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4wd system

14K views 69 replies 10 participants last post by  rcguymike 
#1 ·
I am looking to buy a 2014 compass 4x4 with manual transmission but I would like to know how the 4x4 system works on the nonFDII models. this system would lock front and rear axel or just works like a simple awd vehicle?
I currently have a wk with qtII and it lets me lock the front and rear axels in low range, does this system work similar or it just locks with wheel slippage and don't have a lever to lock?
 
#39 ·
Oh no he didn't! aroundincircles just qouted a WIKI as an actual source of info! No wonder it included already discredited stuff....how much do you wanna bet someone in this thread had edited some of that wiki at some point? Shameful. That, ladies and gentleman, demonstrates the veracity of the FD2 fan.

http://en.wikipedia.org/wiki/Jeep_Patriot

Oh wait! Now I have proof:
"The FD2 system has no low range. It merely holds the lowest gears of the transmission just like leaving a manual transmission or a manually controlled automatic transmission in first gear. There is also no evidence from Jeep that there is any difference in the BLD system from FD1 & FD2."


I will wait for some official proof. It will be a long wait. Obviously it would have been presented if it existed. No wonder aroundincircles quoted that trash without citing it. Sad.
 
#40 ·
So If something isn't written it isn't true?

It does not seem to be very accurate or reliable as we have already shown the "low range" to be advertising hokum and puffery.

Yes there is no transfer case to casue a torque multiplication like real offroad vehicles, BUT having a different final drive ratio of 8:135:1 on a FDII makes it achieve a numerically higher crawl ratio as compared to a FDI

Because of the different final drive ratio a FDII at ANY speed with have a higher RPM than a FDI MK that would apply in "1st gear on a cvt"

Once again from this article (A Chrysler engineer mind you talking about the FDII system)
http://www.autofieldguide.com/articles/cvts-go-off-road

When the low-range mode is selected via a switch, a controller determines whether the vehicle is traveling at an acceptable rate of speed (the system can only be activated at speeds below 25 mph) and then engages a coupling mechanism, via specially developed software programming, to engage the secondary drive wheel while the CVT moves into a higher final drive ratio of up to 19:1, which is more than enough to traverse just about any dusty trail or rough terrain. Loddane dismisses any concerns over potential durability issues of operating a CVT at such output levels, adding that most of the attention during development was focused on perfecting the calibration and feel of the system. "We had to do a lot of work to make sure the low-range mode would operate like a traditional system from a customer standpoint, so that it would sound and feel familiar," he says. The CVT2L system will be offered on the Patriot as part of the Freedom Drive II package, which itself is geared for durable off-road use, with 1-in. higher ground clearance, additional body sealing and high-mounted drivetrain vents designed to support 19-in. water fording capability.-KMK

So, now you tell me where it states that a FDI CVT has those features listed above by a Chrysler Powertrain Engineer.
 
#41 ·
Isn't it funny that WIKI entry has been recently edited to say EXACTLY what you have been preaching on here?

For full disclosure I just put information up on there, citing a reference.

You haven't provided any concrete evidence other than "people complain about the CVT on forums" and "FDII is marketing mumbo jumbo" about the 6 speed auto in your patriot. Once again, show us your patriot and why its the same as a FDII
 
#42 ·
He seriously went in and edited the wiki so it would say what he wanted it to say?

HAHAHAHAHA...

Man this guy has some serious buyers remorse from what it sounds like? didn't he get banned from the other jeep patriot forum for being an idiot?

Everybody agrees that he is wrong, and yet he goes around making a complete fool of himself.
 
#43 ·
http://www.chryslercommercialvehicl...lities/data/pat/modules/limited/module-D.html

info from Chrysler about the Trail rated capability and performance.

and how about something you cannot change, the service manual:

"Split-friction surfaces (where one wheel has grip and the other side of the vehicle is on a low-friction surface) or where a wheel is suspended off the ground and spins in the air are common off-road situations. An open differential by nature directs torque to the wheel that has the least amount of grip, and in these cases, the wheel spinning on the low-friction surface or the wheel spinning in the air, which is undesirable. While some vehicles use locking differentials to help overcome this situation and provide a solid connection between two wheels on a given axle, Brake Lock Differentials (BLDs) are used on this vehicle as an effective solution.

