end of 2005 (same as 2006) it has heated seats, windshield and mirrors. I'we been told by dealer/service that it has limited slip rear. They were adding limited slip additive to rear dif when replacing oil. Now, I'm not sure if it does have it or not. if it does have it, it is useless. When I had diagonal wheels up in the air, on hard surface off road, I couldn't go fw nor backwards. Had to get out of the car, and push it. : ) Ridiculous.
Stability control is the different story, and in my case it is "misfiring" when driving over frozen streaks of water (from melting snow on the side of the road, from earlier in the day) Would cause rear end to uncomfortably twitch. But it would tend to believe, that in situations for which this system is designed for, it would work properly.
 

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(formerly) 03 H6 OBW , (presently) 06 WRX Sportwagon & 2021 Honda CR-V
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I have pretty much basic model end of 2005 (same as 2006) it has heated seats, windshield and mirrors. I'we been told by dealer/service that it has limited slip rear. They were adding limited slip additive to rear dif when replacing oil. Now, I'm not sure if it does have it or not. if it does have it, it is useless. When I had diagonal wheels up in the air, on hard surface off road, I couldn't go fw nor backwards. Had to get out of the car, and push it. : ) Ridiculous.
Stability control is the different story, and in my case it is "misfiring" when driving over frozen streaks of water (from melting snow on the side of the road, from earlier in the day) Would cause rear end to uncomfortably twitch. But it would tend to believe, that in situations for which this system is designed for, it would work properly.
Some folks say even the viscous LSD is no good after about 60K miles. My wife's 03 H6 has the AWP. I've had the rear up a coupla times and, when I turn one wheel, the opposite wheel turns in the same direction. Her car has 70K. Certainly, I have no idea if the lsd 'works' under load anymore.

And it gets regula GL5 fluid so - dunno what your mechanic was on about.

Try testing you rear diff like i did. Open diff will move the other side in the opposit direction. LSD should move it the same direction.
 

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At 55K the limited slip on my '03 H6 was completely useless.

I think not only would limited-slip not help with VDC, I think VDC requires there be no limited slip.
 

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I think not only would limited-slip not help with VDC, I think VDC requires there be no limited slip.

yeah, this seems correct from my limited knowledge. VDC also should work at all 4 corners, potentially better than open diff front and viscous rear I'd think.


**********When I had diagonal wheels up in the air, on hard surface off road, I couldn't go fw nor backwards. Had to get out of the car, and push it. : ) ******************

You might try some light, on-off brake application with the throttle next time this happens. It can help transfer some torque to a wheel with grip.
 

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Don't get hung up on diffs, it is easy to get excited about awesome LSDs and all the cool AWD-ing you'll be doing, but really the Subaru AWD system is just fine, and with VDC and some good tires you are set. With the VDC you get more than some help getting going, it will save you from spinning out, help you stay on course etc.

I would say a Subaru with aggressive LSDs is going to be more difficult to drive. The viscous LSDs that subaru uses, especially the rear one are very gentle, just enough to get you some traction when wheels are spinning. The VDC system is beyond this, it acts on all 4 wheels, there is really no need for the weak little rear viscous LSD in a VDC Subaru though some still have it but Subaru has generally dropped it in VDC cars.

You might try some light, on-off brake application with the throttle next time this happens. It can help transfer some torque to a wheel with grip.
That "brake trick" is for Torsen LSDs that bias torque. viscous LSDs only need wheel motion, like a spinning wheel, to take action.

I think not only would limited-slip not help with VDC, I think VDC requires there be no limited slip.
VDC can work fine with LSDs, take a look at the 08+ STI. There is likely some complimentary programming in the brain but it works great.
 

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From what I've read, Brake-throttle modulation can work in an emergency with open diffs.

not sure why you'd need it with working torsen or other lsds.



But I can't speak from experience so, maybe you're right. I know I'd try it.
 

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From what I've read, Brake-throttle modulation can work in an emergency with open diffs.

not sure why you'd need it with working torsen or other lsds.

But I can't speak from experience so, maybe you're right. I know I'd try it.
Anything is worth a try if you are stuck!

Can't really explain the deal with getting technical, I'll try quickly

A Torsen diff is unique, it biases torque, meaning the torque to the gripping wheel is a multiple of the torque to the slipping wheel. The Torsen requires no wheelspin, it is TORque SENsing see what they did there? A Torsen diff is rated on the biasing ratio, say 4:1 indicating a 4 times the torque of biasing action from the slipping wheel to the gripping wheel. That unique operating principle is the Torsen "Achile's Heel" as if you had one wheel in the air on an axle, the torque to move that wheel is essentially none*. Well 4x0=0 so the biasing action results in no torque transferred across the axle.

Now...if you were to say brake both wheels on an axle with one wheel in the air, the torque to overcome the brake, say it is 20 lb-ft each side. Now the force to move the wheel in the air is 20ft-lb. On a 4:1 bias ratio, 80 ft-lb now goes to the other wheel. 20 ft-lb to overcome the brake, 60 left over to move the Hummer and now you are unstuck.

OK now open diff. The open diff transfers the same power to both wheels at all times. If the wheel in the air take 0 ft-lb to move, the wheel on the ground gets 0 ft-lb too*. So think of the open diff like a Torsen with a 1:1 bias ratio to get through this example. So same as above, you are stuck and you brake both wheels on the axle, 20lb-ft to overcome the brake, so 20lb-ft is applied to the wheel on the ground...but you need the same 20 lb-ft to overcome the brake. 20-20=0 so you are right back where you started...still stuck.

Now this dovetails perfectly with VDC...see the VDC unlike you or I, can brake just one wheel at a time, so 20lb-ft could easily be transferred across the axle from the airborne wheel to an free wheel on the ground.

The viscous diff, it relies on wheel speed difference. The stock Subaru center transfers 29lb-ft per 100 RPM speed difference. 100 RPM is a lot, hence it only works on a slippery surface or if you are very aggressive like on a race track, and even then not very well. You have to have wheelspin, braking would just operate a viscous like an open diff so the case could be made if you have the 5MT braking all wheels would be counterproductive.

In the real world I'd give this a try, especially front to rear due to brake proportioning.

Oh well gotta run hope that helps.

*Drivetrain friction will always take some torque to overcome you are never at "zero" but I just use this for the sake of simplicity in the example.
 

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Can you get the limited slip rebuilt for the rear? In a 08 outback 2.5i?
I'm sure it can be rebuilt or replaced, but I'll say that after reading a lot of this board over the past 2 years there's almost no discussion of it. I think most OB owners are unaware that the majority of pre-2010 outbacks had one, what it did for them, or that it probably stopped working a while back.
 

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I'm sure it can be rebuilt or replaced, but I'll say that after reading a lot of this board over the past 2 years there's almost no discussion of it. I think most OB owners are unaware that the majority of pre-2010 outbacks had one, what it did for them, or that it probably stopped working a while back.
After much googleing i cant find much info on it, besides some sti lsd types
 

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user 'ivan' over at USMB has reworked some viscous center diffs I think, maybe he's also worked on rear diffs?
 

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Well, maybe they do and maybe they don't.

Bought mine with 55k on it and the rear limited slip has never worked the slightest bit.

It is possible the previous owner baked it somehow, but thart's not so easy in 55k.
 
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