Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Suspension/Driveline/Brakes/Wheels/Tires

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 12-27-2013, 05:26 PM
lt4vette's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: May 2013
Location: On a farm 200km north of Sydney Australia
Posts: 296
Thanks: 97
Thanked 13 Times in 12 Posts
Rep Power: 786
lt4vette is on a distinguished road
4WD behaviour

I have a 2014 Diesel Overland, and for the first time since I got it, need the 4WD on a steep grass slope. Unlike other 4WD vehicles I have (Landcruiser and Mazda), the Jeep seems to allow a fair bit of wheel spin before the system locks up to give the traction. maybe 1/2 to a full turn of the slipping wheel, then a loud clunk as it locks up, followed by the car jumping forward as it achieves traction. It seems to me that in difficult terrain, this would make smooth slow crawling up a hill wouldn't be possible. It happens in both Hi and Low ranges. I have only tried it in :auto: 4wd mode.
I'd like to know if may my Jeep has a problem, or is this just "normal" operation.
Thanks, Russell
__________________

__________________
2014 JGC Overland Cherry Red Off Road Adventure Package, ARB colour coded bar, 265/65/18 BFG's
Reply With Quote
  #2  
Old 12-27-2013, 06:07 PM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 2,843
Thanks: 68
Thanked 266 Times in 216 Posts
Rep Power: 5523
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 4WD behaviour

I have had the same in my Limited - 18" with Michelin Altitudes.
Although not that steep, I don't recall it locking it up, just spinning (rear) until I removed throttle input.
I tried it ICE & MUD setting incase the wet grass was like that, no difference.
Low range was a little better, but it is no even remotely steep enough to consider low range, and it still spun eventually.
Turning of Hill Assist also helped a little as it let the car move earlier in the rev range, but still spun.

This never happened in my 2005 Mitsubishi Pajero (Montero for US readers, Shogun for UK), which didn't have the electronic wizardry considered standard these days.

I thought it just must be the tyres, but even my RWD Ford Falcon sedan doesn't do it on the same section. It weighs 750kg less, with narrower even more street treaded tyres.

I though the system would detect the wheel spin far quicker than it does and stop it.
__________________

__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Could I get my avatar much larger?
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #3  
Old 12-27-2013, 06:12 PM
jakibe's Avatar
Member
 
Join Date: Dec 2013
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 274
jakibe is on a distinguished road
Which 4wd system do you have?
__________________
Reply With Quote
  #4  
Old 12-27-2013, 08:16 PM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 2,843
Thanks: 68
Thanked 266 Times in 216 Posts
Rep Power: 5523
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 4WD behaviour

My Limited is Quadra-Trac II, lt4vettes Overland is Quadra-Drive II.
__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Could I get my avatar much larger?
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #5  
Old 12-27-2013, 08:52 PM
f1anatic's Avatar
Premium Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jan 2013
Location: Illinoize
Posts: 954
Thanks: 5
Thanked 67 Times in 49 Posts
Rep Power: 158180
f1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond repute
Re: 4WD behaviour

I always thought this 1/2 to full turn wheel slipping is normal behavior associated with correctly working EDL (Electronic differential Lock) with or without the assist of the E-LSD on the back. When the clunk occurs, the brake system clamps the spinning wheel, transferring torque to the opposite wheel on the same axle and thus ensuring forward motion. The brake(s) only slow down the faster spinning wheel enough to match the rotational speed of the opposite wheel.

The other cars mentioned here either have locking differentials or mechanical LSDs and there will be no clunks. I have also experienced it in my 2014 Limited with ORA II 3.6 V6 QT-2 as well in both High and Low range.
__________________
Reply With Quote
  #6  
Old 12-27-2013, 09:05 PM
WK2OverlandII's Avatar
Quadra-Drive
My Jeep: 2014 3.0L WK2
 
Join Date: Nov 2010
Location: Clinton, Co. PA
Posts: 344
Thanks: 60
Thanked 4 Times in 4 Posts
Rep Power: 1750
WK2OverlandII is on a distinguished road
Re: 4WD behaviour

Quote:
Originally Posted by lt4vette View Post
I have a 2014 Diesel Overland, and for the first time since I got it, need the 4WD on a steep grass slope. Unlike other 4WD vehicles I have (Landcruiser and Mazda), the Jeep seems to allow a fair bit of wheel spin before the system locks up to give the traction. maybe 1/2 to a full turn of the slipping wheel, then a loud clunk as it locks up, followed by the car jumping forward as it achieves traction. It seems to me that in difficult terrain, this would make smooth slow crawling up a hill wouldn't be possible. It happens in both Hi and Low ranges. I have only tried it in :auto: 4wd mode.
I'd like to know if may my Jeep has a problem, or is this just "normal" operation.
Thanks, Russell
I know I had a problem with my 2011 Overland Hemi with the wheels slipping too much and there were many complaints from me and others. Jeep came out with a TSB reflash of the computer and it corrected it. I loved the fix as there was very little or no wheel spin when it kicked in after the reflash...it was awesome...it was like a totally different vehicle. Maybe ask your dealer to see if there is a TSB on it or if there have been other complaints.
__________________
2014 JGC Limited - Granite/Black - 3.0L ECODiesel - LUX II - NAV - Off Road II- Block Heater.
Reply With Quote
  #7  
Old 12-27-2013, 11:11 PM
jakibe's Avatar
Member
 
