stupid question about lockers but answer needed please

[muskie]

my terrano rear diff has an arb locker fitted, now the bit i cant get my head round before locker was fitted it was an lsd, i am now assuming it isnt lsd, am i right? i didnt fit it so am unsure about the inner workings.. be gentle with the answer

[Jerry]

most terrano's have factory LSD's, LSD works up to 80% of the time to lock the diffs, ARB locks it 100%. the LSD part will have been removed when the ARB went in

[kiwipete]

Id like to get my hands on your old LSD bits, mines an open diff.

[cool__bananas]

now your diff is either fully open or fully locked, where as a lsd is always 80% locked and can still a bit like a open, now it will be better on and off road

[muskie]

Id like to get my hands on your old LSD bits, mines an open diff.

sorry pete the truck came with locker fitted and without other internals, otherwise i would have given you the parts. my other 1994 terrano has LSD aswell, a little sticker on rear diff housing, same as on my 92, just luck they both had it i suppose.


thanks for answers

[skid]

I'm not sure about nissan stuff, but a lot of the toyota stuff you will find the LSD is a stronger diff (4 spider as opposed to 2 spider), so they probably removed the slippery parts and used the rest to keep the stronger head.

but don't quote me, coz I don't even come close to being a mechanics arse

cheers

SKID

[DieselBoy]

LSD works up to 80% of the time to lock the diffs

Bwahahahaha, is that right Jerry????

This is a question that comes up time and time again. Perhaps search????

An LSD is not a locker. It does not EVER lock the diff. All it does is supply fractionally more torque to the wheel with traction than you would get if the diff was open. They are designed for use on say an icy road, where that tiny amount of torque being transmitted to the wheel with the most traction may just be enough to alow you to move forward very very slowly. So basically they are useless unless modified.

Your ARB set up means that you have a basic open diff untill you hit the switch, and then you have a 100% locked diff, which does not allow any differenciation between the wheels.

An ARB locker replaces the whole carrier, so it doesn't make any difference weather the original carrier was two or four spider, it replaces the whole lot.

Hope that helps yo

[skid]

An ARB locker replaces the whole carrier, so it doesn't make any difference weather the original carrier was two or four spider, it replaces the whole lot.

Hope that helps yo

told ya i wasn't even a mechanics arse

[lneil]

told ya i wasn't even a mechanics arse

Now Skid, don't be hard on yourself. I'm sure I heard someone say that you were one!

(No offense, )

[tweake]

An LSD is not a locker. It does not EVER lock the diff. All it does is supply fractionally more torque to the wheel with traction than you would get if the diff was open. They are designed for use on say an icy road, where that tiny amount of torque being transmitted to the wheel with the most traction may just be enough to alow you to move forward very very slowly. So basically they are useless unless modified.

got to disagree a little there.

my LSD locks up resonable well, you can dig the ground up fairly well with the rears. unfortunatly the sudden lock up can cause the rear end to shoot sideways which can make driving interesting

however most LSD wear resonable fast and often do not lock up tight and therefore useless. also the lockup is not always predicatable, if i do not have much load on the vechile it can sit there spinning one wheel.

[scs]

depends whether mechanical opr viscous lsd, toyota ones are av cause they're viscous and they wear and get less effective with heat. i believe nissan is mechanical and are more effective.

[DieselBoy]

An LSD is not a locker. It does not EVER lock the diff. All it does is supply fractionally more torque to the wheel with traction than you would get if the diff was open. They are designed for use on say an icy road, where that tiny amount of torque being transmitted to the wheel with the most traction may just be enough to alow you to move forward very very slowly. So basically they are useless unless modified.

got to disagree a little there.

my LSD locks up resonable well, you can dig the ground up fairly well with the rears. unfortunatly the sudden lock up can cause the rear end to shoot sideways which can make driving interesting

however most LSD wear resonable fast and often do not lock up tight and therefore useless. also the lockup is not always predicatable, if i do not have much load on the vechile it can sit there spinning one wheel.

With a statement like that, you have a lot to learn my friend

An LSD is not a locker, why do you think they invented lockers?? They wouldn't have bothered if an LSD did the same thing.

Don't get confused and think that because both rear wheels are spinning together that the diff must be locked. If both rear wheels are getting even traction on what ever surface your on, they will both spin. If one wheel is getting less than the other, the wheel with the least traction will spin and the other will stand still.

