Quadra Drive II in Current Jeeps

[Backwoods Rambler]

Ya....Quadra Drive II rocks...

http://www.youtube.com/watch?v=DlaHUN8j_dM

This WK has a 3 inch lift with skid plates and rock rails. It has the Hemi and Quadra Drive II. Pretty darn capable.

Nice vid.... @ 1:29 to 1:31 you can see the QDII clearly "locked up" ... very cool :victory:

 

[Backwoods Rambler]

Instead of swapping all the wiring and electronics, why not swap the axle, and rig the locker for manual operation? That should be possible right?

Hard to say - if it is just triggered by a solenoid then maybe there is something like that possible.

If it requires some kind of a funky waveform then all bets are off.

Likely the former.

Need to see the FSM. Any torrent files for these trucks out there yet?

I think someone with an ELSD equipped Jeep should try shorting out some wires to the differential to see what happens.

What's the worst that could happen? Throw a code (MIL)? I'd recommend flipping through the wiring schematic first though.

Who has a schematic?

Just seeing if anyone is interested in doing this, or maybe knows someone who has done it?

Inquiring minds want to know. :coffeedrink:

 

[SGNellett]

i have an 07 GC Overland CRD with QDII and yes, it locks front/rear/center but never selectable (although by picking different modes you can encourage the computer to lock more quickly). it's pretty intuitive and like the "AWD" system on the JK Sahara, only needs a little bit of wheelspin for the computer to figure out what's going on.

Man, I guess I am out of touch, I had no idea they did this..

 

[nwoods]

sounds to me like a few people in this thread should be on the Jeep payroll. apparently they know better than a team of "off road" engineers, how to program the QDII, Jeep's most advanced off-road AWD system to date; they have more experience between them, than the whole of Chrysler and it's long history of off-road vehicles.

Alex, I am a "new school" wheeler like you in that I've got a lot of off road experience in a Land Rover LR3 that has the ELSD system + traction control, viscous coupling in the center diff lock, and also a host of other related systems. I am also an "old school" wheeler with a Jeep with selectable air lockers.

I think you miss the point altogether that others have stated with respect to the QDII systems design parameters, function, and market usage.

Yes, the QDII is capable and effective for perhaps 100% of trails likely to be encountered by 90% of the WK's owners, but for those ten percent of hard core guys, there's going to be some real and tangible limitations. The Jeep engineers are indeed talented, but they are not targeting those 10% guys in their WK product. That's why they make the JK still.

So don't get too defensive about the WK. It's a good vehicle, but not as capable as a JK with solid axles (articulation), selectable lockers, and very low range transfer case.

 

[DrMoab]

and very low range transfer case.

Which is completely worthless on 90% of the trails that a JK could handle. I really wish they would offer the Rubicon models with the good old 2.72 to 1 low range ratio.

 

[Rick Havok]

Sounds good, but I would only want an manual over-ride so you can lock it in when you know you are about to get into trouble. It's better to lock before, than to start letting something slip and then lock it.

Much akin to quasi-AWD system. The majority of these systems these days don't have a differential in the middle. They simply have a clutch of some sort, and they are 2wd until something slips. That's usually too late, because once a wheel starts spinning, it's hard to make it stop.

No need for a switch, just put it in 4Lo and it does everything faster than you can blink.

 

[Rick Havok]

Which is completely worthless on 90% of the trails that a JK could handle. I really wish they would offer the Rubicon

Alex, I am a "new school" wheeler like you in that I've got a lot of off road experience in a Land Rover LR3 that has the ELSD system + traction control, viscous coupling in the center diff lock, and also a host of other related systems. I am also an "old school" wheeler with a Jeep with selectable air lockers.

I think you miss the point altogether that others have stated with respect to the QDII systems design parameters, function, and market usage.

Yes, the QDII is capable and effective for perhaps 100% of trails likely to be encountered by 90% of the WK's owners, but for those ten percent of hard core guys, there's going to be some real and tangible limitations. The Jeep engineers are indeed talented, but they are not targeting those 10% guys in their WK product. That's why they make the JK still.

So don't get too defensive about the WK. It's a good vehicle, but not as capable as a JK with solid axles (articulation), selectable lockers, and very low range transfer case.

I wonder what Mark A. Smith has to say about that. Being such a hardcore guy I'm sure you know exactly who he is.

 

[Rick Havok]

For on-road use in poor traction conditions (snow/icy), the ELSD system is far superior to a conventional 4X4 with selectable lockers.

The Jeep JK is available with a rear LSD and also with a Brake-Lock Differential system - it actuates either the right or left rear disk brake to deal with excessive wheelspin. Sound good, right? It is. But it's still not as good off-road as actual selectable lockers. That's why e-lockers are offered from the factory on the JK Rubicon models.