Join Date: Dec 2013
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 274
jakibe is on a distinguished road
If you look up videos of quadradrive 2 jeeps on YouTube you will see that the behavior you described is how it is designed to work. The thunk may be because the revs are too high??
__________________
Reply With Quote
  #8  
Old 12-28-2013, 12:03 AM
lt4vette's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: May 2013
Location: On a farm 200km north of Sydney Australia
Posts: 296
Thanks: 97
Thanked 13 Times in 12 Posts
Rep Power: 786
lt4vette is on a distinguished road
Re: 4WD behaviour

Thanks for all the responses.
Based on them, I'd make a couple of observations:
Snuke, you don't say whether you EVER got traction from the rear - did it lock up when you removed throttle input? The different behaviour between yours and mine (mine locking up) might be due to the ELSD diff with QDII.
I agree with f1anatic that the wheel spin seems to be normal (as per the videos jakibe mentions), but I do find it surprising.
Does anyone know how other electronically controlled 4WD's (Discovery. RangeRover for example) behave?
If they are all the same, then I'd have to say that electronic control is a retrograde step. My Landcruiser with mechanically lockable centre, front, and rear diffs as f1anatic says, does not behave similarly.
It is very interesting that WK2overlandII had the issues resolved with a fix - and quite worrying if it wasn't carried through to later models - certainly worth a check though.
A couple of things which may be related:
1. I first noticed it when trying to reverse an (empty) box trailer up a grassy slope. A wheel spun, clunked as described, but we went nowhere - engine revving and stationary. Selecting Low range fixed that issue, but weird - low range would not have been required in my other (mechanical) 4WD's. What would I have done if this had been on a hard surface? (I think I have seen another post on this issue actually).
2. Throttle lag from very low speed: If I'm crawling along (almost no throttle) coming to say an intersection) and decide I have time to get across if I accelerate briskly, I get no response for 1/2 to 1 sec, then wham - ejected across the intersection. I've learnt to control this by feeding in a small amount of throttle, waiting until the car catches up to the throttle position, then accelerating. Gave my wife a fright the first time she drove it though. Does anyone else have this problem? Maybe a diesel issue as it is likely turbo lag.
I think the throttle lag problem may be a problem in the clunk and jerk action of the 4wd - quite possibly by the time the wheel locked, the revs were too high, and .as jakibe suggests, that caused the clunk - or at least made it more severe. I'll try it again more gently.
But to the most important part: I haven't tried any "serious" 4wd'ing yet, and am concerned that the delay to locking or engaging wheels, combined with throttle lag, would make it very difficult to crawl up a steep rock strewn track - has anyone tried this?

Thanks, Russell
__________________
2014 JGC Overland Cherry Red Off Road Adventure Package, ARB colour coded bar, 265/65/18 BFG's
Reply With Quote
  #9  
Old 12-28-2013, 04:15 PM
ColdCase's Avatar
Senior Member
 
Join Date: Apr 2011
Posts: 1,446
Thanks: 0
Thanked 27 Times in 26 Posts
Rep Power: 26465
ColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond repute
Re: 4WD behaviour

I think you are seeing transmission issues, especially the lag. QD would have no influence on that behavior.

I've not had the same experience with my 2011 QD V8 and the older 5 speed transmission. I rarely get rear wheel spin, never have a bang... perhaps an occasional thump. I think you have more going on with the transmission, or perhaps transfer case.

Equipped with ELSD, when you apply throttle quickly the traction control computer will immediately lock or near lock the rear, no need for wheel spin. Mechanical systems must have wheel spin to work (unless externally mechanically locked in which case you have no diff function). In snow and perhaps rock mode the rear diff is near locked automatically. You shouldn't hear any banging unless perhaps you caught it in an awkward position with one wheel suddenly having zero traction.

