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Can an LSD wear out to a point where it acts like an open diff?


mel.d
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I know it's a weird question, but my 02 LE has the orange LSD sticker on the rear diff. However, when I had my truck on jack stands, I was rotating one side of the wheel in the forward direction and the other side of the wheel was turning in the opposite direction while in neutral. This indicated that this was an open diff.

 

So is it possible that an LSD can wear out to the point where it becomes an open diff? I have 130k on my truck. I purchased it at 100k and immediately changed the rear diff with Mobil 1 gear oil. I have done a second change at 120k.

 

Thoughts?

Edited by mel.d
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I know it's a weird question, but my 02 LE has the orange LSD sticker on the rear diff. However, when I had my truck on jack stands, I was rotating one side of the wheel in the forward direction and the other side of the wheel was turning in the opposite direction while in neutral. This indicated that this was an open diff.

 

So is it possible that an LSD can wear out to the point where it becomes an open diff? I have 130k on my truck. I purchased it at 100k and immediately changed the rear diff with Mobil 1 gear oil. I have done a second change at 120k.

 

Thoughts?

If its a late c200 axle like in my r20 model then yes it will be shot, as the later ones are made of @!*% steel

And the diaphragm springs crack, but stay in place albeit with no

Pressure on LSD clutches

 

If its an h233b then not likely as uk r20 to '99 had this axle as well as patrols/safaris and loads of pathys and this axle (and if it is an LSD variant) is bomb proof

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If you don't use the correct gear oil (with the friction-modifying LSD additives) then the effectiveness of the LSD clutches will be reduced. Nevertheless, the stock LSD isn't very effective anyway.

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It depends on the type of LSD. I don't know (since I don't have one) what type of LSD comes with the Pathys.

 

A Torsen diff, as an example, without any torque applied will act like an open diff so jacking up the rear and spinning one wheel by hand will not be a good test. If it's a clutch based LSD the TBR factor determines at what point the torque is transfered to the other wheel. A mechanical LSD does keep both wheels spinning.

 

Try doing a burn out or you may try holding one wheel while having a lovely assistant rotate the other wheel, which should generate some torque and thus the power should transfer.

 

Also, as XPLORx4 said the specific oil is important for LSD and yes after 100k+ miles the effectiveness of the factory clutches could be questionable.

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lsd in mine has 230k on it i did a burnout the other and donuts and friction modifier wont that make it slip more instead of grab u do need is but a lil less over years can give some more bite to a diff and make it lock more but will also give it more chatter at least it did with the clutch type lsd in my old supra but if there a torsion then throw everything i said out the window

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I'm certain it is a clutch type LSD. I've used Mobil 1 gear oil in the correct weight. It is a synthetic and according to the bottle, is compatible with LSD rear differentials.

 

At this point, I'll assume its just a worn out LSD. I was hoping that it was an open diff because it would make upgrading to a rear locker so much simpler.

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As I said the test you performed is not accurate even though it's thrown around on the Internet a lot. In most cases there has to be some torque generated for the LSD to function. Also, the Torque Bias Ratio built into the clutch packs determine at what point the torque will be transferred, you can add and remove plates to change the bias from 4:1 for e.g. to 2:1 etc. The clutch packs can also be replaced with new ones. Talk to a couple of differential shops in the area to get an estimate. I wouldn't discount an LSD that easily I know this because in the racing world a properly setup LSD is king (not a selectable locker).

Edited by stioc
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If you don't use the correct gear oil (with the friction-modifying LSD additives) then the effectiveness of the LSD clutches will be reduced. Nevertheless, the stock LSD isn't very effective anyway.

Pretty sure this isn't true. Friction modifier is used to make the LSD action more transparent to the driver (less chatter), not to improve traction. It should actually make it slip more easily.

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Why is that?

It is my understanding that an open diff is easier to upgrade to a locker than a diff with an LSD.

 

 

 

As I said the test you performed is not accurate even though it's thrown around on the Internet a lot. In most cases there has to be some torque generated for the LSD to function. Also, the Torque Bias Ratio built into the clutch packs determine at what point the torque will be transferred, you can add and remove plates to change the bias from 4:1 for e.g. to 2:1 etc. The clutch packs can also be replaced with new ones. Talk to a couple of differential shops in the area to get an estimate. I wouldn't discount an LSD that easily I know this because in the racing world a properly setup LSD is king (not a selectable locker).

 

Got it. I'll perform the same test but add some resistance to the opposite wheel to see if the LSD engages. If it is worn, I don't think I would bother rebuilding or adding any plates but rather look into a locker instead.

 

Over the weekend, a cousin and I replaced the clutch on his 350Z. While it was on jack stands, I spun one wheel and the opposite wheel rotated in the same direction. Essentially it was the same test that I did on my Pathfinder, so clearly he has an LSD. That is what got me thinking that mine was either worn or does not exist.

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Pretty sure this isn't true. Friction modifier is used to make the LSD action more transparent to the driver (less chatter), not to improve traction. It should actually make it slip more easily.

That was my understanding as well. If your LSD is chattering, then it needs the friction modifier to reduce friction; ie LSD engagement. So if I change my rear diff oil to regular diff oil, then wouldn't the LSD engage more frequently leading to the chatter?

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Pretty sure this isn't true. Friction modifier is used to make the LSD action more transparent to the driver (less chatter), not to improve traction. It should actually make it slip more easily.

 

Hmmm, ok my misunderstanding then. In any case, I never found the stock LSD to perform particularly well for off-roading. Hang a front and rear tire in the air, and you go nowhere.

 

It is my understanding that an open diff is easier to upgrade to a locker than a diff with an LSD.

 

That depends on the locker. I may be wrong, but I believe the only locker available for the H233B 33-spline is the ARB air locker, which replaces the whole carrier, so it doesn't matter if you have an open diff or LSD to start with.

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Hmmm, ok my misunderstanding then. In any case, I never found the stock LSD to perform particularly well for off-roading. Hang a front and rear tire in the air, and you go nowhere.

Not at all sure on this (not really an off roader) but my impression was that you could resolve that by light application of the brakes.

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Not at all sure on this (not really an off roader) but my impression was that you could resolve that by light application of the brakes.

 

Nah, that never worked for me. I had considered at one time trying to figure out a way to apply the parking brake individually to each rear wheel, but alas it was just simpler to get an ARB locker.

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Related question...assuming an LSD is functioning properly...should it be limiting slip in reverse as well as forward? I would think yes...but the lsd in my 97se does nothing when i back out my driveway which is uphill to the street. Drivers side tire doesnt spin at all while other side is a pinwheel...

 

So mine may be shot after some 150k miles or so.

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