Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   JK General Discussion Forum (http://www.wranglerforum.com/f274/)
-   -   DSA Anti-Spin Differential Rear Axle (http://www.wranglerforum.com/f274/dsa-anti-spin-differential-rear-axle-177901.html)

sgtleisure 08-02-2012 06:01 PM

DSA Anti-Spin Differential Rear Axle
 
Here we go...I'm in the process of researching my 2013 Wrangler Sahara and have learned quite a bit on these threads. One of the options I am going with is the DME 3.73 Rear Axle Ratio and AHT Trailer Tow Group.

What I haven't seen or read is an opinion on the DSA Anti-Spin Differential Rear Axle. I don't have any plans for any serious off-roading, so the question is...is this option necessary for local commuting? Any thoughts?

Location: Hudson Valley, NY
Sought After Vehicle: 2013 Wrangler Sahara

WXman 08-02-2012 06:04 PM

This forum has more pro-Anti-spin axle people on it than any that I've seen. So you'll probably get a lot of "yes, get it!" responses. But most forums and myself included feel like it's a waste of money. For the price of the option, you could be well on your way to a real automatic locker that works and will not wear out over time. The factory anti-spin axle doesn't work well, adds cost, and adds complexity. I personally would avoid it but that's just my opinion. Save the money and put it toward a real traction device later if you feel you need it.

Keep in mind that the JKs have traction control that works better than the limited slip differentials ever did before.

panthermark 08-02-2012 08:31 PM

Get it...

Now, there are much better limited slips out there...as the Jeep one is a fairly poor one. But Jeep LSD is fairly inexpensive ($295 MSRP), and the best part is that it comes installed. If you are going to use it as a street vehicle, and you live up north where you will have to deal with slick roads in the winter.....and you don't feel like pulling axles (or paying someone to do it)....just get the LSD.

Now...if you are big time wrencher, that would be doing a lot of wheeling....avoid the factory LSD and get something better.

12JKUR 09-26-2012 01:45 PM

I still don't understand what anti-spin diff is or how it works (brakes, throttle, mechanical???).

WXman 09-26-2012 01:51 PM

It has clutches inside the differential gears. If it "senses" a wheel slipping, it tries to push more torque to the opposite wheel. It works just ok for a while, then as the clutches wear down it doesn't work at all. It makes rebuilding the diff. more expensive. It makes fluid changes more expensive. It adds complexity to the axle, costs you $295, and doesn't really do much at all to propel the vehicle in harsh conditions.

I'd skip the option if I were you. Automatic lockers start at $300 and go up from there, and they really WORK. I find that the standard traction control system on these new JKs is plenty for the average guy.

Rooster76 09-26-2012 05:43 PM

I'll try to get you up to speed
 
I'm not a total expert on the subject, but I think I have a good enough understanding to explain it. Please correct me if you feel anything here is incorrect.

Factory Option Anti-Spin Differential Rear= LSD= Trac-Loc (I'm not sure of the exact right spelling. I have also seen it Trac-Lok, Trak-loc, Track-Lock, or even Trash-Lock)
MY QUICK OPINION ON IT
Its not bad other than it will wear out and is rather weak from the start. I personally would see if you like the factory equiped BLD-Break Lock Differential, and/or upgrade to an Eaton Truetrac that is a better (as most aftermarket stuff is). If you like trading off after 3 years then it would probably be a good option.

TERMS
diff=differential=gears in the bulge in the middle of the axle giving power to both wheels

torque=ability for a wheel to put pushing weight on the Jeep. To produce torque you need traction and power. A spinning tire produces very little to no torque.

BLD-Break Lock Differential - Computer Traction Control System that mimics LSD

DIFFERENTIAL OPTIONS - I will go through each in more detail below
  • Open Differential - What you get without the option or the only option for Rubicons (They will have BLD -Break Lock Differential explained below)
  • LSD-Limited Slip Differential (on a JK it will work with the BLD) - Works good on road
  • Part-Time Lockers - Strictly off road use or if you get stuck
  • Full Time lockers - Strictly off road and more of a dedicated trail rig option.

