Replacement rear diff carrier?

[NoMatter]

I've been looking into changing the rear open diff out for something a bit better, I know the ARB air locker works but it's kinda pricey and I also want something that will benefit me on the street seeing how my XK is a daily driver in Colorado. (snow) Correct me if I'm wrong but from what I've been reading I am best going with a limited slip like the Eaton Detroit Truetrac (912A553) over an auto locker like the Detroit locker (187C179A) or any of the lunch box lockers like Aussie,Lock Right etc..

From what I have read and seen videos of the auto lockers are noisy, clickity click click around corners and while gassing through corners they may lock which will almost cause you to drive it in a whole new manner.

The limited slip of the Truetrac also has it drawbacks, if one wheel is elevated while crawling this may cause the unit to open up leaving you with a similar setup as before but this can be overcome with creative braking using the e-brake will be enough to "lock" it back in? We all know the XK has a tendency to left a leg now and then.

I'm not quite sure what to do, leaning towards the Truetrac anyone with any thoughts??? Input??? I think having a new rear end may be a benefit especially in Moab this spring. Keep in mind "Daily Driver"


http://www.drivetrainamerica.com/p-35-912a553-detroit-truetrac-chrysler-825-29-spline.aspx

http://www.drivetrainamerica.com/p-725-187c179a-detroit-locker-chry-82529-spline.aspx

http://www.aussielocker.com/index.php/lockers/aussie-locker-xd-58229.html

[Holaday07 4.7]

I would stay away from the locker if you dont want to go with the ARB. I had a Detroit in my ZJ and it was great offroad, but sucked in snow and ice, also ate tires pretty quick. Whats wrong with the QTII system? If I am correct the ARB acts as a limited slip when not engaged, and gives you the option of a fully locked axel when turned on. Plus you get onboard Air.

My $.02 hope it helps

[NoMatter]

The QTII is fine but I would like a little extra grip and a thousand bucks for the ARB setup is a bit much. From what i read the ARB is normally open.

[superacerc]

My question is, If you go with a limited slip like truetrac what happens when the traction control steps in (or does it not work that way on the QDII)?

[Sal-XK]

If you get a wheel off the ground with QT2 you don't need to nothing the torque break traction control will stop that wheel and send the power to the other wheel. Unless you're really into off roading and do it all the time a locker is a waste of money. The computer system does a great job at handling just about everything you can throw at it. If you need more wheel slip just hit the ESP button once if you need a lot more slip hold it down til you here the chime. The best locker you can buy for on road use is a selectable one. I have had two wheels off the ground a lot and the computer has always kicked in kept me moving.

[Holaday07 4.7]

I have to agree. If you do not want to fork over the cash for an ARB I wouldnt mess with switching anything out. I will never put a locker in a DD that is not selectable again.

[NoMatter]

superacerc
My question is, If you go with a limited slip like truetrac what happens when the traction control steps in (or does it not work that way on the QDII)?
The traction control being brake biased only sees wheel spin so adding traction won't upset it any.


Sal-XK
If you get a wheel off the ground with QT2 you don't need to nothing the torque break traction control will stop that wheel and send the power to the other wheel. Unless you're really into off roading and do it all the time a locker is a waste of money. The computer system does a great job at handling just about everything you can throw at it. If you need more wheel slip just hit the ESP button once if you need a lot more slip hold it down til you here the chime. The best locker you can buy for on road use is a selectable one. I have had two wheels off the ground a lot and the computer has always kicked in kept me moving.
I've experienced problems when crossing over ruts when one wheel is slightly unloaded and the other is in full contact but the unloaded wheel seems to get all the power, While off road I always have the ESP full off in 4low, I hate when the traction conrtol kicks in from take off and "slows your roll" if you know what I mean? By the computer applying the brakes isn't momentum being lost? Correct me if I'm wrong but the QDII is an ELSD Limited slip, but not a complete locker only locking 60% It's my idea That adding traction with a new carrier would improve overall performance and by leaving the ESP in partial maybe the brake action of the computer would help the Truetrac perform better?

[Omelet]

The QD2 ELSD is capable of 100% lock.

[Sal-XK]

The QD2 ELSD is capable of 100% lock.

This is correct the QD2 will obtain full lock. I think it is a matter of how you're driving. While rock crawling which is what I mostly do I just put it in 4LO and don't touch the ESP this keeps the traction control touchy and reacts quickly to wheel spin. I tried it with the ESP off and yes it allows to much wheel spin for having wheels off the ground. Now in the sand and mud I will go in 4LO and hit the ESP button so I can have more wheel spin with out the computer jumping in. I found that this setting will allow enough wheel spin for most situations. The guys who need more wheel spin have tied the ABS fuse into a switch so they can have all the wheel spin they want. If your transitioning from snow to ditches so from needing lots of wheel spin to needing no wheel spin you need to be turning the ESP button on and off as needed. My only complaint so far with this system is it's not as controllable or say predictable as having a locker. But I don't think I would go without a select-able locker for a DD not with these things anyway. At this point in my build it's still the ground clearance and wheel articulation that holds me back right now.

[superacerc]

Yeah, in the slippery stuff some spin and momentum is needed. If you've got wheels in the air chances are you're not slipping and sliding around in the mud or snow so traction control is what keeps our rigs moving when wheels are off. Leave it on next time and try it. I never get stuck and rarely spin more than a half turn of a tire(and usually not that much).

