LSDs in reverse....

[tandanus]

Hi all,
Should Limited Slip Diffs lock in reverse?
Or is the slip only limited when going forward?
T.

[webby]

the DR30 LSD I had in my old Skyline locked both ways, so did the TRD 2-way in my mate's smallport AE71. So I'd assume that they're supposed to do it?
Don't see how they'd not lock in reverse anyway

[dvsfin]

it really depends on the type of LSD

[Billsy]

totally depends on the type of LSD.

Viscous, Yes
2 Way, Yes
1.5 way, partially
1 Way, No
Torsion, NFI?

[webby]

the "ways"actually refer to the amount of lsd-ing the centre'll do under acceleration/deceleration, it has nothing to do with forward or reverse.
Stand on the throttle in a car with a 2-way and it's going to spin both wheels, whether it's in 1st or reverse doesn't matter.

[dvsfin]

ummmm that's not exactly right webby, billsy is pretty damn close, but it's a bit more complicated then that lol, and a torsen will work forward or reverse

[webby]

mate, spend enough time around drifters and you learn fairly quickly how these things work. Believe who/what you want, but I'd be very suprised if even a one way didn't lock up if you stood on it in reverse.

[webby]

now that i stop and think about it, i think we're both right. I haven't had anything to do with the FWD crowd (which is the only possible application I can think of for a one way) or 1.5 way diffs, I just assumed they'd work in reverse like the 2-ways I've fiddled with
The ramps in the diff that provide LSD-ing under deceleration whilst moving forward would be the ones being acted on in reverse.
Sorry if i came off as an arrogant wanker guys

[amehel0]

a bit off topic, i dont know about arrogant but a bit abrupt but you are able to admit fault and rectify it. so good on ya for not sticking by something regardless of truth to try and protect any ego. thumbs up!

[DanTurboLancer]

the DR30 LSD I had in my old Skyline locked both ways, so did the TRD 2-way in my mate's smallport AE71. So I'd assume that they're supposed to do it?
Don't see how they'd not lock in reverse anyway

the "ways"actually refer to the amount of lsd-ing the centre'll do under acceleration/deceleration, it has nothing to do with forward or reverse.
Stand on the throttle in a car with a 2-way and it's going to spin both wheels, whether it's in 1st or reverse doesn't matter.

mate, spend enough time around drifters and you learn fairly quickly how these things work. Believe who/what you want, but I'd be very suprised if even a one way didn't lock up if you stood on it in reverse.

Webby for a guy that claims to know all about drifting and a self proclaimed expert on LSDs,
you're way off dude

totally depends on the type of LSD.

2 Way, Yes
1.5 way, partially
1 Way, No
Torsion, NFI?

DVSFIN is right this is close.


1 way has a gradual ramp, when there is a difference between the rotation speed of the two axles, load is transferred from the axle that is spinning the least, as it has the most torque load on it, that forces the spider gears pinion shaft to slide on the gradual ramp, to allow the pinion to slide up the ramp and push the side plate outwards, and therefore push the clutch plates/dog gears together to engage both wheels to spin at the same speed.
It does not have a ramp in the opposite direction

1.5 way has a gradual ramp in the forward direction, but a steep agressive ramp in the reverse direction.
So it takes less load to make the pinion push the side plates out and apply load to the clutch plates/dog gears when driving in forward, or spinning the wheels in forward direction.
However due to the steep ramp in reverse direction, it takes more load to make the pinion drive up the steeper ramp, and drive the side plates out to engage the clutch packs.
So if you Dump the clutch in reverse, it will lock the rear axles to spin the same in reverse!
However if you were on wet grass, or sand, depending on how the clutches are set, it may not be able to apply enough torque to the axles, pinion, and therefore ramp to lock it up.
And NO it will not have enough torque to ramp up the steep ramp under deceleration conditions.


Unlike the 1.5way which has a gradual ramp in the forward direction, and a steep ramp in the reverse direction,
a 2 way has a Gradual ramp in Both direction.
So in either forward, or reverse it takes little torque, and load to allow the pinion to act.
Therefore under Deceleration, it Can activate the LSD conditions.
In a straight line, No.
As there is no difference between the wheel speeds, and therefore no difference in torque loads.
But if you stab the hand brake, and get the rear end sliding, or if the clutches/springs are set right, even just turning the wheels, and allowing a difference in wheel speed between the two rear wheels, Can allow enough torque difference to engage the LSD so that you can have the rear end sliding, and stepping out in a desired direction (backing in) as you come into the corner.
So that then allows you to have already lost traction, and allows you to apply acceleration and make it easier to be spinning the wheels as you apply power.


here is a quick video where you can see the ramps in a 2 way
http://www.youtube.com/watch?v=oqcPizDUekI

And a better discription from KAAZ
http://www.youtube.com/watch?v=who5AG3M ... re=related

Now in saying that.
Can a stock open diff centre lock both wheels to spin and get sideways.
Yes.
Due to tolerances in the bearing, and gear mesh it CAN allow the diff spider gears to act as though they are locking up when the wheels are spinning and there is low load on the wheels.
That is why every time it rains i have P platers crashing their cars on the round about out the front of my house, because its the only time they can attemp to "DRIFT"
It can even spin both in Reverse if you are on the grass.
But as we all know it is not a proper LSD, and can come in and out of having both wheels spinning the same speed depending on load.
And thats where you can come unstuck.