OPEN DIFFERENTIAL
Both wheels on an axle are only going to get only as much torque as the wheel with least traction. So if one wheel is off the ground neither wheel would get torque.

I would watch this video starting at 1:50. It is the best visulazation your ever going to get showing how open diff's work. By the end you should see why one tire can go limp if the other side doesn't have traction. @2:50 you will see the downside of lockers and how they put stress on the axle when turning.
Around The Corner (1937) How Differential Steering Works - YouTube

BLD-Break Lock Differentials - Jeeps answer to Open Differentials spinning wheels
All wranglers have BLD - Break Lock Differentials. It is basically like a computer controlled LSD(=Limited Slip Differential). It will sense one wheel on an axle spinning much too fast to just be turning. It gives a little break to that spinning wheel to transfer torque over to the other wheel, that has more traction. So really no JK has open diff's in a driving situation because of this traction control system. It's the best your going to get with a Rubicon. It's locker does not allow for a factory LSD to be added.

Here are a couple quotes from the Jeep Blog article link below.
Chrysler Blog - Jeep Brake Traction Control Explained
Quote:

Just to get this out of the way; from the Jeep perspective, BLD is not a substitute for locking differentials. It is a means to greatly expand the off road capability of vehicles that were not purchased with or do not offer locking differentials.
A Jeep vehicle with BLD will negotiate almost any obstacle or driving situation that a similar vehicle with locking differential will. BLD does require a change in driving style and more torque to negotiate the obstacle.
further down in the article
USING BREAKS TO HELP GET TRACTION (BLD or LSD)
Quote:

In order to get the most out of BLD, the driver must adapt their driving style to characteristics of BLD. For example, when in a situation where one or more wheels loose traction and the vehicle will not continue in the desired direction, the driver should carefully and smoothly apply the throttle to allow more torque to go the wheels with traction as the brake(s) are applied.
BLD looks at individual driven axles and tries to keep the wheels turning at the same speed. BLD does not try to limit how fast the wheels turn, just that they turn at the same speed.
On this video at about 45 seconds you see BLD (with no LSD) kicking in. If it wasn't for BLD the front passenger side would be totally still. It would get the exactly the same amount of torque as the spinning side, but that wouldn't be enough to over come the friction that is holding it still.
JK Wrangler Vs. Small Sandhill - YouTube

LSD- Limited Slip Differential
LSD works with either clutch plates(like the factory Trac-Loc) or gears (like Eaton TrueTrac). It lives in the differentials. It works mechanically with friction trying to keep both tires spinning together. It requires some traction(torque) from the slipping tire to transfer to the other side wheel. Because of this you can use a bit of break (or parking break) to increase its effectiveness (this also works for BLD). They are great for road driving because they can be used at high speeds and on dry pavement. There always there working without having to flip a switch. They can be put on either axle. The factory option only comes with LSD on the rear. That's the driving axle in 2WD.

POTENTIAL PROBLEMS WITH TURNING- For the most part having LSD is a good thing. Especially on slippery hill situations. It can rarely create a couple of problems. I wouldn't worry too much about this especially with the factory LSD.
  1. Over-steer =Fish-tailing -If the wheel with greater traction gets more torque, and it also starts to slip. Then you've got a fish tail situation. It could happen for example if you were at a stop sign that was really icy and turning. Itstead of spinning and going no where, you would have the back flip out
  2. Under-steer- If the preload is too great on the LSD then the break away traction for the opposite wheel may not be met. In that case the locked up axle will want to keep you going forward. I would doubt you would run into this unless you went to an aftermarket LSD

TRAC-LOC LSD- Factory Option Anti-Spin Differential Rear
When there is little or no traction your quickly eating up your clutch plates on a Trac-Loc LSD. In the "Four Wheelers Bible: 2nd Edition" he states
Quote:

By the time a rig hits 100,000 miles, the average clutch-type LSD has turned into an open diff.(page 35)
Offroad situations with little traction, like a wheel off the ground, sand, and mud are going to drastically lower it's effective lifespan. The clutch plates can be replaced when they are no longer effective. At best, just off the dealers lot, your going to get about 25% more than the spinning tires torque transferred over.
From a JP magazine web article
Read more: Jeep Locker Overview - Jp Magazine
Quote:

Trac-Lok
Overview: The Trac-Lok is the OEM limited slip differential offered in many vehicles-from early CJs from the mid-'70s up through XJs and some TJs. It uses stacks of friction discs that hold the spider gears from differentiating until enough torque is generated by the shafts to let them spin.
Street:
You'll think you're driving an open diff. The Trac-Lok is largely unnoticeable.

