You can't accomplish 100% "lock" with a viscous LSD.Full pressure is 100% locked with no pressure going to open diff.
The Electronic Limited Slip Differential Module (ELSD) (1) is a microcontroller-based assembly, controlling the rear axle. The ELSD can send 0 to 100% torque from the wheel that is slipping to the other wheel, on the rear axle. The transfer case controls slip from front to rear. The ELSD controls slip from left to right within the rear differential. The ELSD controls an electric motor which drives a gear set which moves a ball ramp to apply force to a wet clutch. This clutch is used to control torque split. Motor position feedback is done with two hall effect sensors on the motor. There is also a temperature sensor on the motor. ELSD will be temporarily disabled with high temperatures on the motor. Communication is via the CAN serial bus. Inputs include: Vehicle speed, Wheel speed, Terrain mode ELSD position sensor, and VIN, odometer for diagnostics. Outputs include: Actual rear differential torque, ELSD status, and PWM control of rear ELSD motor.
it's not normal you see diffs this complexFYI How the WK2 ELSD works, from the '14 FSM:
actually, it just drives a ball up a ramp.. really just an electronic lever..it's not normal you see diffs this complex
Most are simple mechanical devices, and the ELDs are typically just an electronic lever. I'd honestly be concerned about how something complex and electrical, plus having an actual motor in/near the diff itself, would hold up. But that's just me.
I think I understand this limitation. It really only needs to overcome whatever the combined frictional force is of the rear tires to the ground. If the ELSD can handle that then it is essentially 100% locked and both tires will spin out with enough power.You can't accomplish 100% "lock" with a viscous LSD.
They function based off friction plates. And you can not accomplish 100% lock with friction.
I agree!!What was wrong with the mechanical limited slip differentials that made them want to replace them with this complicated mess?
How did u get factory LSD in the wk2? I thought you couldn't add it unless it came with it from factory.I agree!!
I'm "old school", and the way I look at things, if it ain't broke, why try to fix it??
BTW, I spent a LOT of money, in order to get the factory LSD in my '15 GC Limited.....
Correct...........the LSD was part of an option package known as the "Off Road Adventure II" package, which was about $2000 extra. It included the Quadra-Drive group, the Quadra-Lift suspension, as well as several skid plates. However, in order to be able to order that package (at least in 2015), you had to order either the Hemi V-8 engine, for another $3000, or the diesel V-6, at around $4000.How did u get factory LSD in the wk2? I thought you couldn't add it unless it came with it from factory.
Yes, in cars it was a "posi" clutch type limited slip. In chevy trucks it was (maybe still is) a true locker, no slip at all once it locked, which it did if there was more then about a 1/4 rotation difference in tire spin. We had them on 4x4 work trucks. They are great for off road. They made a nice "clunk/bang" when they locked. Chevy used to do demo's at driveathons showing how even with only one wheel having traction you could keep going compared to the competition that just spun tires even with a LSD.Correct...........the LSD was part of an option package known as the "Off Road Adventure II" package, which was about $2000 extra. It included the Quadra-Drive group, the Quadra-Lift suspension, as well as several skid plates. However, in order to be able to order that package (at least in 2015), you had to order either the Hemi V-8 engine, for another $3000, or the diesel V-6, at around $4000.
In my case, I ordered the Hemi. So, overall, it cost me approximately $5000 extra, to get the damned LSD. Personally, I think that's outrageous! I'm old enough to remember, as well as have personally ordered a couple of Chevrolet cars, with LSDs, or as Chevy called it, "Posi-Traction", and it was a simple $50 option..............
Hi WK2PDX did you have any luck with this? Im looking at doing it myself. Ive sourced a rear ELSD diff for $1500 which is about the same as you would pay for an air locker anyways. It would be good to get comfirmation of this working from a switch as you mention above before pulling the trigger on purchasing the rear elsd and fitting it.So have been thinking about this and searching/reading. It looks like there maybe an LSD available, which I doubt would be much better than BTC I currently have. My jeep does have the 230mm ria without ELSD. Best I can tell the ELSD housing mounts the same as mine and uses same CV axle part numbers. I made the mistake of entering my email into a salvage site and must have 100 emails about a 230mm ria with ELSD housings for anywhere from 300 to $2000 depending on grade.
My understanding for how the jeep ELSD works is that there is an electrical pump that creates pressure on the ELSD clutch packs. The pressure is regulated by an electrically controlled valve/regulator that can release pressure to a reservoir. Full pressure is 100% locked with no pressure going to open diff.
What is stopping me from installing this rear end, powering the pump with simple PWM controller, and then flipping a switch to control the valve?
I don't think it's designed to be 100% locked for long periods of time. But 50% or 80%? Or 60s at 100% to get me through something? Should be no issue. It wouldn't be hooked into my PCM/DTCM so my jeep would just see less wheel spin when engaged. Jeeps with rear ELSD still have F/R BTC.
All of this could be answered with some signal monitoring on a jeep with ELSD. Especially to see if there is any power/signal arriving at the rear end during open diff driving and what it looks like in 4low. There are 2 connections. I'm assuming one for power and the other for control/feedback.
Am I wasting my time thinking about this? Would it be worth it? I've had situations where rear locker would totally save me from running a tight spot and having my jeep jump all over while traction is moving and tires spinning. Has anyone seen people try this transplant on a WK2? I did see some thread of a guy doing this on WK front.
At the moment this is the only option that I can find for us non ELSD guys for getting a rear locker as no company that I can find makes a diff lock for WK2's yet.Since the whole idea behind an ELSD (Electronic Limited Slip Differential) is for it to be automatic and engage when the vehicle senses the need for it and to the degree it's needed...operating it from a switch if that's even possible seems counter-productive in my mind. But I'm sometimes a weirdo like that...