the 4wd systems lokka, single spins below 15% torque.. so you can drive around slowly and not chirp the tyres.

look i even put a video up on youtube to show... you can clearly hear the clicking noise of the lokka... but no tyre spinning

http://www.youtube.com/watch?v=ByOhsyWQ9kY

I agree that you can drive around slowly with a Lokka and not chirp the tyres, but if the Lokka engaged and disengaged in relation to engine/transmission torque values, it would engage and disengage when the throttle is manipulated. As far as i understand this is not true, it only disengages when one wheel is driven faster than the other by an external force such as the road surface.



Hey, that's a good video, to hear what the noise is like. I was wondering, thanks.

It sounds just like you might expect the cams to sound, as they click past each other while the outside wheel overdrives the diff. It's not a stressed sound. I could only hear it during tight cornering, so either it doesn't disengage on lesser beds, or it can't be heard, or it simply can't be heard by the video camera. Can you respond to that Tocchi? And what's it like to drive on a curvy mountain road, does it upset the handling, or do anything weird under throttle?

Hmm, i might be able to live with the noise after all, living in the country as i do with far less tight cornering than in a city.

How much did it all cost you; Lokka + Ratio change + Labour?

yes very noticeable on tight turns..
long sweeping corners are quieter/softer but just noticeable.

4wd Systems have produced new springs for it. to help eliminate the noise

its pretty comfortable to drive... ive had no handling issues

Lokka - $464 group buy (normally around $600)

to get the Lokka installed with 3.73s it cost $1100 "tilt tray in, drive out" lol

If you fit these softer springs please let us know the difference. I wonder if you go too soft the springs might fail to provide full locking action during the locking process and therefore damage/reduce the life of the cams . . . imagine the cams only partially engaging and therefore suffering from slippage and/or excessive compressive forces.

On a different tone i also wonder if the noise might be loudest in a wagon, then a sedan, then a ute, because of the varying levels of access the sound has to the driver once it passes through the floor?

I travel long mountain roads with tight curves, maybe the noise would be too much.



Okay. Have you ever driven wet and gravel roads hard?

My current thinking on this;

During cornering there is weight transfer from the inside wheels to the outside wheels making the inside driven wheel(s) more likely to spin than the outside driven wheel(s). Once there is wheelspin there is less cornering and less acceleration grip because sliding friction provides less grip than static friction. In a rear drive car there is likelihood for oversteer.

When a car with an open diff turns a corner it is two wheel drive for as long as both driving wheels have traction. This is good. If however there is a traction deficit and a traction difference between the wheels, the diff will revert to one wheel drive. One wheel drive tends to occur because of weight transfer making the inside wheel spin. It may then take some time for it to regain static friction. During this process cornering and acceleration grip will be reduced, handling will be upset, and in a rear drive car there will be a likelihood for oversteer.

When a car with a self-locker turns a corner it is inside wheel driven for as long as the inside wheel has traction, which is not as good as two wheel drive. Worse, weight transfer during cornering gives the inside wheel the least traction potential. In the moment the inside wheel spins, cornering and acceleration grip may be reduced, handling may be upset, and in a rear drive car there may be a likelihood for oversteer. I say 'may' because the inside wheel will slip only a minute amount before the locker engages two wheel drive. Once there is two wheel drive good static friction will usually be attained quickly, which will restore any loss in cornering and acceleration grip, handling, and reduce any oversteer. Achieving drive with the outside wheel assists the cornering process, though this may contribute to oversteer.



Thanks, when i get a quote for an Air Locker i'll compare them.

Still no reply from ARB or Harrop.

The ARB catalogue says;

Air Locker Part no.RD81, suits Ford 8.8", 31 SPL, 31 splines, all ratios
Air Locker Part no.RD82, suits Ford 8.8", 28 SPL, 28 splines, All 'BRNG' refers to carrier bearing inside diameter.

Do falcons have this ford 8.8" diff?

Not sure if thats the correct one, but I remember Zoom magazine fitted an ARB air locker to a BA XR6T, which I'd hazard at a guess at being the 31 spline part you mention.
The 28spline would more then likely be the one, I'd double check it with a phonecall though.

Thanks. I've emailed ARB and Harrop again.