Off-road:
You'll think you're driving an open diff. The Trac-Lok is largely unnoticeable. Unless it's new from the factory, don't expect anything but poor performance off-road from a Trac-Lok.

Good: It probably came in your Jeep from the factory. The unit can be rebuilt at home.

Bad: They require gear oil with a friction modifier and have wearable clutches inside. If you're planning on adding a lunchbox locker, you'll need to order a special application that will work with the clutch disc recess in the case. The recess inside of the case makes it slightly weaker than a standard open diff case. It's difficult to weld into a spool if that's your thing. Basically, they don't work well, so don't waste your money. You're better off with an open diff.
EATON DETROIT TRUETRAC (LSD - Not to be confused with the locker)
This is what I would go with as far as LSD if you need/want it. It's an aftermarket LSD option that uses worm gears instead of clutch plates. They do not wear down over time. They also give you a better locking percentage to the non-spinning wheel. If the quote below is true, and you see a 3:1 Bias Ratio, that translates into 50% more torque transferred over from the spinning tire, to the tire with more traction.(after my original writing of this I'm pretty sure it has a bias ratio range 2.5 to 3.5:1 depending on how it is preloaded)
Exploded View - Inside the Eaton TrueTrac Differential - YouTube

LOCKERS
I'll talk about lockers here hopefully to illustrate the difference from LSD .
PART TIME LOCKERS - What a Rubicon has
Where as LSD would transfer at most 50% more torque from the spinning tire(Maybe more with BLD kicking in), to the tire with more traction. Lockers will allow all the available power to be applied to the high traction tire regardless of the other wheel. They will shine the brightest over LSD when one tire gets little or no traction (like in the air). You only want to used them when you really need them because they are very stressful on the axles when turning. Basically requiring the inside tire to slip. It's worth noting, if your using front lockers, it makes turning not as sharp(because the wheels have to slip). The lockers are controlled with a button or switch. The factory Rubicon lockers (not mod-ed) will only work in 4-Low going less than 25mph. They are strictly for off road, or getting unstuck situations. Reasons to mod the lockers for 4-High would be situations like sand and mud. Just keeping them on all the time off-road isn't a great idea. On off camber situations they can cause you to slip down a hill if both wheels spin and thus loose traction.
FULL TIME AUTOMATIC LOCKERS
There is also full time lockers (Like the Eaton Detroit Locker, or Yukon Grizzly Locker) that are more for trail rigs. They do not have a switch, and work mechanically without needing activation. They can be driven on the road. When turning they will allow the outside wheel to ratchet forward if no, or little, power is applied. They will not be a like stock ride. You will know and feel they are there when turning and hear them also.
Detroit Locker - YouTube

I'm going to throw down a copy paste job from poster Dynatrac. It was taken from another forum and goes a bit more in depth.
LINK-> JK-Adventure.com, a jeep forum for your Jeep JK.
Quote:

A clutch style LSD uses spring pressure (preload) to work at slow speeds (or light torque input). At greater torgue input, like leaving the line during a drag race, the pressure angle of the gear teeth design apply the majority of force. To allow a vehicle to navigate a corner, the outside tire must be able to go faster than the inside or the inside tire will drag. On a clutch driven LSD this is accomplished by traction of the outside tire overcoming clutch and/or spring pressure. On low traction surfaces such as ice, traction will usually not provide enough torque to allow that slippage for cornering. In some situations this is very good as it will allow you to leave a slippery stop sign, but at other times it will cause you to understeer through a corner.

