Jeep Garage  - Jeep Forum banner

1 - 20 of 37 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
I would like to know if there is at least one jeep grand cherokee wk2 with a aftermaket rearlocker in the world.

May be somebody can give us some information.

I think ARB has a rear locker for the Wk2.


Thanks
 

·
Super Moderator
Joined
·
8,625 Posts
I haven't seen any evidence posted that anybody has found something aftermarket. There have been two threads that I remember asking about it, but...
 

·
Registered
Joined
·
200 Posts
There are no rear or front lockers compatible with the WK2.

Uneek4x4 was working for a few months some time back with an engineer specializing in differentials to try and bring something to the WK2, but they stopped that.

They may however look back into it in the future.

Seeing as they've dumped more R&D into the WK2, and have more products for it than anyone else, I wouldn't be surprised that IF WK2's do get lockers in the future, that it comes from them.

It's worth noting that there is an ELSD on the market somewhere, although I forgot where.
 

·
Registered
Joined
·
7 Posts
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.
 

·
Registered
Joined
·
27 Posts
I have thought about all this as well. Including calling other vendors to see if anyone is making a traditional locker. ARB etc. unfortunately only struck out.

I don't need it, it's my wife's GC, but I would be completely willing to buy the new rear axle. I feel like the rest could be done buy updating the software.

For instance I have a 2016 F150. It didn't have downhill assist. Amazingly I purchased the button for $15, and a connection to the OBDII port and my laptop. I was able to turn the function on in less that 5 minutes. As soon as I told the computer the function was there. It automatically new the button was plugged in. Everything worked perfect.

I just don't know enough about the system to understand what it needs to retrofit the system on the Jeep.
 

·
Registered
Joined
·
200 Posts
Full pressure is 100% locked with no pressure going to open diff.
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.

Especially since it's designed for stock tire and suspension setups. You're adding more pressure and force to the setup, which causes it to be even less effective(since its friction based. The more force you have involved, the easier its going to move, as the friction remains constant).

IMO it's not worth it, as the current open diff system, directing power by using brakes, works well.
 

·
Premium Member
Joined
·
1,360 Posts
FYI How the WK2 ELSD works, from the '14 FSM:
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.
 

·
Registered
Joined
·
200 Posts
FYI How the WK2 ELSD works, from the '14 FSM:
it's not normal you see diffs this complex o_O

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.
 

·
Premium Member
Joined
·
1,360 Posts
As an aside, the WK ELSD (front and rear) was a different animal.. it had a pump between the two axles which would apply hydraulic pressure to the clutch discs when the two shafts spun at different speeds.. and a solenoid valve to release that pressure.

When the going gets tough I'd rather be in my '07 QDII than my '14 QDII.. but most of the time I'd rather be in my '14 ;)
 

·
Premium Member
Joined
·
1,360 Posts
it's not normal you see diffs this complex o_O

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.
actually, it just drives a ball up a ramp.. really just an electronic lever..

tho myself I liked the gerotor pump and solenoid valve of the WK QDII better
 

·
Registered
Joined
·
7 Posts
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 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.

I think to your point, between the ELSD or BTC which can match that force better since they are both friction. The only difference really is I need to slip before the BTC will turn on (or the faster OEM ELSD). In the retro fitted case I could approach an obstacle already "locked" and avoid slip.

With that FSM bit about the WK2 ELSD it becomes more complicated. My BMW friend suggested replacing the full harness when adding ELSD, but this sounds way more complicated then hacking the rear diff.
 

·
Registered
2011 GC Overland
Joined
·
3,729 Posts
What was wrong with the mechanical limited slip differentials that made them want to replace them with this complicated mess?
 

·
Registered
Joined
·
525 Posts
What was wrong with the mechanical limited slip differentials that made them want to replace them with this complicated mess?
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.....
 

·
Registered
WK2 EcoDiesel 2016
Joined
·
137 Posts
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.....
How did u get factory LSD in the wk2? I thought you couldn't add it unless it came with it from factory.
 

·
Registered
Joined
·
525 Posts
How did u get factory LSD in the wk2? I thought you couldn't add it unless it came with it from factory.
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..............
 

·
Registered
2014 Summit 5.7 4wd 20" tires swapped to 18", added all skid plates
Joined
·
1,639 Posts
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..............
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.
 

·
Registered
Joined
·
8 Posts
I am really interested in this. Has anybody explored the option of using an LSD out of a 300C with a mechanical LSD? They are a 215 axle style diff and I am pretty sure the equivalent year 300's vs GC's run the same 5 speed transmissions.

I wonder if any of these products may work for the GC?
https://shop.quaife.co.uk/chrysler-300c-srt8-quaife-atb-helical-lsd-differential
Wavetrac LSD (Limited Slip Differential) for 215mm Rear, 2006-2008 6.1L SRT-8 & 2009-2014 5.7L Automatic Transmission Magnum, Charger, Challenger & 300C 48-309-185WK
 

·
Registered
Grand Cherokee wk2
Joined
·
2 Posts
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.
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.
 

·
Super Moderator
Joined
·
8,625 Posts
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... ;)
 

·
Registered
Grand Cherokee wk2
Joined
·
2 Posts
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... ;)
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.
 
1 - 20 of 37 Posts
Top