Here's some home work for ya:

http://en.wikipedia.org/wiki/Limited_slip_differential

http://auto.howstuffworks.com/differential4.htm

[Jafa]

Yip, what he say, Dieselboy is correct

[tweake]

An LSD is not a locker. It does not EVER lock the diff. All it does is supply fractionally more torque to the wheel with traction than you would get if the diff was open. They are designed for use on say an icy road, where that tiny amount of torque being transmitted to the wheel with the most traction may just be enough to alow you to move forward very very slowly. So basically they are useless unless modified.

got to disagree a little there.

my LSD locks up resonable well, you can dig the ground up fairly well with the rears. unfortunatly the sudden lock up can cause the rear end to shoot sideways which can make driving interesting

however most LSD wear resonable fast and often do not lock up tight and therefore useless. also the lockup is not always predicatable, if i do not have much load on the vechile it can sit there spinning one wheel.

With a statement like that, you have a lot to learn my friend

An LSD is not a locker, why do you think they invented lockers?? They wouldn't have bothered if an LSD did the same thing.

Don't get confused and think that because both rear wheels are spinning together that the diff must be locked. If both rear wheels are getting even traction on what ever surface your on, they will both spin. If one wheel is getting less than the other, the wheel with the least traction will spin and the other will stand still.

Here's some home work for ya:

http://en.wikipedia.org/wiki/Limited_slip_differential

http://auto.howstuffworks.com/differential4.htm

i never said an LSD was a locker.

i certainly get both wheels driving at even rate after lsd cut in when one wheel is on the hard and the other is on the slippery stuff. the amount of slip between the two wheels is practicall zero.

[Sadam_Husain]

i never said an LSD was a locker.

i certainly get both wheels driving at even rate after lsd cut in when one wheel is on the hard and the other is on the slippery stuff. the amount of slip between the two wheels is practicall zero.

I think you covered yourself ok in that first post tweake, but I know my old Cruiser LSD might as well have been an open diff coz thats how good it was (or wasnt)

My LSD locks up resonable well, you can dig the ground up fairly well with the rears. unfortunatly the sudden lock up can cause the rear end to shoot sideways which can make driving interesting

however most LSD wear resonable fast and often do not lock up tight and therefore useless.

[DieselBoy]

i never said an LSD was a locker.

i certainly get both wheels driving at even rate after lsd cut in when one wheel is on the hard and the other is on the slippery stuff. the amount of slip between the two wheels is practicall zero.

I think you covered yourself ok in that first post tweake, but I know my old Cruiser LSD might as well have been an open diff coz thats how good it was (or wasnt)

My LSD locks up resonable well, you can dig the ground up fairly well with the rears. unfortunatly the sudden lock up can cause the rear end to shoot sideways which can make driving interesting

however most LSD wear resonable fast and often do not lock up tight and therefore useless.

Lmfao, did anybody bother to read the the links????

An LSD does not lock up EVER. They are not designed to. Read the links i posted. Its simple stuff.

If all of a sudden both wheels start spinning together, that inicates the wheels are now getting even traction, not that the a LSD has locked up.

Very simply an LSD is a basic open diff with a couple of clutch packs in it to increase the torque required before one wheel will spin and the other will stand still.

Thats all.

It is not a locker.

It does not lock the diff

I suggest everyone do some serious research before posting anymore in this thread, read the info in the links i posted, all factory clutch type LSD diffs are of largly the same construction and work based on the same principle. Once you get your head around whats inside an LSD, maybe you will understand how it works


EDIT: Corrected a rash statement

[tweake]

If all of a sudden both wheels start spinning together, that inicates the wheels are now getting even traction, not that the a LSD has locked up.

Very simply an LSD is a basic open diff with a couple of clutch packs in it to increase the torque required before one wheel will spin and the other will stand still.

they can't have even traction, eg one wheels has been spinning on the mud and the other is on metal road. they certainly cannot get even traction. no problem driving off it, watched the wheel on the grass spin then lsd grabs and both wheels rotate together. simple.

LSD are designed to slip but that doesn't mean that in certain conditions the clutch packs won't lock up. granted if you put the boot in you can easily over power the grip of the clutch packs and it will slip. old trick was to use some of the racing oils in the diff, its not meant to be used on street vehicles as it makes the clutch pack not slip as much, they tend to grab (risk damaging the clutch packs). i think it was some of the toyo guys that used that because of the toyo LSD slips way to much to be of use.

lockers are far superior simply because they are on/off unlike LSD which gives variable amount of slip (0-100%). also the locker is on when you want it, LSD is somewhat unpredictable in how/when it operates and LSD disconnect (or slip more) when off the gas ie going down hill so you can loose engine braking to one of the wheels.

