What is the point of the limited slip differential?

[mgroeger]

I got there LSD in my ‘19 JLU sport S and am disappointed in its performance in the snow. I was parking and my right rear wheel hit a patch of ice near the curb and I seemed to lose traction even though the left wheel was on dry pavement. I thought this should transfer power to the other wheel. Am I overestimating the value of the LSD? I had LSD on my 2007 Mini Cooper convertible and that thing never seemed to lose traction, even in snow and ice.

Sponsored

 

[tlmacson]

Does LSD have any benefit in the rain?

I got the LSD on my 3.6 Auto JLU mainly for when I'm running the Select Trac in 2WD. I am confident that it limits wheel spin during spirited acceleration especially from a dead stop. A few years back I had a Journey with the 3.6 and I was constantly backing off my acceleration to prevent front wheel spin. I also find that the LSD aids in quicker recovery when the back end starts to swing out in light dampness conditions. I try not to use full-time 4WD until I'm at least confronted with heavy rain or worse.

 

[rickyrobert]

You would have got the D44 either way bc you have a manual. The axle upgrade with LSD is on the auto.

Wait, is this the case? I guess me having a manual comes with some other perk. Besides being cooler than the auto drivers

 

[mgroeger]

Wait, is this the case? I guess me having a manual comes with some other perk. Besides being cooler than the auto drivers

Yep you guys are totally cool. I love watching all of my cool friends that have cool stick Jeeps stall as they crawl up and over the cool rocks and ditches. Totally cool... hehehe
Just goofing with you. I like stick and when it came time to by my LJ I had to have long conversations with myself about sticking with an automatic because I new it would see challenging obstacles on the trails and a lot of guys who had made the move from stick to auto shared their wisdom of holding out for a nice auto.
I can always tell a stick on the trail because as soon as they come up to an obstacle it sounds like a chatter box.

 

[word302]

Yep you guys are totally cool. I love watching all of my cool friends that have cool stick Jeeps stall as they crawl up and over the cool rocks and ditches. Totally cool... hehehe
Just goofing with you. I like stick and when it came time to by my LJ I had to have long conversations with myself about sticking with an automatic because I new it would see challenging obstacles on the trails and a lot of guys who had made the move from stick to auto shared their wisdom of holding out for a nice auto.
I can always tell a stick on the trail because as soon as they come up to an obstacle it sounds like a chatter box.

Meh. I very rarely stall and I tackle some pretty insane obstacles. Once I re-gear I doubt I'll ever stall. You must be wheelin' with rookies.

 

[rickyrobert]

Yep you guys are totally cool. I love watching all of my cool friends that have cool stick Jeeps stall as they crawl up and over the cool rocks and ditches. Totally cool... hehehe
Just goofing with you. I like stick and when it came time to by my LJ I had to have long conversations with myself about sticking with an automatic because I new it would see challenging obstacles on the trails and a lot of guys who had made the move from stick to auto shared their wisdom of holding out for a nice auto.
I can always tell a stick on the trail because as soon as they come up to an obstacle it sounds like a chatter box.

I'm just messing around too. If I was to build a hardcore rock crawling rig it would be auto. But that's what my RZR is for.

 

[mgroeger]

I'm just messing around too. If I was to build a hardcore rock crawling rig it would be auto. But that's what my RZR is for.

That's on the bucket list, trying out a RZR on some rocks.

 

[Maverick909]

just a little ebrake pressure would have dont the trick. LSD works pretty well for me. ive had it in snow, ice , mud and crawling rocks. It hasnt not gotten me anywhere my buddy with a rear locker has gone so far. i do plan on removing the LSD for lockers in the next couple years but for now the LSD is great!

 

[entropy]

Limited slip differentials that use clutch packs or gears require some traction on the slipping wheel in order to work. If the wheel that is slipping has zero traction it cannot work. Before the world of traction control and brake lock differentials you could pull your parking brake slightly to introduce some drag on the wheel in the air to help the posi a little. On a JL you shouldn't have to do this, the BLDs and the clutch packs should be able to sort it out.

Sort of an interesting thing, in the TJ the Rubicons used a gear style limited slip differential (that of course also had lockers) where the other trims used a clutch based limited slip.