For off-road use, selectable lockers do provide an edge. There are times (mostly when mud or ice is involved) when you need to combine good line choice, a locked rear (or rear and front) diffs, and a little bit of momentum to get your through. In these situations, you'll want to have the appropriate axle(s) locked before you begin tackling the obstacle.

Granted, these obstacles are right at the limit of what can be accomplished by a given vehicle...but there are times when getting through relies on all the elements of that line/locked/momentum equation being there. With a ELSD system, you would have to wait for:

1. wheelspin to start
2. the computer to decide it's a problem
3. the diff to lock
4. the wheel speed across the axle to equalize
5. the non-spinning wheel on the axle to start providing forward impetus again

At that point, you may well have frittered away your forward momentum, leaving you looking for the best spot to hook up your winch.

With selectable lockers, you can go into the obstacle with the axle already locked - you will consistently get the same revolution speed on both wheel without having to wait for anything. For an experienced offroad driver who knows their vehicle, can read the terrain ahead, and knows when lockers will be needed, selectable lockers will provide better offroad perfformance in select situations.

ELSD and/or AWD is a far more advanced and civilized system than 4X4 with selectable lockers, and is better for 99% of all the "4X4" drivers out there...but if you're willing to accept a little less in the way of manners and performance at 60 MPH, you can get a little performance at 5 MPH. :smiley_drive:

That's not at all how QDII works. It operates as QTII until in 4Lo, then it's not only instant, it's very often predictive and can vector 100% torque to one wheel if necessary. There is no waiting. Lockers will never deliver 100% torque to one wheel if required. WK2's don't have the 4 wheel version, which is unfortunate, but they are still better than just rear lockers and it's cheaper to add front ones than both. The JK comes with open diffs, it's a Torsen gear set, nothing at all like ELSD... just open diffs LSD or not. Cars have that.

 

[Rick Havok]

I read a few of these posts and figured out fast that I'm not going to sit here replying to every misnomer and wishful criticism about QDII, so I'll just say this, and you guys take it however you want. I'm not always the most tactful person, I just spit facts. Sorry for that, no hostility intended.

I have a WK, not a WKII, so not all of this applies, but I posted a video of Mark A Smith talking about the WKII, so if you want authority, he's the guy. Google him... a lot! I'll post that vid again here and a link to my rig, Warhammer too. You can watch none, some, or all of that, and even go to my channel if you want more examples and if you do you will see I also had a 97 TJ. They're not all great because I haven't been able to get out and video everything, but you should get the idea, at least as climbing and wheel spin goes, and it's very similar in mud too. I hope this helps clear some things up.

The reason I have a WK is the 4 wheel QDII, but as I said the new ones are also great and you can always add a front locker if you want.

Mark A Smith Vid <- Watch this entire thing if you get a chance.

Warhammer Vid

 

[Todd n Natalie]

That's not at all how QDII works. It operates as QTII until in 4Lo, then it's not only instant, it's very often predictive and can vector 100% torque to one wheel if necessary. There is no waiting. Lockers will never deliver 100% torque to one wheel if required. WK2's don't have the 4 wheel version, which is unfortunate, but they are still better than just rear lockers and it's cheaper to add front ones than both. The JK comes with open diffs, it's a Torsen gear set, nothing at all like ELSD... just open diffs LSD or not. Cars have that.

This thread was from 2009.

 

[Rick Havok]

This thread was from 2009.

So? It's not irrelevant. The WK2 is still in production and WK's are still out there. Also, I just read it, so others will too if they're looking for WK threads.

 

[w squared]

That's not at all how QDII works. It operates as QTII until in 4Lo, then it's not only instant, it's very often predictive and can vector 100% torque to one wheel if necessary. There is no waiting. Lockers will never deliver 100% torque to one wheel if required. WK2's don't have the 4 wheel version, which is unfortunate, but they are still better than just rear lockers and it's cheaper to add front ones than both. The JK comes with open diffs, it's a Torsen gear set, nothing at all like ELSD... just open diffs LSD or not. Cars have that.

I understand that you're a fan of the system - and for good reason. In my current 5th gen ranger I'd actually prefer that sort of system to the manually selectable rear locker that I have in there. It's a far better choice for the type of driving that I end up doing in that Ranger. I took a look at the vid that you've posted, and I like what you've done with your WK. I also like the fact that you get it out and wheel it to the limit of what it'll do without worrying about the paint.

