too meeee they look look like springs out of a motorbike clutch.

how does it work?
is it like a detroit locker?

Just do a search on this site and type in "phantom grip" and that should provide some background on the operation of these things and the previous questions as to how effective they are

pro-240c
I'm guessing that you have never seen a Detroit locker, & you don't know how they work.

A Detroit locker does NOT incorporate a differential in it's conctruction. It still uses the crownwheel & pinion but the diferential component is replaced with a mechanism that drives both axles untill one axle speeds up. In this case, this faster axle over-rides the dog clutch mechanism & free wheels.

Heres the picture.
In the straight ahead position, both axles are driven by dog clutches & positive "locked" drive is achieved. If one wheel is in the soup & would normally have slipped, the other wheel still drives as the axles are locked together.
If you turn a corner, the outside wheel speeds up & this allows the drive mechanism for this axle to ride up over a cam arrangement, releasing the dog clutch. This wheel is NOT receiving drive from the unit, it is instead, frewheeling. If one is doing circles in a roundabout, the drive plate will run completely over the cam & drop the dog back into engagement momentatily before lifting it out again. This is the loud metalic "click" that these units make.
At this time, the vehicle is being driven by only one wheel, that being the inside rear in a rear drive application. If the tyre should slip, the wheel will speed up [due to the slippage] As the drive axle speed catches up with the freewheeling one, they lock together providing locked drive.

I had one of these in a Falcon Van for evaluation purposes & believe me, for normal road use, they are vile hatefull things.

Problems....
When applying power in a long sweeper, only the imside wheel is driving, so plenty of additional lock is needed to counter the forces from asymetric thrust which is trying to push the car straight. This is murder on the front tyres. A very "steady" driving style minimises this

We found that If you have the pedal down in a sweeper, then don't even begin to think of upshifting to another gear in the turn because depressing the clutch removes ALL asymetric thrust. It's only then that you realise just how much extra lock you have dialed in to compensate. The vehicle can have a savage tendancy to swap lanes.[to the inside] Reducing power to remove asymetric thrust first, allowed satisfactory gearchanging.

All take offs are best done in the straight ahead position. If you have some lock on, only one wheel is driving, & can start off with some wheel slipage. This is not good for tyre wear. If you are heavy enough on the pedal, the sliping wheel catches up with the other axle, & both axles engage with a BANG. This locking of axles tries to drive the car straight, but you are turning, remember.

On wet or slipery roads, it's quite possible to spin up both wheels, say in a roundabout. When this happens the car has NO LATERAL SUPPORT whatsoever at the rear & the tail comes straight around. This action is IMMEDIATE, if not actually instantaneous, & irreversable. It is possible to swap ends in little more than the length of your own car.

I have done just about every stupid thing that it is possible to do with one of these, but under supervised & controlled conditions on the Police driver training school in the ACT. Additional testing was done by me on public roads, & in the scrub.
The conclusion that we reached, officially, was that in the right hands, it could provide up to 80% of the performance of a true 4wd, but that, in the hands of the "average" driver, it was death on wheels, & we did not adopt it.

We also found on test that the "average" driver over-estimates his ability by a very substantial margin. The more that they told us how good they were, the greater the gap between "boasted" ability, & "actual" ability. Drivers over 50 generally gave the best results. [I was in my late 30's]

From some of the posts i have read, i would not entrust a shopping trolley to some people,... & i sure as hell don't want to be on the same road if they are driving a performance car with a Detroit locker.

Good Points.
Absolutely unsurpassable for drag racing where a "diferential" action is also a requirement, otherwise, get a spool.

Great for use in the rear axle of some serious off roading 4x4's

Suitable in some applications where towing is involved, or in some rural applications.

Conclusion.
Unless you have a genuine use for one, you are only buying trouble.

I finally got my coupe back together on the weekend so I had the chance to test the spring loaded locker I made.

I have been wondering for a long time if these things work or not even after some members said they work. Mick you were right.

Well they do work or at least the one I made works.

They are A SPRING LOADED LOCKER and act exactly like the name says. They lock and unlock depending on the load applied to the centre drive pin inside the standard open diff.

The cars handling still behaves a bit like the car runs a locked diff but it has lessened the "understeer on the way into corners/ oversteer on the way out" characteristics.

I have only tested it briefly in very wet muddy conditions and wont know the full effects until I get the car in stage and drive it hard.

This set up is better than a fully locked diff and better than an open diff but not as progressive as a real LSD.

For the price they are not too bad and I learnt a lot making it all work.

Paul.

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which is all i wanted it for.
thanks for the essay....

who said sh1t about track racing? i certainly didn't...

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actually i do know how they work.
which is why i want one.

the phantom grip may be good or okay for circuit racing - but i don't want it for that.

my 240C is only good for drag racing. i shudder to think how it would perform on the track....understeer into a corner, oversteer on the way out - open diff or not.

good to hear someone else thinks these things work!, you really think you get more understeer though? ive never noticed it, in fact i have positive camber on my car and still dont get understeer, maybe i just drive around it?

I dont "think" they work I now "know" they work. From my experience testing on the weekend the diff was locking and unlocking even under reasonably light throttle loads because it was really muddy.
Re understeer - I am not saying that I have more understeer than with a fully locked diff but understeer is still evident in the mud with the spring loaded locker. I am really interested to see how it goes in the dry once I start pushing my coupe along a bit. Only then will I be able to start tuning the rest of the suspension to suit the new handling characteristics but it is encouraging that they do lock and unlock without throwing the car off balance.

