05+ Driving on thin ice/snow

[outahere]

Not really. It's more an issue of updating the suspension to a newer and better design. I doubt Subaru would say their BP/BL vehicles have handling issues. This thread was finally dead too.

 

From the 2010 Legacy press release:

 

"......A new double-wishbone rear suspension, mounted to a sub frame, replaces the previous multi-link configuration to provide improved ride, stability and handling......"

[RJS5689]

From the 2010 Legacy press release:

 

"......A new double-wishbone rear suspension, mounted to a sub frame, replaces the previous multi-link configuration to provide improved ride, stability and handling......"

Sure an updated design will help stability, but that's not the sole reason they do it. You claim that they acknowledged there was a handling problem, but there wasn't. It was just a different suspension design. Not every vehicle with a multi-link setup has this "issue" which I don't even notice.

[BAC5.2]

It's because it's an auto.

[ehsnils]

Most Outback owners only experienced this problem when the vehicle was loaded with 4-5 passengers and gear in the back. To alleviate the problem of winter time rear instability on straight roads, some owners have had their rear toe set at zero, with a load in the back. Having rear toe set at zero with an unloaded vehicle did not solve the problem.

 

Makes sense, so we'll see what the upgrade does.

[UCDlgt]

uhhh, slow down?

 

50 on black ice?!

[UCDlgt]

oh, and buy some nokian wrg2's...they are da bomb.

[Richard B.]

i think its the rear lsd forcing power to the wheels.

[TimGinCentralNJ]

Not really. It's more an issue of updating the suspension to a newer and better design. I doubt Subaru would say their BP/BL vehicles have handling issues. This thread was finally dead too.

 

+1.

 

IMO, they've got "nowhere to go but up" on their suspension design on the current gen OB. I've driven older OBs and the design introduced with the MY 2005 OB was a definite step in the wrong direction...most likely in a feeble attempt to do what Audi did with pneumatic suspension on the Allroad only without the cost and complication. Hopefully they'll get it right this time.

 

Tim

[TimGinCentralNJ]

i think its the rear lsd forcing power to the wheels.

 

 

Finally, someone agrees with me!

 

I know this board never came to a definitive answer on this issue, but personally I believe it's the LSD shifting torque from side to side on slippery surfaces--and possibly (at least on auto trans) compounded by the shifting of torque from front to rear, too.

 

Having driving a buddy's old bmw on packed snow once, I remember feeling the rear lsd shifting power from wheel to wheel back and forth making the tail want to flip out in either direction even though I was driving with a steady foot, in a straight line on a flat surface. Based on my experience at least, this is the most plausible explanation.

 

Tim

[BAC5.2]

1) The problem is because it's an auto. Drive any newer automatic Subaru and you get the same thing. The 5MT's don't have that problem, or not to the same extent as the automatic guys.

 

2) The current OB suspension was unveiled in 2000. The multilink rear suspension hasn't changed very much.

[TimGinCentralNJ]

If it doesn't feel any back torque it will shoot power to the opposite side and look for traction there. If there isn't enough traction on that wheel, the diff becomes confused and will continually shift power between the two front wheels looking for traction causing a really unsettling 'wiggle' until one of the fronts once again finds traction.

 

Bingo! I think you've got it....

 

It's the rear LSD becoming "confused" and shifting torque from side to side because it can't find enough traction on either wheel. The result is, the rear wheel which is receiving the majority of torque at that moment briefly loses what little traction it has making it feel like the rear of the car wants to break loose. Now imagine this happening from side to side every few seconds....it would feel like your rear end can't stick to the road.

 

This is one of the reasons why most hard-core off-roaders won't use traction differentials which they cannot fully engage or disengage manually. Sometimes having a rear wheel spin will allow the vehicle to maintain its direction whereas a traction differential--because it's designed to automatically try and find a wheel with traction to move the torque to--can cause both rear wheels to lose traction, causing the vehical's rear end to spin out....possibly at a really bad time...say when you're on the edge of a cliff

 

Tim

 

Tim

[TimGinCentralNJ]

1) The current OB suspension was unveiled in 2000. The multilink rear suspension hasn't changed very much.

 

Perhaps the overall "design" hasn't changed significantly from 2000 to the current gen OBs, but the "execution" of that design on MY 2005 and newer cars is a whole different story. Being both under-sprung and under-dampened are not characteristics of any of the pre-2005 models I've ever driven.

 

Tim

[BAC5.2]

LSD's don't shift power from side to side. They simply lock and unlock (and for the viscous varieties, an infinite range in between). They don't actively hunt for traction. They passively couple the rear wheels together when more slip occurs on one wheel than the other.

 

Still, the fundamental issue comes from the automatic transmission. Either that, or a lack of driver experience. I know none of the 5MT Subaru's I've ever had have been "wiggly" or "unsafe" feeling, and driving my wife's 09 Impreza (which has an automatic) in the snow this year definitely feels less stable than my car.

[TimGinCentralNJ]

LSD's don't shift power from side to side. They simply lock and unlock (and for the viscous varieties, an infinite range in between). They don't actively hunt for traction. They passively couple the rear wheels together when more slip occurs on one wheel than the other..

 

Agreed. Clutch or viscous type LSDs don't "hunt" for traction, but when wheel spin is detected intermittently on each wheel, the act of engaging internal clutches to bind both wheels together does technically result in the transfer of torque from the wheel with the most wheel spin (because torque cannot exist where traction does not exist) to the wheel with the least wheel spin. On a slippery surface where both wheels have poor traction, the act of an LSD locking and unlocking will often cause both rear wheels to lose traction at the same time. Hopefully that clarifies my comment a little better.