A Truetrac LSD is a helical gear design (no clutches) and acts like an open differential until it senses a difference in torque loads from one side to the other. When torque loads differ, the internal helical gears slightly bind to the case and send more traction to the side that is sensing more torque. In a slick environment you'll get the extra traction you need without the understeer so common with a clutch driven LSD.

The bias ratio of an LSD plays a big part in its effectiveness. Bias ratio is the amount of torque that can be transmitted from one side to the other in low traction situations. As an example, take a 2wd car on a corner with ice on the right side but bare, dry pavement on the left side. Due to the extremely slick condition on the right side, it may only take 30 lbs. of torque to spin the tire. The factory Trac Loc has a bias ratio of between 1.6 and 2.0. Using the 2.0 ratio as an example, this means that in a low traction situation 2x the torque of the bad side will be transferred to the side with traction. In the case of our example where 30 lbs. of torque was enough to spin the tire, 2x or 60 lbs. of torque will be transferred to the other side. Depending on the situation, 60 lbs. of torque may or may not provide enough push to move the vehicle. A better LSD with more bias has a better chance of moving the vehicle. A Truetrac has nearly a 3-1 bias ratio. Some clutch driven LSDs (not the Trac Loc) can be tuned to get a better bias ratio. This is normally used in high performance street cars. While this tuning can help a vehicle in the above situation when leaving a stop sign, the added pressure required to break the clutches free during turning would cause the vehcile to greatly understeer on a slick road.

In the case used above, if the bias ratio torque wasn't enough to move the vehicle, the tire with no traction would free spin just like an open differential. During this free spin condition the clutches in the clutch driven LSD would be experiencing accelerated wear and the bias ratio is reduced. Over time, and sometimes it doesn't take long, the clutch driven LSD would act as an open differential due to excessive clutch wear. The Truetrac doesn't wear during a free spin condition. It will never need to be rebuilt and should last the life of your vehicle. Additionally, a clutch driven LSD requires a friction modifying agent in the gear oil help the clutches work properly. A Truetrac doesn't require a friction modifier and is best with plain 90-140w dino oil.

Most users have heard that by applying a lttle brake when in the spin condition an LSD will work better. This is true. Using the example shown earlier, if we add the brake into the equation, we might be able to boost the torque the differential senses- the brake adds resistance which increases the torque level. This added resistance/torque, may just be enough, when multiplied, to move the vehicle.

tlminh 09-26-2012 06:41 PM

Wowzers, the above post has taught me so much about the jeep!

So I have a JKUS without ASD (ie, BLD only)

Does the BLD work for both the dana 30 (front) and dana 44 (rear)

Same question about e-lockers on the rubicon. Are they front and rear as well?

SilverSport 09-26-2012 06:51 PM

BLD works on both front and rear axles.

The Rubicon has e-lockers front and rear.

Rooster76 09-26-2012 07:12 PM

You might find this video interesting. It covers the BLD (break lock differential) system
The Jeep® Command-Trac® 4WD - YouTube

MeadHawk 09-26-2012 07:40 PM

The way I understand it is the Auto LSD would mostly be beneficial when in 2 wheel rear wheel drive when BLD is not in operation. BLD is functional only in 4 wheel low and high which will pretty much make the LSD useless as the BLD will be doing the same thing but using yours brakes to do it.

Rooster76 09-26-2012 09:11 PM

I'm sort of curious what does DSA (as in the title of the post) stand for. It seems that Jeep's marketing department is way too creative in coming up with new names, for things with names :nonono:.

Quote:

Originally Posted by MeadHawk (Post 2833276)
The way I understand it is the Auto LSD would mostly be beneficial when in 2 wheel rear wheel drive when BLD is not in operation. BLD is functional only in 4 wheel low and high which will pretty much make the LSD useless as the BLD will be doing the same thing but using yours brakes to do it.

BLD WORKS IN 2WD ... Right? :confused:
Looks like that command trac video just muddied the water. I think BLD works in 2WD. The official Jeep command trac video (couple post above) makes it seem like it is a 4WD only option. I have found a few post that echo that it works in 2WD, but nothing that absolutely put's it to bed.