[darinz]

Dieselboy,
Before you start making rash statements like "all factory LSD's are the same construction" I suggest you check your facts. Even with Nissans there are 2 types of LSD ie mechnical and viscious type.
And if you bothered to read what people were saying you would see that they are not saying the diff centre is locked, they are saying that they get drive to both wheels. And reguardless what you think, this does happen.
With an LSD that is working properly you can get traction/wheelspin when you have greatly different surfaces. I use to test mine with one wheel on grass and the other on gravel. If both didn't spin on take off then I would change the oil and then they would. There is a lot you can do to make an LSD work better. The first 3 years of winch comps I competed in I had an LSD in the rear and a locker in the front. A car I use to have would slide the inside tyre when turning a tight corner and it even did that when you push pushing it, and that was an unmodified LSD.
Do they lock the diff centre and provide 100% traction at any time? Of course not, and no one has said they done? (so technically you are correct here)

I suggest you listen to other people experience, then add that to what you have read on the internet and then you may learn something useful. Something you will learn when on these forums is that there is always someone out there who knows more than you, so pull you head in a bit and respect other people opinions.
That is what this is all about, share your knowledge and experience without and listen to others. If someone is wrong then inform them but if you are going to make statements like you just have then you had better be very sure of yourself!

[DaveM]

Its soooo funny how many threads turn into "I'm right, you are wrong" debates, instead of doing what darinz suggets

My old GQ lsd was tight enough for the tyres to chirp when turning sharply on tarseal, and you could feel it lock for a split second (well thats how it felt anyway)

[DieselBoy]

Dieselboy,
Before you start making rash statements like "all factory LSD's are the same construction" I suggest you check your facts. Even with Nissans there are 2 types of LSD ie mechnical and viscious type.
And if you bothered to read what people were saying you would see that they are not saying the diff centre is locked, they are saying that they get drive to both wheels. And reguardless what you think, this does happen.
With an LSD that is working properly you can get traction/wheelspin when you have greatly different surfaces. I use to test mine with one wheel on grass and the other on gravel. If both didn't spin on take off then I would change the oil and then they would. There is a lot you can do to make an LSD work better. The first 3 years of winch comps I competed in I had an LSD in the rear and a locker in the front. A car I use to have would slide the inside tyre when turning a tight corner and it even did that when you push pushing it, and that was an unmodified LSD.
Do they lock the diff centre and provide 100% traction at any time? Of course not, and no one has said they done? (so technically you are correct here)

I suggest you listen to other people experience, then add that to what you have read on the internet and then you may learn something useful. Something you will learn when on these forums is that there is always someone out there who knows more than you, so pull you head in a bit and respect other people opinions.
That is what this is all about, share your knowledge and experience without and listen to others. If someone is wrong then inform them but if you are going to make statements like you just have then you had better be very sure of yourself!

I am most certainly very sure of myself on this topic my friend. Don't take my posts the wrong way anyone, i am mearly trying to educate.

Read the post on attack the subject not the person I will tone it down fo ya

Anyways, back on topic.........

The debate seems to largly surround whether or not an LSD locks up or not.

Lets take the Clutch pack Lsd commonkly found in the rear of most 4x4's such as safari's cruiser's, hilux's and Terrano's as an example

So to you guys that reckon your LSD locks up like a diff lock, please explain. I have posted my side of the argument stating why i believe they don't lock up like a locker, but you guys have yet to produce any Technical info that supports your beliefs/opinions.

Please explain to me how a clutch pack in a diff head that supplies a small amount of constant friction (ie does not vary) to the side gears makes the diff lock up as load increases.

My side of the case is basically that due to the constant and unvarying pressure applied by the clutch packs to the side gears (or carrier internals depending on how they are constructed), that as the torque is suplied to the wheels, in a situation where there is a varience in traction between the wheels on the same axle, the torque will be enough to over come the clamping pressure of the clutch packs and allow one wheel to spin and the other wheel to remain stationary, not lock up as you guys reckon.

If you are going to convince me and a whole bunch of other people that are no doubt reading this thread with interest that an LSD diff locks up under load, please put forward a technical explaination of how his occurs/ works.

From there we can move onto the Visous type LSD's.

This is gonna be the most awesome Tech thread if we keep it civilised!!!!!!

Right, serve it guys...........

[DieselBoy]

We also need to clarify the deffinition of "locked"

For the sake of this debate, i have taking the term locked to mean:

"differentiation between the wheels can no longer occur"

Which is different to:

"the wheels are spinning at the same speed" - as that can also mean that the wheels are getting even traction.

