Front LSD, swap from rear diff??

[EricB]

Yeah I spoke to my mechanic and he thinks an LSD in the front sounds good.

I'll keep asking around for pricing.

Thanks

[Beastmavster]

Just one of those questions I have to ask the airlocker-or-nothing guys:

Seriously guys if it was such an issue with the steering do you really think they'd install LSD's in the front of 300hp front wheel drive only rally cars that hurtle through the forest inches away from trees at 200kph?

[DieselBoy]

Its amusing some of the missguided theories of how an LSD works.

The best way to discribe it is to say that it is similar to a worn out clutch, in that as you put more an more power to the clutch, it will start to slip.

Same with the LSD, the clutch packs in a Late model Hilux diffs will handle something like 60Nm of torque before they will slip and alow one well to spin and the otherto stand still.
By shimming the clutch packs you are efectivly increasing the Torque rating of the LSD, meaning it will take more resistance on one wheel before the clutches will start slipping and that wheel stop being driven.

So there will be no loss of steering control, no sudden lock up of wheels, just slightly heavier steering with your free wheels hubs engaged.

Some one correct me if I'm wrong!!!!!!

[Beastmavster]

Multiple types of LSD around too... they have different actuation methods.

[Rainbow Warrior]

I rang a couple of diff places for prices on a front LSD

1 said $500

The other place said that you dont know when the LSD grabs and lose your steering. That is why most go for an air locker to have a control.

Does this sound right?

No completely untrue, my front LSD feels like an open diff but just a bit heavier, there's no surprises other than the improvement in performance

What you describe is what front auto lockers do, I had a lockrite in a manual steering vehicle and it was a pig, wrench the wheel out of your hands at times.
I drove another manual steer vehicle with a front detroit and it was much smoother with smaller increments as it locked and unlocked.

Taking your hand off the wheel to engage / disengage a manual locker midway up a serious stage of a hill could be hairy at times.

A front LSD also still allows the vehicle to turn in mud, none of this have to put it in 2wd to round a corner business.

[Rob B]

I think this will help.

http://www.gordon-glasgow.org/lsdtech.html

[DieselBoy]

He is in correct in this statement.

Limited-slip
The feature which distinguishes a limited-slip from a locker is its progressive action. It provides some degree of differential action even as power is applied until at some point it may lock up completely, depending on how it is set up. I have heard the terms "limited-slip" and "positraction" used interchangeably and I have heard other people claim there is a difference. No one has been able to explain the differences, if any, to me. The biggest difference seems to be that "Positraction" was a particular brand of limited-slip.
The Nissan limited-slip is a Salisbury-type unit consisting of a set of discs and clutches inside a housing that provide a friction coupling between the two axles. This same type of unit has also been used in E-type Jaguars and Cobras.

Note: at one time, another type of limited-slip unit, called a Gleason-Torsen, was available for the R200. At last report it is no longer available, which is a shame, because it had all the advantages of a limited-slip with none of the drawbacks. It was a very unusual design, using worm gears, worm wheels and spur gears to limit wheelspin while still providing full differential action. Like the Detroit Locker, it will not be discussed here.

An LSD will not lock up at some point. Any one with an LSD will teel you that. Besides, if an LSD did lock up completely at some point, why would we spend $$$ on Airlockers etc whan so many vehicles come with LSD as standard??
All an LSD does apply more pressure to thespider and side gears to prevent them from transfering drive to one wheel as early as would happen in an open diff. An LSD will work to the point where the forces on the two wheels are to different for the clutch packs to grip, and the will slip alowing one wheel to stand still and the other two sin.
Its hard to describe, but it opperates like an open diff, but with the clutch packs providing more resistance to over come before one wheel spins and the other stands still. As i said before, buy putting more clutch plates in , or more shims in it further increases the risitance needed to over come before one wheel will spin by its self.

[Beastmavster]

Torsen diffs are slightly different in that they're a purely mechanical means of achieving the result a viscous (standard clutch style) LSD would.

Torsen diffs are normally used in racing applications, since you can preset a maximumproportion of torque through them - so if you want say a maximum of 6:1 torque ratio the wheel with grip will gain up to 6 times the torque of the slipping wheel.

This can help prevent breakage especially in high power applications.

[Beastmavster]

A good point to explain LSD's to people would be

Clutch type LSD (eg most 4wd's)
http://auto.howstuffworks.com/differential8.htm

Viscous LSD (normally on FWD/AWD)
http://auto.howstuffworks.com/differential9.htm

Torsen LSD (Normally Race cars)
http://auto.howstuffworks.com/differential10.htm

Note that there are different ways to effect each type of LSD.

(except of course the Torsen LSD which is a trademarked item)

[china]

just interested, how is it on steep decents with big rocks n tight corners ?
this would be the only thing stoppn me, is it ok, just heavier or a battle? or a stupid question?

[YankeeDave]

found a wrecker in melb who has up to 10 pathfinder lsd centres for $550 each.

maybe a few of us can get together and do a deal

[DieselBoy]

just interested, how is it on steep decents with big rocks n tight corners ?
this would be the only thing stoppn me, is it ok, just heavier or a battle? or a stupid question?