Vehicles equipped with the Off-Road Group (sales code AWL) include a separate set of BLD calibrations that are designed for Off-Road mode use while crawling over obstacles, during heavy articulation activity, split-friction surfaces and other conditions. These BLDs provide an alternative solution to locking differentials found on other vehicles by replacing the locking differential with the brake control hardware that is already in place on the vehicle. The same hardware used for Electronic Stability Control is used for Brake Lock Differentials.

Under normal conditions with the vehicle in Off-Road mode, for example, assume that the Electronically Controlled Coupling directs 148 ft. lbs. (200 N·m) of torque to the rear differential and each wheel receives an equal share, 74 ft. lbs. (100 N·m) of torque.

When wheel speeds are unequal across a given axle, the BLDs respond. In this example, the vehicle is crawling over rocky terrain and the vehicle experiences heavy axle articulation that suspends the right rear wheel in the air and the wheel spins. The open differential ports all 148 ft. lbs. (200 N·m) of torque to the wheel in the air.

The Antilock Brake Module (ABM) senses the right wheel is spinning faster than its mate on the opposite side of the rear axle and clamps the brake caliper on the spinning wheel to stop it from spinning and form a solid connection across the axle. If 74 ft. lbs. (100 N·m) of brake force is applied to stop the spinning wheel, an equal amount of torque is ported to the wheel with grip. This allows the vehicle to continue moving forward. The amount of torque the BLDs can send to the wheel with traction is dependent on the amount of torque the brake caliper can hold. The brakes are capable of holding the amount of torque used in this example. "
 
#44 ·
This "definition" says nothing about the differences in the two systems. In fact it is not even referring to the MK. This code, AWL, is used across the line-up. Notice there is no mention of Freedom Drive 1 or 2? This could be info for a KL or WK2 or WK1 or...you get the point. Nothing in that excludes it from applying to both systems. Infact AWL is also used on JK's that have NO BLD function. Thanks for posting but your reaching reveals your character and honesty. Try again.

Wiki is nothing but edits. It is unreliable. That is why you quoted it like it was something but hid the source. I stand by my contentions regarding the veracity of these two fanbois. You still cannot come up with any info regarding the BLD differences as that post in no way shape or form cuts it. Just as you tried to hide a wiki quote you know to be made up to try to fool those who just glance at this. Not cool.

Exiting Wiki was to make my point that it is not a reliable reference source.
 
#45 ·
Aroundincircles "qoute" was about code AWL. Ladies and gentlemen I give you Code AWL....for a 2014 Grand Chero:
Off-Road Adventure I - $995
Front and rear outline white letters : and 245/70-17 and all-terrain tires; Terrain type selection; Selec-Terrain responsive suspensionfeatures driver selectable and electronic-control; Quadra-Trac II drive with manual & automatic selection and descent control system; Space-saver spare tire with steel rim; Underbody protection for fuel tank, for transfer case and for engine; Trail Rated badge; Trailer towing preparation includes: trailer hitch

Again: such reaching is tantamount to admission that your stuff is not defefensible
 
#46 ·
This came directly from my personal 2008 MK service manual. AWL refers to part of the FDII package. You can find that when looking up parts like for the suspension.

And yes Barbra we did land on the moon.

Get over yourself, you're wrong. Accept it, lick your wounds and go cower in a corner for a while.
 
#47 ·
If you can post some official and honest info do so. If not just stop. I will reply IF such info ever shows up. Of course if it was going to it would have by now. The fact that those two are frantically googling their fingers off right now for anything that is even close to the subject, like the AWL code hogwash above, is hilarious to think of...:cheers2:

Again that crap you posted says nothing about the differences between the two systems. And just as your wiki qoute...yeah, don't be surprised if people don't buy your story
 
#51 ·
And the trailer rating means what in regard to the BLD's? That the trash CVT was the only auto offered for a time is not news. THE FD1 must not exist as it is not on that list! And...as I said: re-read your commercial vehicle posting and circle where it says FD1 or Fd2 or what each has. I also showed you code AWL....
 