BLD will enhance LSD giving the axle a higher locking factor. They both are trying to lock the axle and do it in different ways by putting more friction(resistance) on the spinning tire=more toque=more ablity to push and not just spin. They don't counter act each other, or replace each other. I'm very certain that this is the case.

oilwell1415 09-27-2012 08:36 AM

It always amazes me that the people who have no idea how a clutch type LSD works are the ones talking about how horrible they are. They don't sense anything and they doesn't respond by sending power to the other wheel. They are ALWAYS sending power to both wheels. They allow the wheels to slip during a turn. The more torque you put in the harder they lock both wheels together. It is true that they never fully lock and that the clutches wear out over time. The former isn't that big of a deal unless you are a hardcore wheeler and the latter can be easily fixed every few years with a $70 set of clutches and an hour of your time.

The owner's manual says that BLD works all the time, but it is not a replacement for a LSD for several reasons. First, it is a reactive system. A wheel has to slip for a few seconds before it takes action. An LSD works to prevent the wheel from slipping in the first place. Second, when the BLD is working it reduces the torque available at the tire with traction by half. An LSD supplies full torque to both wheels until the difference in torque between them becomes so great that the clutches slip.

BenDiem 09-27-2012 12:49 PM

Wow, great info...

Thanks for the informative posts Gents; I just have a couple more questions relating to the OP's post...

Still slightly confused::facepalm:

1. For a mall crawler, is DSA worth the small increase in price ($295)?
2. Does DSA provide a benefit in 2WD or 4WD mode, or both? The answer to this question will be the deciding factor.
3. Is DSA a maintenance issue for mall crawlers in the future?

Tks/B

panthermark 09-27-2012 12:59 PM

Quote:

Originally Posted by BenDiem (Post 2835630)
Wow, great info...

Thanks for the informative posts Gents; I just have a couple more questions relating to the OP's post...

Still slightly confused::facepalm:

1. For a mall crawler, is DSA worth the small increase in price ($295)?
2. Does DSA provide a benefit in 2WD or 4WD mode, or both? The answer to this question will be the deciding factor.
3. Is DSA a maintenance issue for mall crawlers in the future?

Tks/B

1. IMO, yes...but that also depends on where you live. If you live in....Dallas...and every road around you is paved and dry.....you might not need it is much. But if you live someplace where you have to deal with slick, wet roads, or lots of gravel...you should get it.

2. It is located inside of the the pumpkin on your rear axle and is always "on"....so it helps with both.

3. Yes, every 40,000-50,000 miles (depending on wear). But keep in mind that if you never replace the clutch packs, it will eventually perform like an open differential anyway.

LSD is a must have deal breaker for me. I know there are better units available, but not installed for $295 MSRP.

If you are going to do hard-core off-roading....save your money and get something different. But if you will be a mall crawler (as I will be), and you have to deal with slick roads, and patchy ice in the winter......get it.

oilwell1415 09-27-2012 01:17 PM

Quote:

Originally Posted by panthermark (Post 2835674)
1. IMO, yes...but that also depends on where you live. If you live in....Dallas...and every road around you is paved and dry.....you might not need it is much. But if you live someplace where you have to deal with slick, wet roads, or lots of gravel...you should get it.

2. It is located inside of the the pumpkin on your rear axle and is always "on"....so it helps with both.

3. Yes, every 40,000-50,000 miles (depending on wear). But keep in mind that if you never replace the clutch packs, it will eventually perform like an open differential anyway.

LSD is a must have deal breaker for me. I know there are better units available, but not installed for $295 MSRP.

If you are going to do hard-core off-roading....save your money and get something different. But if you will be a mall crawler (as I will be), and you have to deal with slick roads, and patchy ice in the winter......get it.

This. And don't forget that the "Rear axle housing and ALL internal parts" are covered under the 5yr/100k mile powertrain warranty, so you won't have to worry about it for a long time.

NWranglerS 09-27-2012 03:26 PM

Can someone briefly explain the difference between the traction control that comes stock and the upgradable Limited slip diff?

MTH 09-27-2012 03:40 PM

Quote:

Originally Posted by NWranglerS (Post 2836140)
Can someone briefly explain the difference between the traction control that comes stock and the upgradable Limited slip diff?