We can certainly possible to postulate about how many angels are dancing upon the head of the pin earned by sending 100% of the torque to one specific wheel. The honest truth is that's useful if you're in varying traction condition on icy roads or gravel, and it will be very serviceable for most off-road situations, right up until you find yourself in a situation where all of the wheels have marginal traction. Once you get to that point it is far preferable to have a constant and predictable flow of torque to both (or all four) wheels. In those situations, sending 100% of the torque to one wheel won't gain you anything other than having another wheel slipping because you're trying to put more torque through the interface between tire and surface than it can accept without slipping. Having a predictable flow of torque to a wheel whether it's in the air or on the ground is also beneficial when you know you're going to lift that wheel for part of the obstacle - when it comes down, it's still turning at the same rate as the rest of the wheels and it's going to contribute to your forwards motion at the very instant that it contacts the ground, without waiting for the computer to decide that it has an acceptable level of traction to start getting torque. For challenging off-road use like I get up to in my JK, there is no substitute for the ability to have your differentials actually locked. Over the past dozen years of fairly gnarly off-roading I've had the chance to see both fully locked diffs and a variety of limited slip and electronic systems in terrains including muskeg in Northern Canada, deep erosion ruts in the Canadian Rockies, extreme high altitude in the San Juans, slick rock in Utah, and goopy clay in Texas.

If you'd like, take a look at this clip of a situation where a constant, steady, predictable flow of torque to the wheels is beneficial. This is a little day trip that my father and I went on to a local area after we got back from a week in Moab. And yes, you're completely correct that there is an easy bypass immediately adjacent to the obstacle. I deliberately took a difficult line through the obstacle because I knew that I had both the combination of suspension travel, footprint from aired down 35's, and constant flow of torque to all four wheels that's required to maintain grip throughout the entire obstacle.

I actually wish that I had some video from my trip to Moab in 2017 with that same rig - the day that we did Golden Spike had some good examples of where having a wheel continue to turn at the same speed as the others was beneficial.

I am a huge believer in modern AWD systems for the way that 99% of all people use their vehicles, and I'd be delighted to have one in my chosen daily driver and foothills rambling vehicle....it's just not the right system to go into a vehicle that is being used by someone who is dealing with truly ugly obstacles and terrain. For your uses an AWD system looks like a great choice, I'm simply saying that for what I get up to in my Jeep it's preferable to have two locking differentials.

 

[Grassland]

What the Jk/jku guys forget is the wk/WK2 platform can also tow and offer decent highway manners.

As this is an expo page and not a rock crawler page, I'm surprised to see all the jk guys on here reminding everyone without an extra low range transfer case and selectable front and rear lockers how inferior their 4wd system is.
The qt2 and qd2 system has a locking mode and low range, so it isn't just some gussied up AWD system. It's just lacking mechanical lockers.
Not a lot of options on the market for a longitudinal engine RWD based true 4x4 that can tow over 3k lbs, seat 4 comfortably, and is somewhat affordable.
Off the top of my head 4runner, WK2, maaaybe the Lexus clone of 4runner gxwhatever if you consider it reasonably priced.

 

[w squared]

Hmmm. That criticism might hold water if the Jk in the video had not towed a trailer clear across the western US for a straight month of overlanding.

Or if I had not pointed out multiple times that QD is better for the vast majority of applications. And said that I wish my Ranger had a similar system instead of a manually locking rear diff. At no point did I ever say that QD is inferior. It is simply different. It’s better than a 4:1 transfer case and manual lockers for the vast majority of what people use vehicles for. The truth is, if you would benefit from low gearing, lockers, and live axles, you probably already know it. That said, just because you don’t understand why they benefit me doesn’t mean that they aren’t a benefit to me.

The purpose of my post was simply to illustrate my original point from years ago. Locking diffs offer an advantage in certain niche situations. They are a specialized piece of kit....and when employed in that specialized way, no quantity of marketing hype is equivalent.

 

[Rasberry]

I think a lot of people are misunderstanding what QDII on a WK is really like. I have experience driving plenty of vehicles, locked and unlocked. I had a 07 WK CRD with QDII. The system is not locked, that's true, but it's the closest thing to being locked front and rear without actually being locked front and rear. It's incredibly responsive and positive, and it feels like being locked front and rear when engaged. It's not just an AWD system, it has 4lo gearing to be engaged.

The system is incredibly underrated, I consider my WK as being way more off-road capable than my TJ. I've done White Rim, Black Bear, Engineer, and followed JK's on 35's through Moab. It goes anywhere an overland vehicle should go. It's definitely a vehicle for heavy off-road use, it's just overlooked.

Not to mention the fact that it is AWD in high range too. As someone mentioned above, I'm not sure how it could get any better for snow conditions.

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