Locking, limited-slip, and positrac

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Torsen was my favorite they were OEM in 2002 ranger fx4 and 2003+ fx4 level2

Lockers will kill you in winter, limited slip will get you moving. but spinning both tires will tend to wreck you on ice.

The wimpy brake style limited slip is ideal for winter on the road.


Almost all the best offroad gear is terrible on road.. unless you are going 10mph in the mountains.
 
Originally Posted By: Rand
Torsen was my favorite they were OEM in 2002 ranger fx4 and 2003+ fx4 level2


My '14 has a Torsen T-2 from the factory. I really like it, gives the perfect amount of slip before locking.
 
Originally Posted By: bdcardinal

My '14 has a Torsen T-2 from the factory. I really like it, gives the perfect amount of slip before locking.


I'm probably being a bit pedantic, but the Torsen never "locks" and it is "always on". Good video on how it works:

https://www.youtube.com/watch?v=lDsQAs0Ldes

robert
 
Originally Posted By: robertcope
Originally Posted By: bdcardinal

My '14 has a Torsen T-2 from the factory. I really like it, gives the perfect amount of slip before locking.


I'm probably being a bit pedantic, but the Torsen never "locks" and it is "always on". Good video on how it works:

https://www.youtube.com/watch?v=lDsQAs0Ldes

robert


once the TBR is met it "locks" iirc
 
Originally Posted By: robertcope
LSD doesn't always have a clutch. Many cars have mechanical units, usually Torsens. The downside to a Torsen is that both wheels have to have some traction for it to work; if you lift a wheel, it acts as an open diff. They also can't be tuned, really. The upside is they don't wear out.

robert


Torsen is beyond useless on something truly slippery. Try relying on a Torsen to get you up an algae covered boat ramp, and you're done.
 
No snow here - but boat ramps, deep sand, mud, dirt ... GM G80's sense spin and lock up both wheels until you remove pressure. On the road - you never know they are lockers ...

I like to punch it on a wet dirt road once in a while to verify "two stripes" ...
 
Originally Posted By: DoubleWasp
Originally Posted By: robertcope
LSD doesn't always have a clutch. Many cars have mechanical units, usually Torsens. The downside to a Torsen is that both wheels have to have some traction for it to work; if you lift a wheel, it acts as an open diff. They also can't be tuned, really. The upside is they don't wear out.

robert


Torsen is beyond useless on something truly slippery. Try relying on a Torsen to get you up an algae covered boat ramp, and you're done.


Does the limited slip S spring give you a bit of traction in a situation like that?
 
Originally Posted By: 4WD
GM G80's sense spin and lock up both wheels until you remove pressure. On the road - you never know they are lockers ...

I like to punch it on a wet dirt road once in a while to verify "two stripes" ...


They get a bad-rap from some, but the Eaton MLocker is very effective. Slip, clunk into place, and on you go:

http://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/mlocker/index.htm#tabs-1


Here's comparing that to a Mazda AWD system. Very different results:
 
Good example of what they are made for - slow speed assist -perhaps the parking lot drifter and "donut" crowd should change them out ...
 
Originally Posted By: ford46guy

Does the limited slip S spring give you a bit of traction in a situation like that?


Negative. The ticket in those situations is to give a little brake application to force power toward the other wheel. Then, once both wheels are turning close enough to eachother, they'll kind of grip.
 
Originally Posted By: FlyNavyP3
I'll take a stab at this...

An open differential will allow one tire to turn slower than the drivetrain but never faster, so in a corner it's actually powering the outer wheel. When one tire starts to spin it doesn't get all the torque, the other tire gets exactly the same torque applied to it. For example one tire on ice the other tire on dry pavement. The tire on the ice spins and the tire on the pavement gets exactly the same torque as it takes to spin the tire on the ice.

Limited slip uses many different methods to accomplish the task of limiting the differential action between one axle and the other. It does this through clutches (either cone or plate) or via helical gears. When one tire starts to turn faster than the other the force of the spider gears turning aided by spring preload helps transfer torque to the wheel with more traction. In a helical gear differential the bias ratio does the same thing without clutches.

Mechanical locking differential will allow a tire to turn faster than the drivetrain but never slower. Going around a corner it will always be powering the inside tire. These usually use some sort of locking tooth design with springs to disengage when torque isn't applied to the axle.


An open differential has a set of spider gears that allow the inner and outer wheels to split the difference. the inner wheel will turn slower, while the outer wheel turns faster. in low traction situations the inner tire will generally slip due to weight transfer.
 
Subaru used to use LSD in rear often however software and skid/traction control it likely just cheaper to apply a brake slightly. Even expensive cars like BMW 2 series take this approach....
 
Originally Posted By: Ramblejam
Originally Posted By: 4WD
GM G80's sense spin and lock up both wheels until you remove pressure. On the road - you never know they are lockers ...

I like to punch it on a wet dirt road once in a while to verify "two stripes" ...


They get a bad-rap from some, but the Eaton MLocker is very effective. Slip, clunk into place, and on you go:

http://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/mlocker/index.htm#tabs-1


Here's comparing that to a Mazda AWD system. Very different results:



I love my G80!
 
Shannow,or anyone else knowledgeable about Torsen Differentials:

What type of a driving situation does a Torsen Differential help with? I'm just trying to figure out is it more for ice traction, good traction for a car driven on a road course, straight line dry traction? What is the benefit of having a vehicle with a Torsen Differential?
 
Advantage is that they are seamless in their differnetiation, just like an open wheeler, so you don't get the axle wind-up and clunks tht you get woth regular LSD, nor the on/off action of a locker.

I've not seen/experienced them not working with one wheel on ice, one on tarmac, but haven't looked either, and certainly would hardly ever see it in Oz.

Was a device that I was fascinated in the gear design back at Uni, and was installed in the Vector W2 as the first time I saw it applied.
 
Originally Posted By: Shannow
Advantage is that they are seamless in their differnetiation, just like an open wheeler, so you don't get the axle wind-up and clunks tht you get woth regular LSD, nor the on/off action of a locker.

I've not seen/experienced them not working with one wheel on ice, one on tarmac, but haven't looked either, and certainly would hardly ever see it in Oz.

Was a device that I was fascinated in the gear design back at Uni, and was installed in the Vector W2 as the first time I saw it applied.


I really really enjoy the Torsen in my Mustang. I have driven other 13-14 GTs with the regular "Trac-loc" clutch type differential and it isn't the same.

Funny story, one of my teachers when I was in school for Automotive worked for Vector. He said he got out real quick when all the white powder money appeared.
 
Originally Posted By: DoubleWasp
G80's are great, but can have some seriously unpredictable reactions at times.


For instance?
 
Originally Posted By: c502cid
Originally Posted By: DoubleWasp
G80's are great, but can have some seriously unpredictable reactions at times.


For instance?
I'd imagine driveline shock. The spinning wheel has stored energy, and once the locker locks up, it may be enough to break loose traction on the other wheel. Which may allow the rear to kick out, especially one was cornering at the time. Or if there is dissimilar traction to the wheels--vehicle may decide to suddenly change direction.
 
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