See Rooster's detailed post above. He has a separate section each for the BLD system (the "traction control") and the upgraded LSD.

In short, the BLD system uses the brakes to reactively simulate an LSD. An LSD sits in the center of your axle housing a proactively does its job.

mcgee10 09-27-2012 04:21 PM

BLD is not taking you very far off road. Better try it out a few times first and have a friend with you that has a strap or a winch. My first trip out I knew it wasn't going to work for me. For some mild off road your BLD may work.

Rooster76 09-27-2012 05:46 PM

You use steel to sharpen steel, and one friend sharpens another.
 
BLD=ELSD(electronic limited slip differential - another term used in the Chrysler blog link above)=Part of the traction control system
I found a way better video showing BLD in action
2008 JEEP JK Brake Lock Differential(BLD) - YouTube
I found BLD mentioned in the 2012 manual on page 419 under traction control. It doesn't mention anything about only working in 4WD like the video implies.

2012 Owner Manual
Quote:

Traction Control System (TCS)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake
pressure is applied to the slipping wheel(s) to provide
enhanced acceleration and stability. A feature of the TCS
system functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. This feature remains active even if
TCS and ESC are in either the “Partial Off” or “Full Off”
modes. Refer to “Electronic Stability Control (ESC)” in
this section for further information.
Here is what the owner manual says about Trac-Lok. Guess that clears up the right spelling. Figured I would add it because I had the owner manual open.

2012 Owner Manual
Quote:

TRAC-LOK REAR AXLE — IF EQUIPPED
The Trac-Lok rear axle provides a constant driving force
to both rear wheels and reduces wheel spin caused by the
loss of traction at one driving wheel. If traction differs
between the two rear wheels, the differential automatically
proportions the usable torque by providing more
torque to the wheel that has traction.
Trac-Lok is especially helpful during slippery driving
conditions.With both rear wheels on a slippery surface, a
slight application of the accelerator will supply maximum
traction.
Quote:

Originally Posted by oilwell1415 (Post 2834918)
It always amazes me that the people who have no idea how a clutch type LSD works are the ones talking about how horrible they are. They don't sense anything and they doesn't respond by sending power to the other wheel. They are ALWAYS sending power to both wheels. They allow the wheels to slip during a turn. The more torque you put in the harder they lock both wheels together. It is true that they never fully lock and that the clutches wear out over time. The former isn't that big of a deal unless you are a hardcore wheeler and the latter can be easily fixed every few years with a $70 set of clutches and an hour of your time.

With LSD more torque will get transferred over from the tire will less traction (slipping) to the tire with more traction. It is expressed as "Bias Ratio" (most common) or a "locking factor" %. These terms exist because it is a phenomenon. (there is more about that in my quote from above)

Trying to find a good picture I found Trac-Lok replacement clutch plates on Quadratec for $116. They are show in #10 from->Jeep® Wrangler JK Axle & Differential Parts - Quadratec
http://www.quadratec.com/jeep-replac...na-44-rear.jpg


The owner's manual says that BLD works all the time, but it is not a replacement for a LSD for several reasons. First, it is a reactive system. A wheel has to slip for a few seconds before it takes action. An LSD works to prevent the wheel from slipping in the first place.

I agree Trac-Lok LSD is always at work trying to hold the plates together. The clutch plates are preloaded with tension. They act like a break being applied to hold both sides rotating at the same speed. For that reason they will pick up faster. I would tend to think it would be smoother because it is exerting more of a constant pressure. The BLD that sort of looks jerky from the video when it kicks in.

Second, when the BLD is working it reduces the torque available at the tire with traction by half.

I'm pretty sure that only the spinning tire gets the break applied. I don't think it puts the breaks on both wheels on the axle that would reduce some torque.

An LSD supplies full torque to both wheels until the difference in torque between them becomes so great that the clutches slip.


panthermark 09-27-2012 06:38 PM

I know there are a couple of packs available....but I'm trying to see if these are the correct ones.

