NFRs2000NYC

I come from the sports car world and my 2012 Sahara is my first Jeep. As you know, I have neither lockers nor LSD. In the future, I though about upgrading the diffs with lockers or LSDs. Now, I have been doing reading for the last 8 months about both of them, but never had any practical real world experience.

Now, without either of them, if I pick one wheel up off the ground, the open diff will just spin the wheel off the ground without giving the wheel ON the ground any power. Yes we have BLD, but I'd like to leave that out of this convo for practical matters.

Now, in the above scenario, lockers will "lock" the two wheels together giving both wheels 50% of the available power. Sounds great. However, we forget that one wheel is off the ground and is spinning 50% of the power into oblivion...seems like a waste.

Now in the same scenario, a good LSD is capable of removing all power from one wheel and giving it to the wheel on the ground, thus, giving the grounded wheel 100% of the available power, unlike the lockers which can only do 50%.

To the simple man like me (layman is a better term) it seems like a good LSD is far superior on paper than lockers.

Would love to hear your explanation as to why my thinking is incorrect.

Not meant to start any arguments, just genuinely interested in the topic.

Sommer13

The bit about lockers is a fair call, but an LSD wouldn't give 100% power to a wheel that was stuck if the other wasn't. It allows a certain amount of slipping before it stops itself, and it gives the power to the wheel that has less traction. So if you got stuck on a rock with 1 wheel in the air and 1 on the ground, the LSD would turn the wheel in the air after it couldn't turn the 1 on the ground enough.

As far as if they are a good buy depends on what kind of driver you are. Open diffs would be good for a city/daily driver that is kind of the "family car". LSD's are good to start off with for light off roading and such, an lockers are best for someone who takes their rig off road frequently and into rough terrain...

But you can also go for something that's 2 in 1. Some brands make lockers that can be disengaged for the highway, either by air compression, levers and cables, or electronically, and engaged for off road performance. And some lockers Permanently lock the axles together, which can be good off road, but bad for tires and gas on a highway...

NFRs2000NYC

So you are saying that essentially an LSD will try and turn the wheel on the ground...when it can't with the power given, it will then just send it to the wheel int he air, thus, not helping at all, where as the lockers will be sending power to the wheel on the ground no matter what correct?

Sommer13

Yes, LSD's and ASD's(anti-slip diff) allow for a certain amount of slip until it senses the wheel hasn't gained any ground and isn't turning. Then it will spin the other. Lockers will spin both wheels at the same rate.

NFRs2000NYC

Interesting. So I guess my decision needs to be made for 95% of driving where LSDs are superior and the 5% of the time where nothing but lockers will save you. Reason I say this is I've been told that lockers are not idea for higher speeds (like 30mph) and are not good to drive around with them engaged on tarmac with ice, snow, etc etc.

Sommer13

That's correct. Lockers will use more fuel on the highway and will at some point cause problems when you try to turn at certain speeds, as the locker would continually try to turn both wheels at the same speed. LSD's are definitely better for highway driving and inclement weather conditions. But IMO, lockers are still better, as long as they are the good ones that can be disengaged. Research ARB air lockers, or Eaton E Lockers.

NFRs2000NYC

Well the ARBs and Eatons are obviously the way to go. I prefer the Eatons because I don't need to run air, but an article on projectjk about the d44 eaton vs the ARB scared me a bit. They said that for the d44, the eaton is much weaker than the ARB, which is still the benchmark.

To your last sentenced...it seems like a lot of cons for daily driving/bad weather. Lockers on means difficulty turning and wear on tires etc. Lockers off=open diff meaning back to square one. Would it be idea to have an LSD in the front and a locker in the rear? Vice versa? Thanks for all the help BTW, learning this stuff takes time and good explanations.

Sommer13

Yeh, Eatons are better for a Dana 30, but theres always benefits and trade offs for every mod. ARBs are more expensive to set up with the on board air compressor, but you gain the use of a good AC if you need to air up your tires after some off roading or you get a TPMS sensor goin off...

As for getting one locker and one LSD, most people opt for getting a locker in the front and the LSD in the rear. The front locker can be used when you go to 4WD for some extra traction, and you'd have similar performance from your rear LSD. Then you can drive on 2WD and not have to worry about the locker in front wearing anything out, and have a working LSD for your daily driving...

NFRs2000NYC

I see. A concern I have (besides locking the wheels that steer) is that the front is a D30 and the rear a D44. Seems like the 44 could take more abuse than the 30. The last thing I want to do is start breaking things. I know I know, it's a Jeep, stuff will break, but I'd like to not help the problem along.

Sommer13

Definitely understand that. I have an '08 unlimited sport that can't handle what I'd like it to, so I'm trading it in for a '13 JKUR. The Dana 30's are good for the modest driver, but 44's are like the intermediary between stock performance and strength. Their are things that can be done to strengthen the 30's up like welding on gussets and installing axle sleeves, but there is only So Much you can do for them. Still, as you are concerned about strength yet appeal to a more daily driver kind of view, a Dana 30 with a locker that is only used sometimes can hold its own, if you are cautious about how you mod and know what your rig can handle when pushing the limits...