I must admit that I was one of the non believers but I have to say that I was wrong about that. Will have to wait and see how long everything lasts and how quick the plates wear out.

1200coupe, any updates on your posi locker? Actually anyone interested in making one up for me for a h165 diff...4.11 and 4.875 ratios?

Or anyone want to email me or even sell me some plansso that I can get my local machinist to make one up? Please!!!!

bump BTW 1200RC where did you get your one from? Was it a phantom grip?

mine was not phantom it was through a mechanic down here

though,

i have just completed making one for a sprinter diff (bro in law gave me drawings to make one upto so i did it for that) I am waiting to see how that goes, if that all goes well i will be knocking out a bunch for h165 and h190, possible 145 if theres intrest? (and sprinters)

and you can expect them to be much less than the $250 i paid for mine

RC you can put me down for at least 2

thanks for the intrest, i'll let you guys know when i'm ready to knock up a bunch to get exact numbers, hopefully within a few weeks

what diff is under a 1000 wagon? H145?
if so, count me in !!!

This is an update on the

let us know how you made it, my bro-in-law is looking into making one

what springs did you use and how did you work out which to use basically

1200rallycar,

I made it out of a material I know as TOH or tooling plate. Heat treated and tempered back until it's hardness is less than the sun gears inside the diff centre. I wanted the plates to wear instead of the faces of the sun gears.
I found that it is important to face all the diff gears first so they are flat, then measure the distances inside the centre. The closer the tollerances on the fit the better the locker will work. This part is critical because someone here in Canberra already has a bought one in their rally car and they have been finding that it locks ok but has been jaming and not unlocking properly on dirt. I suspect this is due to the clearances between the centre pin drive slot and the sun gear faces is too large. I know the plates are spring backed but the clearances definately effect the way it operates/locks/unlocks etc.

Another thing to consider - I have three H165 centres and they are all different, some have very little sun gear face surface area and another has a lot of material on the faces. The one with lots of sun gear surface area is the one to pick because it means that thepreload force can be applied over a larger surface area.

I cant give you the spring details other than to say that it talks 140kilo's to press the two plates together once the four springs are in place. I hope to measure the pre load sometime next week once I have made an axle spline fitting to suit my torque wrench.

It would take too long to go into manufacturing detail in a post so PM me when yourr bro in law is ready to start and I will give you my contact numbers.

Paul.

they look like valve springs to me....!

great concept there. top job

okay, after my search on phantom grip there seems to be a lot of controversy regarding how they work and -if- they do work. it seems spring pressure is the main issue here, needing a nice solid spring to make it work properly.
methinks this will work in something more like a bluebird/200B borg warner, a 9inch, a hilux diff or the later type of H165 with larger gear faces than the earlier types.

these springs shown look an awful lot like L series valve springs to me, and if about 140kg of pressure is required for all four to be compressed, then i think i'm about right.

why, if spring pressure and strength is the issue, would you not machine them to take chevy double valve springs...? it would take a good 270odd kg of pressure - pretty much double - to compress all four at once.

with the larger gear faces and twice the spring pressure, would this not NOW make it an effective phantom grip?

pro-240c,
Yes there is some question as to how effective these things are, thats part of the reasoning behind making one and testing it, although 1200rallycar has a production one fitted to his car and he said that his worked.
The springs are not valve springs. If you look at the top righthand side of the photo above you can make out some of the spring dimensions noted there. Thats part of the reason I took the photo that way - so people could see some of the spring specs, I havent mentioned the spring gauge but you can estimate from the photo if you have too.
I dont imagine valve springs would fit because they are too big in lenght to go inside the plates, this whole assembly is quite small in size. Also the idea is to not have tooooo much spring pressure or the thing will act just like it is locked all the time and welding the diff is a much better way to go if this is what you want to achieve. Keep in mind that my application will be rallying on a loose surface so the limiting factor is the grip level on dirt, hence my concern that the preload applied by the springs might be to much. I have done some rough calcs and if I'm right the preload will be around 40ft/lbs.
Out of interest, the pre load specs on a subaru front LSD (ARC Group N rally car) is between about 30 - 45ft/lbs, keeping in mind that they are a far heavier car than my coupe. Of course there is a bit of trial and error in all this but I dont mind sorting this sort of thing out. I'll know as soon as I get the car back out in the forrest but I imagine if the spring loaded locker works then I will be back to changing the front suspension geometry to reballance the car on dirt.

it's certainly an interesting concept.
and not one to be dismissed so easily, considering the pre-load values are similar to WRCars with a 120Y budget.

kudos

The subaru spring preload acts on clutch discs and is only a servo mechanism for the spider supports. The spider supports spread the hemispheres to provide the locking action.

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Exactly right feral. For those that dont know, the springs in the subi centre we are speaking about are not springs as in the photo above but they are Belvadeer washers. They are like a normal hardened large flat washer but are cup shaped so when they go inside the centre they tend to squash flat. It is the action of the washers wanting to return to their cup shape and the resultant force that provides the diff preload.Then its the spider supports that spread the hemispheres to provide the locking action. Different preloads in these centres is achieved by changing the Belvadeer washers.