[skid]

We also need to clarify the deffinition of "locked"

For the sake of this debate, i have taking the term locked to mean:

"differentiation between the wheels can no longer occur"

Which is different to:

"the wheels are spinning at the same speed" - as that can also mean that the wheels are getting even traction.

skids 2c worth

my old 40 had a slippery rear and it could easily light up both rear wheels on the coarse chip metal road

drifting is soooooo cool in a 40

but I'm not saying it was locked, I'm only saying that 2 wheels were spinning up hard.

so there

[DieselBoy]

We also need to clarify the deffinition of "locked"

For the sake of this debate, i have taking the term locked to mean:

"differentiation between the wheels can no longer occur"

Which is different to:

"the wheels are spinning at the same speed" - as that can also mean that the wheels are getting even traction.

skids 2c worth

my old 40 had a slippery rear and it could easily light up both rear wheels on the coarse chip metal road

drifting is soooooo cool in a 40

but I'm not saying it was locked, I'm only saying that 2 wheels were spinning up hard.

so there

Yep, as both rear wheels where getting a relatively even amount of traction, same as on grass, or mud, or rock or tar seal, when ever the wheels are getting an even or roughly even amount of traction they will rotate together in both an open or LSD diff. This does not mean they are locked though, differentiation will occur again as soon as there is a difference in traction, i.e, on wet muddy grass with minimal tration, but that traction being relatively even to both wheels, and say one wheel hits the concrete driveway, the wheel on the grass will keep spining at the same rate and the wheel on the concrete will come to an abrupt stop. With an open diff, thats about as far as you would probably get (Ok, more rev's, momentum, but for the purpose of this argument..... ). With an LSD, there would still be a small amount (very small) amount of torque being applied to the wheel on the concrete, and it may or may not be just enough to alow the vehicle to creep forward.

[Sadam_Husain]

Perhaps the use of the word tight may have been a better choice of words than the word locked or lock when the term LSD was being discussed in the previous posts

Your not wrong with what you say DB but I dont think any of the previous posters actualy meant to suggest an LSD is a locking diff in the definition of a locking diff, I'd say its a case of the laptop not writeing it all down how the brain wants it written down

[tweake]

i don't know much on them but from the links you provided....
http://en.wikipedia.org/wiki/Limited_slip_differential

"The clutch type LSD responds to driveshaft torque. The more driveshaft input torque present, the harder the clutches are pressed together, and thus the more closely the drive wheels are coupled to each other."
"The clutch type has a stack of thin clutch discs, half of which are coupled to one of the drive shafts, the other half of which are coupled to the spider gear carrier. The clutch stacks may be present on both drive shafts, or on only one. If on only one, the remaining drive shaft is linked to the clutched drive shaft through the spider gears. If the clutched drive shaft cannot move relative to the spider carrier, then the other drive shaft also cannot move, thus they are locked."

so it sounds like how well the clutch pack slips is determined by type of clutch material, lubracant and the amount of torque applied. just like most clutches they will grap rather than slip in the right conditions. not much different to a gearbox clutch.

put the right amount of torque on to push the clutch pack together which increases friction, get enough and the right lube the clutch will lock rather than slip.
however as its effectivly driving a wheel through a clutch pack there will be a HP limit that the clutch pack will handle. just like any clutch too much power through it will make it slip.

so if your lead footing it, the LSD will always slip. for us we are only light 4x4ing, tread softly approach so we do not put a lot of power down which dosn't force the LSD to slip.

[lneil]

Ok, I'm definitely not an authority on anything, but have spoken at length to the technical guru at Suzuki NZ about this.

I may be mis-reading you DB, but get the impression that you believe the clutch-type LSD maintains constant friction, and therefore slip/grip. I have been assured (most adamantly) that they are definitely designed for the level of slip to alter under different torque-loadings. One thing I couldn't understand was how the mechanical centre LSD works in the current model Grand Vitara. It is able to be locked by a seperate switch, but when un-locked acts in a normal LSD fashion. Too technical for the likes of me.

I have got a slipper for the rear of one of the zuk's and been advised to shim it up slightly to increase the unloaded friction level. Also to run a specific LSD diff-oil (actually a jeep product) intended to increase the efficiency of the clutch-pack and minimise fluid scorching and degradation.

Any comments from you guys with experience of running these?

[xj]

My only input is from the now aging boy racer days. the arse end in the old 302 powered XD ALWAYS lit up and dragged to the left, hence making donuts a dream (the BR version, not the Homer Simpson version). This was due to the LSD engaging. Now the wifes 350 VT, lights up in a dead straight line and the arse never wavers.... no LSD.....

Im in agreement with DB (dont fret, it will never become a habit!!!). The LSD never "locks" anything, it distributes torque when one side gets "loaded up" the torque is transferred to the opposite side.

Muskie, theres not such thing as a stupid question (well there IS, but you know what i mean!!!) but there is such a thing as retarded answers, I'm a freaking expert, I should know. For extra clarification on experts of retarded answers, peruse any of Skids 2500 responses on this forum.

[skid]

[quote="xj" For extra clarification on experts of retarded answers, peruse any of Skids 2500 responses on this forum. [/quote]


I CAN FEEL THE LUV ALL THE WAY DOWN HERE IN WELLY DUDE

[xj]

Hey, what can i say, its ALL about the love man, and there aint enough of it in the world!

[skid]

Hey, what can i say, its ALL about the love man, and there aint enough of it in the world!

oooooh, skiddy still luvs ya