That's just so much unnecessary work. Nobody can beat a modern good quality auto transmission like the one in the JL, either racing or wheeling. It is just impossible.

BUT the fun factor of a manual is definitely worth it. Along with it being cheaper, (most possibly) more reliable, and much simpler. I would have a manual if my wife could drive stick.

 

[word302]

That's just so much unnecessary work. Nobody can beat a modern good quality auto transmission like the one in the JL, either racing or wheeling. It is just impossible.

BUT the fun factor of a manual is definitely worth it. Along with it being cheaper, (most possibly) more reliable, and much simpler. I would have a manual if my wife could drive stick.

Seems like a great teaching moment. That is of course if you have a strong marriage

 

[Go Outside]

Since we have moved on to discussing the merits of the auto vs manual let me add that changing gears is how we punctuate our driving experience and it is best done in a manual.

 

[zyt]

It never changed, all Manual JLs come with M220 rear axle regardless of trim or model year. Yes, Rubicons obviously come with the wider M220.

This true. I wish I ordered the cold weather package over LSD if I had known Dana 44 come with 6SP manual.

 

[Halfdoor]

I find the LSD very useful. I have a long driveway ending on a country road and in heavy snows the snowplows pile deep snow onto the end of my driveway. My JK Rubicon would take several back and forth runs to get through it. No, putting it in low and engaging the lockers would not be wise having to stop and disengage lockers and low range once on the highway. My JLU with LSD has never once skipped a beat in those conditions. Same MT tires too.

 

[basinite]

I find the LSD very useful. I have a long driveway ending on a country road and in heavy snows the snowplows pile deep snow onto the end of my driveway. My JK Rubicon would take several back and forth runs to get through it. No, putting it in low and engaging the lockers would not be wise having to stop and disengage lockers and low range once on the highway. My JLU with LSD has never once skipped a beat in those conditions. Same MT tires too.

Your driveway sounds about like mine. LOL. Mine is a gravel road, which borders the neighbors hay field. I have similar issues with the snow ploys as you do. You hit the nail on the head and bring up "real world" conditions where LSD's really pay for themselves. Is a LSD superior to a locker? Never! Is LSD better than open? Absolutely!

 

[entropy]

Honestly there is a lot of confusion around the internet about the LSD in wranglers.

The LSD in the wranglers is developed by Dana, it is a torsen (torque-sensing) type limited slip differential that is designed to compliment BLD and therefore it is not very aggressive compared to other types that are designed to work as standalone units.

Does this mean it is trash? it isnt. It is really good actually and MUCH better than the regular open differential, yet not as good as a true locker for rock crawling.

To understand how it works, in simple terms. The JL wrangler LSD (trac-lok) has a torque bias ratio (TBR) of about 3:1. This means it can provide as much as three times of available torque to the tire with least traction. What else does this mean?. Well, it also means that it can provide torque to the tire with more traction as long as the TBR between both tires remains 3:1.

So while you are offroading, if the tire with traction can handle about 75% of the applied torque and keep moving, youre good. When the TBR exceeds what the LSD can handle, meaning the tire with traction needs more than 75% available torque, such as a situation with a wheel in the air, the LSD does nothing. In this scenario, a true locker will be able to provide 100% of available torque, and the LSD will provide 0%.

And this is why the LSD in the wrangler is not as good as BLD for rock crawling as a standalone unit. But, we have it paired with BLD. So what happens is that when you have that tire in the air, and BLD activates. The LSD sends about 3 times as much as that traction torque (drag from the brakes) to the tire with more traction.

So if you think BLD is good, the LSD is going to multiply the capability of the BLD system by about 3 times.

In my book, having a rear LSD in a wrangler is not as good as locker for crawling. But it is a damn nice unit, and with BLD the only downside compared to a real locker is the fact that it is reactive. It will also save your rear brakes from overheating while doing hard offroading.

My Jeep has 17k miles, I change the rear diff oil quite often and it looks pretty clean. When I do tire rotations I check that the LSD is working. I wheel my jeep quite a bit, and my LSD is still working just fine. Hope that helps.

Sponsored