Diff Lokka - INFO NEEDED

benwarn

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Sep 29, 2008
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132
Hey all, i've called up an aussie company regarding manufacturing a Locker for the subarus and there is progress.

They now have 2 subaru diffs and axels in the workshop, and are looking how to make a locker for it. There are a few problems however. They're playing with leone diffs and are wondering if these are the same or similar to our forester diffs, and how different they may be? And also which models share the same diff, as in, will the forester locker match and outback etc etc

The other problem is they are an auto locker that disengages on hi traction cornering, I'm not sure quiet how it works but it's not a manual engage. So it'd be easier to use on the auto where you can dissengage the rear diff via a fuse. the other possibility would be to dissengage the tailshaft on the manual model to transfer the power to the front when on the road.

So basically i need a good bit of information i can give to them so they can work out if it's dooable or not, and who'd be iinterested in getting one. I think the proce would be around $700 aussie dollars.

help would be much appreciated:)
 
This was discussed quite a bit before the old forum crashed. here is what I can tell you:

-I'm interested at that price (depending on shipping to the USA)
-As I recall, it is an auto locker (Detroit Locker, Powertrax, etc are similar), so if both wheels are moving the same speed, they are "locked" together. A wheel is allowed to turn faster than the other when the impetus comes from the tire, for example, when turning, the outer wheel is allowed to move faster and free wheels. This can sometimes cause a little bit of oversteer
-Subaru has messed around with how the axles are held into the diff, which I believe is the main difference between most of the different years and models of Subarus. I'm sure someone here can provide more info.
 
benwarn said:
Hey all, i've called up an aussie company regarding manufacturing a Locker for the subarus and there is progress.

They now have 2 subaru diffs and axels in the workshop, and are looking how to make a locker for it. There are a few problems however. They're playing with leone diffs and are wondering if these are the same or similar to our forester diffs, and how different they may be? And also which models share the same diff, as in, will the forester locker match and outback etc etc

The other problem is they are an auto locker that disengages on hi traction cornering, I'm not sure quiet how it works but it's not a manual engage. So it'd be easier to use on the auto where you can dissengage the rear diff via a fuse. the other possibility would be to dissengage the tailshaft on the manual model to transfer the power to the front when on the road.

So basically i need a good bit of information i can give to them so they can work out if it's dooable or not, and who'd be iinterested in getting one. I think the proce would be around $700 aussie dollars.

help would be much appreciated:)
Click to expand...

The unlocking in high torque split demands really is not unusual. That can be done mechanically or electronically and may be defeatable.

What it sounds like is that they arent making a locker, but a TRUE limited slip differentail. This is usually a cone clutch or a clutch pack that is disngaged automatically on curves.

https://en.wikipedia.org/wiki/Limited-slip_differential

I dont think there is enough room in the housing to pack all thjat stuff in there.


nipper
 
I'm interested for sure, as I'm due for a new diff (rear) very soon. The price sounds ok aswell.
The diffs on Forry's in Australia have a 4.444 ratio as far as I'm aware.
However, the ratio on European Forry's (not sure about the U.S) is 4.111, or so I've been led to believe.

nipper said:
What it sounds like is that they arent making a locker, but a TRUE limited slip differentail.
Click to expand...
I'm of the same opinion as nipper.

It sounds, to me, as though the lsd becomes very tight & "almost" acts as a locker when the lsd cuts in.

Regards
Mr Turbo
 
i'm keen for sure. but i'll commit when i see the specs. my 2000 outback is 4:11 ratio. nice chase up though Benwarn. i just need some more info.
 
eden said:
.... but i'll commit when i see the specs.... i just need some more info.
Click to expand...
Agreed.

Hopefully it can be done for both the N/A & be strong enough to be able to cope with the extra power of an XT.

Regards
Mr Turbo
 
Naturally aspirated 2.5L forester's are 4.11 for manuals and 4.44 for autos
XT's are 4.44 manual and auto

not sure about earlier models
 
nipper said:
The unlocking in high torque split demands really is not unusual. That can be done mechanically or electronically and may be defeatable.

What it sounds like is that they arent making a locker, but a TRUE limited slip differentail. This is usually a cone clutch or a clutch pack that is disngaged automatically on curves.

https://en.wikipedia.org/wiki/Limited-slip_differential

I dont think there is enough room in the housing to pack all thjat stuff in there.


nipper
Click to expand...
The Wiki site calls out the Lokka, and has it correct, except for the "locker" link:


Locking differential (Detroit Locker/Lokka
A locker locks both wheels under normal conditions. If a wheel is externally forced to rotate faster than the differential centre (i.e., the outer wheel in a corner) the mechanism unlocks that wheel and allows it to turn freely (but only so long as it rotates faster than the centre). Thus the locker has the extremely unusual characteristic of applying drive torque through the inner wheel in corners. Drive shaft input torque causes the pinion cross shaft to lock the centre more firmly, resisting the unlocking action. As the two actions of the mechanism are contradictory, the car will unpredictably alternate between one-wheel and two-wheel drive under power in corners, giving difficult to control handling. As the vehicle goes down a straight line it is locked positive, and as the vehicle enters a curve it is still locked positive. As the vehicle goes farther into the curve, the gear unlocks causing it to jerk.[5] It can be very noisy and is often used in off-road 4WD applications. The traditional American racing differential is a Detroit Locker.
 