#53 ·
I don't know how much more simple this could be, From a 2008 Jeep patriot service manual:
Vehicles equipped with the Off-Road Group (sales code AWL) include a separate set of BLD calibrations that are designed for Off-Road mode

separate set of BLD calibrations that are designed for Off-Road mode - forming or viewed as a unit apart or by itself.
separate set of BLD calibrations that are designed for Off-Road mode - Programming parameters
separate set of BLD calibrations that are designed for Off-Road mode - set to engage when the lever is put next to "off road"

and you wanted proof that the AWL referred to a FDII patriot, you can see that right here in the owners manual:


I've never claimed that the patriot is a rock crawling monster designed to replace wrangler. This argument is that the FDII patriot has a more aggressive BLD programming than a FDI patriot when put into L "Off Road". I don't know how much clearer I could be on that fact.

and in regards to that video, That was a fun and challenging day, I had 0 mods on my patriot at the time, and was learning how to wheel from others. I'm proud of that day and of that moment.

I also have videos like this where I test the 4x4 modes, Drive, 4x4 locked, and L "Off Road" and from personal experience there is a significant difference in the BLDs between D and L.
 
#54 ·
Under normal conditions with the vehicle in Off-Road mode, for example, assume that the Electronically Controlled Coupling directs 148 ft. lbs. (200 N·m) of torque to the rear differential and each wheel receives an equal share, 74 ft. lbs. (100 N·m) of torque.

If you knew anything about grand Cherokee's you would know that NO grand Cherokee's ever came with an electronically controlled clutch as is being referenced in the above quote that AIC quoted. Grand Cherokee's have REAL transfer cases thus there is no need for an electronically controlled clutch mounted ahead of the differential like the MK's have. The information quoted is from the MK service manual.

I'm going to ask again because you keep ignoring my questions:

Where is your FDI Patriot, where is YOUR videos showing us your supporting theory, you can only gather so much from reading specs online, I want to see YOUR Patriot offroad showing it's superior BLD performance, all you have done is quoted online and have not given any solid real world evidence to support your ideas.
 
#55 ·
Sir

Listing the specifications for one system without listing the other does not prove your point. That one recipe includes ground beef does not preclude another *separate*recipe from including ground beef as well.

Thank you
 
#56 ·
#58 ·

Taken in [D] 4x4 unlocked, basically normal driving mode

Taken in [L] 4x4 unlocked, FDII's have this position, also some 2007 MK's have the L position (but doesn't say offroad, i'm curious to see how one of those would react in this same test)
Taken in [L] 4x4 Locked FDII Mode

Why the difference between videos 2 & 3
I'm guessing in video 2 the transmission is holding 1st gear (rpms would be higher than a FDI due to the higher final drive ratio on the FDII) and not upshifting and in video 3 the secondary drive wheel of the CVT is engaged jumping up the rpms (and lowering the gear ratio further)
 
#63 ·
Although I completely agree that the FDII Jeep Compass / Patriot 4WD systems carry a different set of calibrations as compared to FDI, it seems like the 14' Compass / Patriot (FDI) have a more effective traction control system with the new six speed. This link show my Compass easily 'walking' off an icy patch.

 
#64 ·
Which mode of ESP was this done in, the Full on mode, the partial off, or the full off mode (done by holding the esp button for 5 seconds until it dings).

Everything looks good there, I prefer to use the full off mode since it doesn't cut engine power, and uses the brake lock differentials to shift power between wheels.

I see it behaving much like other FDI's

Keep in mind, the FDII MK's function exacting like FDI vehicles when not in the FDII specific mode. If I can find similar terrain I will try to take a similar video.
 
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