Here's another internet anecdote i've come across:

"ARB lockers are downright dangerous, ok maybe a little harsh but they are not the best for every application. If you lock your diff and park on a clay slope then the airlines can leak and all by sudden your wheels are not locked any more. very dangerous with a tailshaft mounted handbrake or if you just leave the truck in gear. On the other hand they are good cos you can turn them on (if you remember) and off (if you remember) at will, and they are as tough as old boots. but I can think of MUCH better things to spend $1200+ on, like auto lockers or gear type LSDs or a 404 unimog cable actuated locking diff. $10,000 will get you a whole unimog.

The detroit electrac is standard fitment to ford RTV utes, I had one as a work car and they are quite good. Vaccuummee operated ones have the same issues as air operated ones with air lines and s**t which can and will break, but no compressor. Cable operated ones do exist but tend to be from agricultural type vehicles and are not always rated for highway speeds. I think Land Rover had one where you wound a nut on the hub of one wheel and it slid the axle through the diff into the splines on the other side so the diff was completely locked, they were REALLY good apparently. DON'T get cone type LSDs cos they s**t themselves after you turn the corner out of the workshop. Clutch type LSDs are ok but fussy with oil and will wear out after 100,000 MAX with sedate driving (took me less than a month in my EL falcon drifting round local streets).

I am a fan of auto lockers, but not of the front, you will not be able to power out of a tight spot unless it's straight ahead. With an auto locker you just drive the thing, if you buy a new one you can't even hear the clicking when you turn so it won't be an issue. Being a SWB you should take care feeding it power on tight bends especialy with large heavy tyres on because the momentum of one wheel freespinning to catch up to the other can snap things, axles for instance, But with a diesel you won't have to worry about that because it won't free rev as fast as a petrol. You also have to learn how your truck handles on dirt all over again because it will lock up quite frequently, go find a nice big paddock and do some circle work to get used to it. The same is true of any locker though."

And another:

"Auto lockers only lock under power. Plus if the ground is moving one of the wheels faster then the engine is it won't be locked, it will go with the ground, but you will still have the other wheel pushing. If you lift a wheel then it will lock with the other.

For $400 and a 3 year warranty, I would much rather have 9 years minimum of an auto locker then what you get out of an air locker. My only problem with air lockers is with my car (and I think most others here) that is 1/3 of the total cars value. Just on a diff! Don't get my wrong, I do think the ARB air locker is the best, but when you have budgets, you have to think more.

What I suggest, look for people who use auto lockers, as they know what there like. To many people in this world who judge before they have even seen. Roger has looked into this alot. He got two types of reasponces. One from people who have never used auto lockers which goes kinda like this "they are crap, lock up all the time, very annoying, weak, blah" and the one from people who use auto lockers "they are cheap, effective, sometimes clicky, don't effect steering all that much, heaps more traction the LSD, blah blah." Not trying to flame, it's just I am fed up with people talking crap about things they have no idea about. So I'm going to shut up until roger is locked up and going past all of us..

Do you sit there looking at the $30K cinema projector going, that is the only TV worth having? Or do you buy the $3K LCD and be happy?"

A Detroit fan:

"Fishies and donuts are easy as with a Detroit in the rear just so long as you've got power and you aren't on a high traction surface, but they aren't the sort of driving or behaviour that shows a Detroit off to its best effect, nor what we'd expect from a responsible 4Wheeler! And with a Detroit in the rear, you get all the advantages of having a locker, but you've STILL got full differentiation (no need to turn it on or off!), so going downhill is the best of both worlds - BETTER engine braking cos it's to both wheels instead of the hazards encountered if the surface is loose enough for one wheel to turn backwards, but you STILL get to turn at the bottom to avoid the cliff - something that Lokka's really don't like you doing! Tricky climbs, no longer difficult with a Detroit, just feels like a large and powerfull hand in the small of your back just pushing you up the hill!! No need to avoid ruts and very little likelihood of sliding over edges, even if the surface is greasy, cos you will be driving BOTH rear wheels at the same rate, and if you've still got the front steering you go where you are pointed - edge getting near, steer away!

With a Detroit in the rear, you will tend to be way better at driving straight up and down hills, cos the even drive likes an even application, so side slopes can be interesting, just cos you can be driving the car at 45 degrees to the direction of travel but still in complete control (as complete as anyone is on that sort of slippery stuff anyhow!) and travelling across the slope at that 45 degree angle! Looks very impressive but isn't the slightest bit worrying from inside, cos you can feel that the car has full traction and drive, you are just countering the side slope with the angle of the car!