You will get a banging type noise from the front BTC. If the fronts are spinning at a different rate than the rear, the throttle is pulled back.
__________________
2011 WK2 Overland Mineral Gray/Black, Advanced warning, V8; 2009 KK Rocky Mtn V6; 2000 WJ Laredo I6; 1979 CJ7 I6... green... miles of smiles :)
Reply With Quote
The Following User Says Thank You to ColdCase For This Useful Post:
  #10  
Old 12-29-2013, 01:04 PM
Member
 
Join Date: Jun 2013
Location: Washington
Posts: 250
Thanks: 0
Thanked 24 Times in 17 Posts
Rep Power: 1122
crabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond reputecrabman has a reputation beyond repute
Re: 4WD behaviour

I find the vehicle is smoother from a stop with eco turned off. It isn't just the trans shift points but also the throttle map that is altered in eco and I think it ends up being a bad combo. You get the eco trying to use less fuel until your commanded throttle input reaches a set point where it has been programmed to decide you want to move out smartly and then it ups the ante significantly to give it to you. Combined with a turbo diesel that is highly dependent on boost for power and you get a turbo that is just spooling up combined with a sudden large increase in fueling and bang, there is your surge. With eco off it acts like other diesels I've had where there is still a slight hesitation that you get around by giving it a little throttle to get rpm (and boost) up followed with a more substantial jab on the loud pedal which then moves you out smoothly but quickly. After a time you do this without even thinking about it and don't even notice it. Ive gone to switching out of eco as soon as the vehicle is slightly warmed up and I stay out of it till I'm on more open roads.
__________________
2014 Diesel Grand Cherokee
Reply With Quote
  #11  
Old 12-29-2013, 04:03 PM
f1anatic's Avatar
Premium Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jan 2013
Location: Illinoize
Posts: 954
Thanks: 5
Thanked 67 Times in 49 Posts
Rep Power: 158180
f1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond reputef1anatic has a reputation beyond repute
Re: 4WD behaviour

Quote:
Originally Posted by lt4vette View Post
Thanks for all the responses.


I agree with f1anatic that the wheel spin seems to be normal (as per the videos jakibe mentions), but I do find it surprising.
Does anyone know how other electronically controlled 4WD's (Discovery. RangeRover for example) behave?

If they are all the same, then I'd have to say that electronic control is a retrograde step. My Landcruiser with mechanically lockable centre, front, and rear diffs as f1anatic says, does not behave similarly.

Thanks, Russell
Take a look at this video, with emphasis on the Quadra Trac II equipped WK2.



When I first purchased the Jeep, I was expecting the Jeep's 4WD system to work more like (mechanical limited slip differentials) but actually it doesn't. It is the ABS involvement that creates this jerky behavior of crawl forward - brake the spinning wheel(s)- torque transfer along the same axle - crawl forward and ...repeat...

And if you look at , you will see that even Quadra Drive 2 equipped vehicles (rear E-LSD) suffer from the same "hopping" behavior when it comes to navigating over obstacles.
__________________
Reply With Quote
The Following User Says Thank You to f1anatic For This Useful Post:
  #12  
Old 12-29-2013, 05:00 PM
lt4vette's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: May 2013
Location: On a farm 200km north of Sydney Australia
Posts: 296
Thanks: 97
Thanked 13 Times in 12 Posts
Rep Power: 786
lt4vette is on a distinguished road
Re: 4WD behaviour

Quote:
Originally Posted by crabman View Post
I find the vehicle is smoother from a stop with eco turned off. It isn't just the trans shift points but also the throttle map that is altered in eco and I think it ends up being a bad combo. You get the eco trying to use less fuel until your commanded throttle input reaches a set point where it has been programmed to decide you want to move out smartly and then it ups the ante significantly to give it to you. Combined with a turbo diesel that is highly dependent on boost for power and you get a turbo that is just spooling up combined with a sudden large increase in fueling and bang, there is your surge. With eco off it acts like other diesels I've had where there is still a slight hesitation that you get around by giving it a little throttle to get rpm (and boost) up followed with a more substantial jab on the loud pedal which then moves you out smoothly but quickly. After a time you do this without even thinking about it and don't even notice it. Ive gone to switching out of eco as soon as the vehicle is slightly warmed up and I stay out of it till I'm on more open roads.
I'll try it with Eco off - thanks Crabman. I did do a bit more careful observation (eco ON) and noted that it is at 1800 - 2000 rpm that the surge starts, so I'll compare this with eco off.
__________________

__________________
2014 JGC Overland Cherry Red Off Road Adventure Package, ARB colour coded bar, 265/65/18 BFG's
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hydraulic Fan Behaviour chudsy Troubleshooting/Problems 6 10-23-2013 09:12 AM
Moving to FL, do i really need 4wd ? mrmotoguzzi00 Grand Cherokee - WK 16 09-15-2013 01:51 AM
4WD Help??? Zetzsche248 Grand Cherokee - WJ 1 04-16-2013 07:05 AM
Trouble getting it into 4WD RJ'sWJ Grand Cherokee - WJ 2 03-20-2013 06:59 PM
4wd system cherokee619 Grand Cherokee - WK 14 05-25-2011 04:12 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:47 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community