MountainBiker said:
The Wiki site calls out the Lokka, and has it correct, except for the "locker" link:


Locking differential (Detroit Locker/Lokka
A locker locks both wheels under normal conditions. If a wheel is externally forced to rotate faster than the differential centre (i.e., the outer wheel in a corner) the mechanism unlocks that wheel and allows it to turn freely (but only so long as it rotates faster than the centre). Thus the locker has the extremely unusual characteristic of applying drive torque through the inner wheel in corners. Drive shaft input torque causes the pinion cross shaft to lock the centre more firmly, resisting the unlocking action. As the two actions of the mechanism are contradictory, the car will unpredictably alternate between one-wheel and two-wheel drive under power in corners, giving difficult to control handling. As the vehicle goes down a straight line it is locked positive, and as the vehicle enters a curve it is still locked positive. As the vehicle goes farther into the curve, the gear unlocks causing it to jerk.[5] It can be very noisy and is often used in off-road 4WD applications. The traditional American racing differential is a Detroit Locker.
Click to expand...

Footnote 5
^ Smith, Carroll (1996). Drive To Win. Carroll Smith Consulting Inc.. Section 7 Page 34. ISBN 0-9651600-0-9. "...a somewhat crude device, noisy and upsetting as it cycles between "on" and "off" at partial or changing throttle... The transition from one wheel to two wheel drive can be particularly upsetting if the driver decides to play with the throttle on corner exit."
 
Perhaps one difference between the Leone diffs (The ones he has must almost be the last ones in existance!) and a Forie is the Forrie diff is viscous LSD, but I am not sure about the Leone diff. I suspect it is open. I would also expect someother differences seeing as one car is 20 years older than the other!
 
Here is some info I had archived when I was talking to a USA manufacturer of locking diffs. It came from Daza on the old site before it crashed, unfortunately, the pics are gone. This is in reference to various R160 rear diffs in Subarus:

"between the L series and you Forrie the diffs changed from having stub axels in the diff to using driveshafts with the stubs attached.
https://vunadewai.com/pics/EarlyDiff.jpg
Early style Diff https://vunadewai.com/pics/EarlyDiff.jpg
and it's shafts https://vunadewai.com/pics/EarlyShaft.jpg
Later diff https://vunadewai.com/pics/LateDiff.jpg
and it's shafts https://vunadewai.com/pics/LateShaft.jpg
So, there's no reason why it wont work but it will probably require some trial and error to find a combination of shafts and CV's to suit.
Daza."
 
One product I've had my eyes on for a while are these aftermarket Quaife LSDs:

STANDARD SPEC
(FRONT) https://www.quaife.co.uk/Subaru-Impreza-Legacy-front-93-00-ATB-differential
(BACK) https://www.quaife.co.uk/Subaru-Impreza-Legacy-not-Sti-rear-ATB-differntial-93-00

As you can see, they use helical gearing (as opposed to plates) resulting in smoother operation. I've also heard that the OEM LSD off the STi does wonders when transplanted to a Forester. Sure they ain't no locker - but they must help somewhat.
 
ok, sorta thread jack. Does any company make a selectable locker? You know, something that goes from full lock in the "on" position to either open or limited slip in the "off" position. I'd love to find something like that for the rear of my Outback.
 
There is an air locker diff- but cannot think of the name of the mob that makes them. Mental blank unfortunately
 
I'd be interested too. Mines a MY01 2.0l auto and I have no idea about diff ratios and things. All I know is locked=good :biggrin: wheel spin=bad :raspberry:
 
Hi Kerri,

With your car, you might want to keep the ratios as they are. There are plated diffs for the rear of your car from STI. No idea about the fronts which are part of the gearbox, and STI only use manuals.

For manual cars, you can get different centre diffs with either 20kg or 11kg centres. This allows greater drive to the half of the car with less grip (front or rear) and replaces the 4kg centre. But it means that handbrake turns cannot be done with the 20kg centre, as applying the handbrake would also lock the front wheels.

It is probably as close as you can get to a locked diff for most people. However, the 05 onwards STI's (or much earlier in Japan) use a DCCD which can also lock up the centre diff. But you would need a Motec controller for the DCCD. Combine the $1500 plus programming plus the gearbox itself for about $8000 and it all starts getting very expensive. And that is assuming your rear diff matches the front, or you will be up for more money again. Of course, you can replace the front helical diff with a plated one for even more money!

So to move away from what you have would not be a cheap option. The auto confuses things as there is not much available for them as far as I know.
 
I know ARB makes TONS of air locker applications, but I doubt there's one for Subaru. What model is a USDM '02 Outback rear diff? It'll be easier to find something if I search for the diff rather than the car.
 
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