 

Still, the fundamental issue comes from the automatic transmission. Either that, or a lack of driver experience. I know none of the 5MT Subaru's I've ever had have been "wiggly" or "unsafe" feeling, and driving my wife's 09 Impreza (which has an automatic) in the snow this year definitely feels less stable than my car.

 

Yeah, I can't say that I've run across this on my manual trans 2005 OBXT either. Yes, I've had the rear slide out before, but only in turns on slipper surfaces where I've applied throttle and shouldn't have.

[iyalla]

i think its the rear lsd forcing power to the wheels.

 

+1 I too think its the LSD effect. Its the reason why Outback owners are complaining about this more than 2.5i Legacy wagon owners. We've had several LGT owners end up in unrecoverable spins here haven't we??. Yeah they made a mistake but still the LSD didn't help.

 

Does anyone think that putting on winter tires would exaggerate the effect...no??

 

Some manufacturers with electronically controlled LSD's disengage them above a certain speed because of unpredictability like this. Good news is the subaru LSD will get weaker over time and it will probably "feel" better

[RJS5689]

+1 I too think its the LSD effect. Its the reason why Outback owners are complaining about this more than 2.5i Legacy wagon owners. We've had several LGT owners end up in unrecoverable spins here haven't we??. Yeah they made a mistake but still the LSD didn't help.

 

Does anyone think that putting on winter tires would exaggerate the effect...no??

 

Some manufacturers with electronically controlled LSD's disengage them above a certain speed because of unpredictability like this. Good news is the subaru LSD will get weaker over time and it will probably "feel" better

Do you experience this problem? I would think 4EAT owners wouldn't, as their vehicles are FWD cars for the most part until there is slippage in the rear, in which case clutch packs are used to transfer power. They lack a rear LSD. I've driven a 4EAT in the bad snow before. They remind me of my last vehicle, a front driver, until the power shifts. They handle pretty funky actually.

[LongHiway]

The backend breaking away or, trying to overtake the front end happend to me once - 4 spd Auto. I was coming off the highway during a heavy rain and hydro-planed on the ramp - temps way above freezing.

 

I came off the gas pretty quick but, the brakes ended up saving me as I ended up sliding sideways for, maybe 10 yards.

 

IMHO, the center transmission couldn't figure out what to do. A few months later I found out the factory alignment was crap and one of the rear tires was bald on the inside which did not help either.

[sschmelcke]

my wifes 2.5i legacy 4eat has the same symptoms just not as pronounced. no rear lsd but if you give it to much gas the rear end will come out on you while not turning. my 2001 forester 4eat had a rear lsd and did the same thing. im pretty sure its the automatic tranny that does this.

[welby]

I haven't noticed any issues at all. I find the car really predictable and stable, actually. I think some people like to blame quirky behavior on vehicles, when it's their own style of driving and/or lack of mechanical knowledge that is causing the problem.

Anything with a rear LSD is going to be more tail happy in the back than something that is open. It's up to the driver to adapt to the mannerisms of the car and adjust their driving accordingly. If not, don't blame the car when you wind up in a ditch.

[iyalla]

Do you experience this problem? I would think 4EAT owners wouldn't, as their vehicles are FWD cars for the most part until there is slippage in the rear, in which case clutch packs are used to transfer power. They lack a rear LSD. I've driven a 4EAT in the bad snow before. They remind me of my last vehicle, a front driver, until the power shifts. They handle pretty funky actually.

 

Nope I don't experience it at all. The only time my 2.5i experiences a problem is when I make a sharp turn on snow and give it gas. The front wheel tries to slip and "plow", but the power is instantly transferred to the back. If you are not ready for it the back will step out EASILY

I have driven in a car with a rear LSD in a straight line and the car would do a sort of waddle as it fights for grip. Very pronounced on an uphill climb in slippery conditions. My 2.5i with no LSD is very smooth in a straight line in slippery weather.

 

There are two things being discussed on this thread it seems One is the LSD waddle that the Outback owners and some LGT owners get, the other is the stepping out that all non-VDC subaru's get. If you get your front wheels into a situation that would cause plowing if the car was a front wheel drive car, like turning on ice, subaru awd will transfer power to the rear and catch you by surprise especially if the back is also on slippery surface, it will whip around or sideways. A FWD car will just plow straight.

 

Just slow down! Cut the gas. Especially on turns If you have plenty of room just keep on the gas, turn into the slide and power your way out of it, rally style. Unfortunately it usually raises its ugly head in confined single lane roads

Edited April 13, 2009 by iyalla

[outahere]

Makes sense, so we'll see what the upgrade does.

 

Do the 2005 and later Outbacks in your part of Europe have a self-leveling rear suspension?

[Fugaziiv]

If you have plenty of room just keep on the gas, turn into the slide and power your way out of it, rally style.

 

Last I checked, this is the ONLY way to drive in the snow.

[DukeTrout]

It's certainly the right way to have fun!

[BAC5.2]

Do you experience this problem? I would think 4EAT owners wouldn't, as their vehicles are FWD cars for the most part until there is slippage in the rear, in which case clutch packs are used to transfer power. They lack a rear LSD. I've driven a 4EAT in the bad snow before. They remind me of my last vehicle, a front driver, until the power shifts. They handle pretty funky actually.

 

4EAT and 5EAT are both VTD cars now. The days of MPT clutch packs are gone. They all default at 55/45 now.

[sschmelcke]

my wifes 2005 2.5i does not have vtd and is a 90/10 split. also no rear lsd. only the 5speed autos in the 3.0 and 2.5gt/xt have vtd. now the 2010's might have vtd but they also only come with a cvt.