On decents, well logic suggests that it would be beneficial, or at the very least un-noticeable. Tight corners, well it would not reduce your turning radious or do any of the ugly things a front locker can do, but it may make you steering heavier due to having to over come the resistance of the clutches trying to straighten the wheels, but it wouldnot make you sledge straight ahead as a locker perhaps would.
You would have to bear in mind the extent to which you would notice the effects of the LSD would depend on whether you left it standard or tinkered with it.
I'm not the best person to answer this question as i have had neither in the front, but thats just the most logical answer i can think of based on what i have seen and read.
Anyone??

Cheers,
Pete.

[blackmav]

found a wrecker in melb who has up to 10 pathfinder lsd centres for $550 each.

maybe a few of us can get together and do a deal

I could be interested if could get it for about $500 odd landed in NSW

[Rainbow Warrior]

just interested, how is it on steep decents with big rocks n tight corners ?
this would be the only thing stoppn me, is it ok, just heavier or a battle? or a stupid question?

Just a bit heavier, that's all, downhill is no different to uphill or flat as far as I can tell. Mine has been tightened a lot up too.
My turning circle is still the same, I don't need to go to 2wd to go round corners like some autolockers.

[Rainbow Warrior]

found a wrecker in melb who has up to 10 pathfinder lsd centres for $550 each.

maybe a few of us can get together and do a deal

I could be interested if could get it for about $500 odd landed in NSW

What a rip off!

I heard I guy in this thread could get them in NZ for $50 each

[YankeeDave]

if he can get them for $50 i'll take one and give him $50 cash for his effort

[V8Patrol]

Very interesting read so far, its certainly got the brain cells ticking over.....



might be time to wander off n visit my favorite wrecker

[Rainbow Warrior]

if he can get them for $50 i'll take one and give him $50 cash for his effort

Somehow I doubt he'll find too many if any at that price, even in NZ dollars

[DieselBoy]

I'll put the question to the guy at "The Diff Shop" in Chch on Monday, i was just basing my logic on the fact that if he could get me an open carrier for the Safari, which are pretty rare over here, they all have the factory LSD, then a LSD terrano/Navara carrier would be about the same as they are an extremely common vehicle over here!!!!
We will see though.
I'll ask tomorrow.

[Rainbow Warrior]

I'll put the question to the guy at "The Diff Shop" in Chch on Monday, i was just basing my logic on the fact that if he could get me an open carrier for the Safari, which are pretty rare over here, they all have the factory LSD, then a LSD terrano/Navara carrier would be about the same as they are an extremely common vehicle over here!!!!
We will see though.
I'll ask tomorrow.

The Safari/MQ carrier fits in but the mounting holes for the crown wheel need to be machined larger and offset to fit.

[DieselBoy]

checking arb's parts list,

the navara/ pathfinder rear locker is the same part number as the GQ front. Must be a straight fit LSD into GQ front then.

i was told though that should be going for a Navara april 97 to recent and pathfinder dec 95 to recent for same as gq front.

dieselboy, if you do this soon, let me know how it goes, very interested in getting this done, seeing it's cheaper and softer on the drive train

So this would be a R50 Pathfinder??

[DieselBoy]

Right, so I've found one for $50.
Its from a R50 Pathfinder, 1996.
The guy checked and he reckons its a 33 spline and 9 bolt crown.
Pretty sure i have a 31 spline carrier in the front??
What do ya make of all that??

[Beastmavster]

So when are you getting me on for $50? There's a whole bunch of guys here in Aus waiting

[DieselBoy]

I gotta make sure i know exactly what I'm looking for first!!!
Some one mentioned 95 pathfinder up wards would be the correct donnor vehicle, but it appears they are not. Unless you are able to swap side gears?

[Rainbow Warrior]

I have a Pathfinder Navara one in mine, but not shure what model it's from Red Rover may know.

[Red Rover]

From an import terrano, low kms. However if you get a second hand one remember they are know to have broken clutch packs. You find this out when you go to get it tightened. Pats had a new clutch pac k put in it cause I had it done. To be truthful, with the rear locker + limo was great. I only put the fron t locker in because I couldn't get up one hill. Now I have had the claws for a couple of years, I would have stuck with the limo, rear locker and claws

[DieselBoy]

What I'm looking for must be from a WD21 Pathfinder/Navara/Terrano.
The one i have found is a 1996 R50 Terrano LSD.
9 Bolt crown 33 spline.
Some one here told me the front diff on mine is 31 spline.
Simplest way would be to dig out my old CV's and axles and count tham my self..................................

[baggers]

So how is the progress on this going just out of curiousity?
Is it as simple as a $50 part from a wrecker and a bit of work, or more like $500 and a lot of work?

[YankeeDave]

i know $50 mark has been tossed around


but on the serious note, getting a whole new lsd centre for any car will be more than $50 unless you got some major hook ups

so imho looks more like $500-$600 for a 2nd hand lsd centre from a pathfinder that should fit with no mods. Late model that is.

[DieselBoy]

Well, i passed up on that LSD center i was talking about earlier, it was from a 96 R50 Terrano, which is late modle.
The spline count was wrong.
So I'm looking out for a WD22 LSD unit to see if thats what we need.

Note we need a 31 spline , 9bolt crown, and the R50 Terrano carrier was a 33 spline, 9bolt crown.
It got me wondering if it was a cheap replacement for the rear instead.........

Any how, i had the chance to drive a Hilux with a Detoit in the rear and an LSD up front.
Climbed nicly, but an absolute mongrel in the soft slippery stuff.
Thing is, unlike a front locker, you can't simply jump out and dissengage a free wheel hub if your having trouble steering..........