Standard D44 - $66.61 + $8.02 shipping
Dana 44 & 9.25 Chrysler TracLoc clutch kit. : Amazon.com : Automotive

Aggressive Pack D44 - $129.49 + $8.02 shipping
Dana 44 Power Lok clutch kit,aggressive posi. : Amazon.com : Automotive

SilverSport 09-27-2012 06:44 PM

Are you trying to put Trac Loc in an open diff? The carriers are different.

panthermark 09-27-2012 06:47 PM

Quote:

Originally Posted by SilverSport (Post 2836697)
Are you trying to put Trac Loc in an open diff? The carriers are different.

I think he is trying to figure out if he wants to order LSD or not.....and how much possible replacement packs cost down the road.

Frogy 09-27-2012 06:58 PM

I had a trac lock on my 93 wrangler and liked driving my jeep over my brothers with an open diff on roads, but the trac lock was not very effective off road, my tl blew up ( carrier cracked) at about 170 k and I went to a Detroit, which is really not for the faint of heart. If I had to choose my ideal I like the idea of ected's but have heard they're crap. My answer to the original question would be get the tl if you don't plan on a real locker soon, you will enjoy the tl over an open diff

oilwell1415 09-27-2012 07:12 PM

Quote:

Originally Posted by Rooster76 (Post 2836491)
I've done my reply in a goofy fashion that prevents it from being quoted and easily responded to, so everyone now gets to suffer through bouncing back and forth to see what was previously said.

With a clutch type LSD there will never be more torque on the wheel with traction than there is on the one with no traction. All these types of diffs do is limit how readily the two axles slip compared to each other, hence limited slip.

If QTec gets $116 for them they are overcharging. You can get them a lot cheaper than that as shown by another poster already. They are covered by the powertrain warranty anyway, so it really doesn't matter what they cost.

You are correct that the BLD only applies the brake to one wheel. If you look at the mechanics of how a differential works you can easily see that if one wheel is locked only half of the torque goes to the other wheel because of the way the spider gears interact. With one wheel locked all of the power goes to the other side, but the tire spins twice as fast at half the torque.

oilwell1415 09-27-2012 07:12 PM

Quote:

Originally Posted by panthermark (Post 2836713)
I think he is trying to figure out if he wants to order LSD or not.....and how much possible replacement packs cost down the road.

The first two or three should be covered under warranty.

Rooster76 09-27-2012 08:33 PM

"The wise man knows he doesn’t know. the fool doesn’t know he doesn’t know." ~Lao Tzu
 
Quote:

Originally Posted by oilwell1415 (Post 2835733)
This. And don't forget that the "Rear axle housing and ALL internal parts" are covered under the 5yr/100k mile powertrain warranty, so you won't have to worry about it for a long time.

I would doubt that the Trac-Lok clutch plates would be covered under warranty because they are a wear item. I know that manual transmission clutches and break pads are not. I'm sure you could ask a service guy while at the dealer and they would be able to tell you.

Quote:

Originally Posted by oilwell1415 (Post 2836795)
With a clutch type LSD there will never be more torque on the wheel with traction than there is on the one with no traction. All these types of diffs do is limit how readily the two axles slip compared to each other, hence limited slip.

How do I put this. Your Wrong. Don't take my word for it just do a search for Bias Ratio and you will see. Here is a quote below from a link I found that goes over Trac-Lok on TJ's.

Quote:

FROM Off-Road Adventures Magazine
How much limited slip action a particular diff will generate is built in. That effect can be measured and is expressed as the bias ratio. Bias ratio describes how much torque the limited slip can shuttle from the lower grip to the higher grip tire. The rear Truetrac used for our TJ has a bias ratio of around 3.5:1. That means for every 100 pounds-feet of grip the low traction tire can support, the Truetrac can deliver up to 350 lbs./ft. to the high traction tire. That low traction side figure will include the built-in braking force of the limited slip as well as whatever grip the tire can deliver (there's always a little grip, unless the tire is in the air). That 3.5:1 ratio remains constant.
also worth noting from that article
Quote:

They (clutch LSD) work well, though as the clutches wear, their performance tends to degrade.
Here is another web site showing it transfers more torque over, hopefully to put it to bed. At least it will rest my case.
Quote:

FROM HowStuffWorks "Locking and Torsen"
For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.
Quote:

Originally Posted by oilwell1415 (Post 2836795)
If QTec gets $116 for them they are overcharging. You can get them a lot cheaper than that as shown by another poster already. They are covered by the powertrain warranty anyway, so it really doesn't matter what they cost.