I find that the 'better' you drive, the higher quality of control and pedal management that you can put in, the better the whole thing works with a Detroit! You get better quickly too, 'cos the thing feels right when it's being done right, doesn't feel right when you are doing things that aren't considered 'exhibiting good driving skills!' The people who seem to have the most trouble are those who continue to push their bad habits (like fishies and donuts) despite recognising that they could do better and get a better result! Changing aggressively from drive to coast and back again half way thru a 'U' turn is something that you only need to do once to realise it works better if you stay either with the power very gently ON throughout the turn, or coast all the way around - don't change, and if you hafto, do it very smoothly and gently. Aggressive accellerator movements during a 'U' turn will produce lurches, but they are so easy to avoid!

Detroits are what differentials were MEANT to be!"

Hi fellas just in response to the lockrite lokkas or early detroit lokkas, i have a fourby with a lokka in it and it is noisey as hell when engaging and disengaging, they clunk, ping and sound like something has broken they can be savage wen engaging and disengaging and i wouldn't recomend the old style i would probly go a new detroit, other then that to put a lokka in, find yourself a for nine inch and modify it to suit or just chage the tubes over in the pumpkin and get a air lokka from ARB to siut a ford bronco with a nine inch diff centre.

i live in WA... no rain
i have the power to lock the wheels on the spot, so for me bitumen/gravel/rain - its all the same if i floor it around a corner

the kickout isnt harsh, its more a "float" out sideways with a gentle return, almost identical to the Phoon

The best fun is 3:77 diff gears with a mini spool in the wet in my ef sedan, dounuts and driffting r fun.

Seems okay. Can you compare this to the diff you had before?

I tend not to wheel spin these days unless there's ice or i'm off road, but due to the inside-wheel-drive thing a locker may cut in a bit on gravel roads. Sometimes i drift due to high cornering velocities, but maybe the diff type won't matter much to this.

It's sure been a challenge to nut-through the lowdown on auto-lockers. A lot of research and a little progress thus far.

I'm thinking the vehicle and driving style play a major role in whether they a good option or not, as well as finances and noise tolerance, etc. A situation that may be suitable for auto-lockers seems to involve a long wheelbase, a low centre of gravity, well controlled suspension (design, bushes, shocks, etc), and a preference for smooth driving.

Last edited by relaxed_diplomacy on Sun Dec 30, 2007 10:56 pm, edited 1 time in total.

How many ticks do i get . . . short wheel base, leaf springs, worn suspension bushes, worn shocks, high profile tyres, young driver?


Can you explain this for me, especially about the "tubes"?

no worries i'll explain it for ya mate, mini spools r fun to start off with but i don't recomend them to anyone, i would actually talk you out of it, cause
1. your axles r always locked and it ain't good for them, they stress to the point that they can break.
2. your tyres will wear funny and the tread will start feathering with hi and low spots all over.
3. the two above r caused by the inside tyre trying to spin as fast as the out side tyre but also trying to grip at the same time.

The lokka is fun short or long wheel base doesn't really matter, the noisy operation of it you get use to it and don't really know u it's there after a while, high or low centre of gravity not a big part unless you in a fourby that is skyjacked to the max then u have to be carefull, (like mine truck) bushes! would be better if they wern't flogged out along with the shockies, agressive driving plays a big part on the lokka diffs, if u drive normally they will stay disengaged and act like a normal diff does, drive agressively and it will stay engaged also if you have big tyres they tend to keep the lokka engaged to, and as oppposed to a young driver i can't talk cause i'm still young and give mine heaps, so it is always engaged and wearing tyres.

TUBES. this would be the easiest way i could think of fitting a lokka to ya falcon and that is try and find yourself a ford nine inch diff, prefferably and leaf spring type, depending on the width it might just bolt straight in, but if it doesn't you could use your diff housing or go to the wreckers and buy a blank housing out of your model falcon, and all you r u really need to do is pull the tubes out of ya falcon housing and pull your tubes out of the nine inch housing and put your falcon tubes into the nine inch housing so the 1. it will bolt up the same. and 2. u put your axles back in and all that u need is a 28 spline air lokka to siut your axles, which should b 28 spline, hey presto lokka in falcon that can be engaged wen ever u want or need it. hope this helps you out a lot.