Torsion is a full Mechanical helical gear LSD as opposed to Clutch packs and dog gear set ups.

And Eaton Truetrac is also full mechanical Gear design.
However it works the opposite to what you want in a race/rally/drift lsd,
It wants to STOP the wheels spinning, and transfers the torque to the axle with the Most traction, to reduce the wheel with the least traction from spinning...

[webby]

I never said I was an expert. The only thing I did say was that I've spent a lot of time around drifters, and what do they use? CIG lockers, minispools or 2-ways for the most part, all of which lock in reverse. So I had assumed that all LSD's locked in reverse. If you'll kindly read above your own long-winded post (which contains more "self-proclaimed expertise" than all of mine put together), you'd find that I have since admitted that I was wrong in assuming that.
Maybe make sure to get the whole story next time, BEFORE making yourself look like an idiot?

Edit:
http://www.club4ag.com/faq_and_tech_pag ... al_101.htm
http://www.ppi-ats.com/LSD/LSD_basics.html

[DanTurboLancer]

Oh sorry, I thought my "Long winded self proclaiming" was actually trying to answer the question.
Not just another young bloke that doesnt actually know what he is talking about, but gives out "Advice" willingly.

But i am a Mechanical fitter by trade, and i actually pull machinery apart modify and repair them, what would i know hey

[webby]

Mate, pull your head in. I admitted I was wrong MONTHS ago, so why dig it up?
But hey, that doesn't count for anything, right? Because I'm just a young bloke who doesn't know what he's talking about, right?

Edit: Nice selective reading skills by the way. You managed to turn a post explaining that I'd already admitted that I was mistaken into a nonexistant personal attack, good work

[DanTurboLancer]

Grab a tissue and dry your eyes princess.

[tandanus]

Sorry I asked......
No I'm not - lots of good stuff here
Thanks guys
T.

[TVM006]

Everyone loves a good fight

[TUFSIG]

Reasons why I'm not here much, case in point

[A112H]

^^ +1

[75wagon]

Reasons why I'm not here much, case in point

Actually, the whole forum hasn't had much of this at all over the last 6 months or so. It's mostly been a good place to be?

[webby]

Grab a tissue and dry your eyes princess.

Reasons why I'm not here much, case in point

Actually, the whole forum hasn't had much of this at all over the last 6 months or so. It's mostly been a good place to be?

If old mate hadn't decided to dig up the long-dead past and pick on mistakes I'd already admitted to making then we wouldn't have had any of it at all
Anyway, I'm done.

[DanTurboLancer]

Reasons why I'm not here much, case in point

Actually, the whole forum hasn't had much of this at all over the last 6 months or so. It's mostly been a good place to be?

Must be me then mate.

Im not pointing the finger at any one person, or just this site.
I have found it on a number of forum websites.
There is a shortage of people who can answer real questions.
But plenty of people that have heard or read something, and pass that on as information to others wheather it is true or not.

Then there are the members that ask a basic question, and get abused for asking that question as that is apparently common knowledge to others.
I Have found that within this website, and this includes Mods.


Webby I wasnt really having a go at you.
But you obviously didnt like me having a shot at you.
Re-read your replies. You didnt actually admit you were wrong.
But that is just petty stuff.

Anyway as was one of the reasons why I stopped being a mod and went away from this site for awhile,
if you are happier having a social network and dont want actual answers to questions then youre on the path.

[webby]

As for not liking you having a shot at me, I get enough wankers that I actually know discounting everything I say on account of my age/lack of pieces of paper, so is it any wonder that it's going to tick me off when a guy I have never met does the same over the internet?
I may not have any qualifications as such, but you don't need a trade certificate to spend time messing around building/helping build cars (hell, I know an IT guy who fabricates headers that blow Pacemakers/Genies/insert other brand name extractors here out of the water in both design and quality), and to pick up a few things along the way. Such as, I know how a 2-way works, and I know how they drive, and I automatically assumed that the rest would be the same, apart from being easier to park/do a u-bolt with. Evidently I was wrong, and I DID admit to that. My apologies if said admission came off as anything else.
Also, my apologies for carrying on like a bloody wanker. There was no need for it.

[A112H]

Also, my apologies for carrying on like a bloody wanker.

You should probably slow down or use a lubricant. Sounds like a friction issue to me.

[brendon]

haha thats gold jason