It's possible. I also don't like how they make it harder to get free shipping anymore (no google checkout trick). Like I said It just popped up when trying to find a picture so I figured I would put what they charge for reference.

You seem to be really pissed off that I wouldn't get the factory LSD. It's not going to make your Jeep any worse. Maybe you have to add some special lube additive to the diff, but that's no big deal. In the end it is just my opinion. Like assholes everyone's got one and most of them stink.

SilverSport 09-27-2012 10:06 PM

I believe the "DSA" is just the option code Jeep uses for the Trac Loc LSD. Not aware of it meaning anything in regards to the LSD itself.

The 2012 Warranty Information book explains in Paragraph 2.1F the clutch discs are only covered under warranty for 12 months or 12K miles.

Paragraph 2.4E (Parts Covered) (Four-Wheel Drive (4X4): "axle housing and all internal parts. I read that to say the clutch packs would be covered under the 5 year/100K mile powertrain warranty.

oilwell1415 09-28-2012 07:57 AM

Quote:

Originally Posted by Rooster76 (Post 2837014)
I would doubt that the Trac-Lok clutch plates would be covered under warranty because they are a wear item. I know that manual transmission clutches and break pads are not. I'm sure you could ask a service guy while at the dealer and they would be able to tell you.

Read the warranty book. The diff clutches are not listed under the what's not covered section, and the rear axle section of the powertrain warranty specifically says that all internal parts are covered. The last I checked the diff clutches were an internal part of the axle. They may balk at changing them, but their own warranty manual legally obligates them to change them.

Quote:

How do I put this. Your Wrong. Don't take my word for it just do a search for Bias Ratio and you will see. Here is a quote below from a link I found that goes over Trac-Lok on TJ's.

also worth noting from that article

Here is another web site showing it transfers more torque over, hopefully to put it to bed. At least it will rest my case.
How do I put this. You DON'T KNOW THE DIFFERENCE BETWEEN A TORSEN TYPE DIFF AND A CLUTCH TYPE DIFF and you are in here telling us how they work? Do about 30 seconds of googling and get yourself to a point that you can actually speak intelligently on the topic. One article you mentioned specifially said it had a Truetrac and the other specifically said a Torsen. Both of these are Torsen type GEAR diffs. They are not the clutch style like the OEM Trac-Lok unit. Good God man, you posted a video of the Truetrac (with a description that says it uses worm gears instead of clutches!) in post 6 and a picture of a clutch type in post 19. Did you not notice at all that the two work in a completely different way?

Quote:

You seem to be really pissed off that I wouldn't get the factory LSD. It's not going to make your Jeep any worse. Maybe you have to add some special lube additive to the diff, but that's no big deal. In the end it is just my opinion. Like assholes everyone's got one and most of them stink.
I don't care if you get the factory LSD or not. What irritates me is that people that don't have a clue how it works and have likely never even had one come into these threads and spout off about how bad it sucks and it's a waste of money. Then they proceed to tell the person asking the question that they should spend $1000 on a locker instead when their Jeep will rarely see dirt at all and will never be in a situation where it is more useful than the LSD for $240. Never mind that the LSD can work all the time while still being compelely streetable.

The heading you used for post 26 should be your motto.

12JKUR 09-28-2012 11:00 AM

This is gonna take me a bit to digest.

What is #25 on the exploded view of the diff above?

How does the term "open diff" come to play, what is "open"?

oilwell1415 09-28-2012 11:04 AM

Open means it is simply a regular differential. They call it that because there is an open hole in the middle of it where the guts of a limited slip or locker would be if it was one of those. It does nothing to force torque to the wheel with traction.


All times are GMT -5. The time now is 07:48 PM.