[NoMatter]

Thanks for the correction on the QDII thats whats great about this place, knowledge all around... i too have never had a problem with getting stuck, well except that one time I got high centered on the crossmember. From what I'm reading unless it's an ARB it wont benefit me in any way? I too want more ground clearance and was hoping to do a superlift this winter but I need new tires anyway so thats an extra grand I cant afford on top of the lift....if my 265's had more life on them (almost 40k) I would have been fine, but for Moab I want new meats. I have wheeled with the ESP on on 4 low its does do great! (Esp is reduced correct) Unfortunatly the snow has put a stop to my adventures till at least May.
I thought having the mechanical advantage of the limited slip along with the QTII's brain would improve the XK's abilities. Especially if I ummm...decided to drive through a bowl in Moab, haha is that even doable with my OME?

[Sal-XK]

For the deep snow you can get maybe worth wiring a switch to the ABS fuse so you can disable it and spin as much as you want. The bowl LOL make sure you get a video of that please :) A selectable locker is really the best way to go but very expensive. If you don't mind a little noise some chatter and some extra tire wear then go for the other ones.. I'm sure someone makes one that will perform decent enough. I think at this point though a SL lift would benefit you more then a locker.

[NoMatter]

Oops I meant "tubs" the gravy bowl no frickin way I would try that with my XK

[superacerc]

it seems (at least in my mind) that the limited slip and traction control would work against each other if both were active. The limited slip needs one wheel to skip to activate the other wheel while the traction control is trying to stop that wheel that needs to slip so tbd the other will grip. With a locker the traction control won't sense a slip cause both wheels should be turning the same speed. In this case it would seem that it should work right, maybe.

[valpacer]

This is correct the QD2 will obtain full lock. I think it is a matter of how you're driving. While rock crawling which is what I mostly do I just put it in 4LO and don't touch the ESP this keeps the traction control touchy and reacts quickly to wheel spin. I tried it with the ESP off and yes it allows to much wheel spin for having wheels off the ground. Now in the sand and mud I will go in 4LO and hit the ESP button so I can have more wheel spin with out the computer jumping in. I found that this setting will allow enough wheel spin for most situations. The guys who need more wheel spin have tied the ABS fuse into a switch so they can have all the wheel spin they want. If your transitioning from snow to ditches so from needing lots of wheel spin to needing no wheel spin you need to be turning the ESP button on and off as needed. My only complaint so far with this system is it's not as controllable or say predictable as having a locker. But I don't think I would go without a select-able locker for a DD not with these things anyway. At this point in my build it's still the ground clearance and wheel articulation that holds me back right now.

Hey Sal,

I thought the traction control and esp turned off in 4 low completely? And you can manually disable it in 4 hi with the button press for 5 seconds? The elsd works in 4 low straight off the wheel speed sensors?

Dave

[Sal-XK]

Hey Sal,

I thought the traction control and esp turned off in 4 low completely? And you can manually disable it in 4 hi with the button press for 5 seconds? The elsd works in 4 low straight off the wheel speed sensors?

Dave

No you cannot turn off the traction controll system completely. We have a chart here somewhere that shows the different settings but I'm on my phone so I'll try finding it later. I think maybe the ESP can go full off. In the different modes different options get shut down. Like one setting kills the part that kills power during wheel slip but keeps the brake torque part active. The only way to completely shut down the abs is to disable it. I'll look for the chart when I get home if know one finds it first. Of course it changes between drive systems.

[superacerc]

^Correct. The traction control stays on while in 4 low. Otherwise it would be a useless system since we have no locking ability (except for LSD option on QDII). The Rollover/Skid protection part turns off in 4 low but without traction control we'd be stuck. My brakes get squeaky when i'm going slow and am in a dusty atmosphere so i hear everytime the traction control kicks in (even if it's a minor correction) i heard it plenty while at Big bend in certain hill climbing situations and going over heavily rocked terrain. Never needed 4 low though on that trip.

[valpacer]

Should have said I have QDII. To me it feels as if the Traction control is off in 4 low, the light is on and there is no feel of braking to the wheels when crawling 2 wheels off the ground. The ABS does stay on, thats permanent. Unless you get mud in the sensor plug.....another story.

Id love to see that chart Sal.

Dave

[Sal-XK]

Should have said I have QDII. To me it feels as if the Traction control is off in 4 low, the light is on and there is no feel of braking to the wheels when crawling 2 wheels off the ground. The ABS does stay on, thats permanent. Unless you get mud in the sensor plug.....another story.

Id love to see that chart Sal.

Dave

QD2 in 4 low I think operates with the clutch packs not with the brakes so you're correct. I think???? LMAO let me find that chart

[Sal-XK]

I can't find and can't remember who posted it I think it might have been Don. Hopefully someones memory will get jarred and know where it is. I'll keep looking though.

[valpacer]

Been searching, no luck yet. But if the TCS was still even partially operational in 4low this wouldnt be possible...


http://www.youtube.com/watch?v=6OIf0RMvr74

Dave

[Sal-XK]

Don sent me some links I'll check them out when I get a chance. I'm pretty sure in 4LO QD2 it's all the elsd doing all the work no brakes or anything.

[Matt]

I'm pretty sure you're right sal.... it wouldn't make sense to activate the brakes once the differentials are locked because that would thereby hinder both tires from rotating.

Also, on Sunday I pulled my friends 6500# 28' boat out of the water using a half beach/half paved ramp and had all 4 of my tires spinning in 4 low.... at no time did I hear my ABS pump kick in to activate the brakes, and I didn't even press the button to turn off traction control.

[Sal-XK]

With QT2 the brake torque is still activated for us or we would be just wheeling open open. As we hit the button were just basically telling the jeep how much wheel spin we need to get. At full off there is still a point where the system will kick in and try and stop the wheel from spinning on the QT2. QD2 I think the button has more to do with you guys in 4HI. Remember the QD2 system uses three things to fix wheel spin the brakes, engine power and clutch packs. As you change your setting you get a combination of these things QT2 obviously don't have the clutch packs.