Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 -

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #205  
Old 02-22-2014, 09:46 AM
Member
 
Join Date: May 2012
Posts: 97
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 1057
overlanding is on a distinguished road
Quote:
Originally Posted by Milous View Post
ALWAYS use your parking brake!!!
Uh ok because that's a Grand Cherokee?
__________________

__________________
Reply With Quote
  #206  
Old 02-23-2014, 07:53 AM
Member
 
Join Date: Jan 2014
Posts: 91
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 443
ADGrant is on a distinguished road
Quote:
Originally Posted by overlanding View Post
Uh ok because that's a Grand Cherokee?
I hope so.
__________________

__________________
Reply With Quote
  #207  
Old 03-09-2014, 12:14 PM
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jul 2013
Location: Hurricane, WV
Posts: 53
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 564
GoHerd is on a distinguished road
Re: Holy smacks! My JGC just moved itself out of the driveway

Well it snowed again last week and I was able to get my JGC to replicate the rolling while in park scenario again and again.

This time I've recorded it while it happened and also had my wife do it from the outside so you could see what the wheels are doing when it's rolling. I believe that user tomk nailed it in this other thread:

2014 Jeep grand cherokee summit rolls in park

It would seem the video confirms that the open differential allows the Jeep to roll when one wheel does not have traction. It shows the rear tire spinning forward while the front one rolls backward. Dealer was still amazed when I showed them the video. "Crazy" seemed to be the predominant term from sales to finance to service.

So here's the videos:

Jeep a Rollin in park on Vimeo

Jeep a Rollin in park 2 on Vimeo

Incidentally, I got rid of my 2014 JGC on Wednesday.

I traded it on a 2014 JGC CRD. ;-)

I bet it rolls in park, too.
__________________
Reply With Quote
  #208  
Old 03-09-2014, 01:00 PM
Premium Member
 
Join Date: Sep 2013
Posts: 575
Thanks: 2
Thanked 68 Times in 51 Posts
Rep Power: 6357
Peter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond repute
Yeah, you're definitely sliding in those videos, not "rolling" so to speak.
__________________
Reply With Quote
  #209  
Old 03-09-2014, 01:14 PM
Kjens2004's Avatar
Member
My Jeep: 2014 5.7L WK2
 
Join Date: May 2013
Location: Houston, tx
Posts: 73
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 669
Kjens2004 is on a distinguished road
Garage
Looked like back tire was sliding, really turned the opposite direction a little bit, but the fronts looked like they were rolling freely. I wonder if you park it while in 4 lo would hold the front axle too?
__________________
Reply With Quote
  #210  
Old 03-09-2014, 02:50 PM
Premium Member
 
Join Date: Sep 2013
Posts: 575
Thanks: 2
Thanked 68 Times in 51 Posts
Rep Power: 6357
Peter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond repute
Quote:
Originally Posted by Kjens2004 View Post
Looked like back tire was sliding, really turned the opposite direction a little bit, but the fronts looked like they were rolling freely. I wonder if you park it while in 4 lo would hold the front axle too?
The fronts will never be held. The transfer case uses an electronically modulated wet clutch pack which I believe is disengaged when the vehicle is off. I don't believe 4Lo locks the front and rear together by default.
__________________
Reply With Quote
  #211  
Old 03-09-2014, 02:57 PM
Kjens2004's Avatar
Member
My Jeep: 2014 5.7L WK2
 
Join Date: May 2013
Location: Houston, tx
Posts: 73
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 669
Kjens2004 is on a distinguished road
Garage
In 4 hi I know its all electronic. I was just remembering a post from the thread about being stuck in sand when 4x4 malfunction. Some one posted that even with the evic showing the error, because the transfer case locks in low range he still had 4 wheel drive when he went to low range. I know this is different cause the jeep is not running. Just a thought.
__________________
Reply With Quote
  #212  
Old 03-09-2014, 08:06 PM
SW03ES's Avatar
Senior Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jun 2011
Location: Gaithersburg, MD
Posts: 1,853
Thanks: 17
Thanked 61 Times in 49 Posts
Rep Power: 1303578
SW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond repute
Re: Holy smacks! My JGC just moved itself out of the driveway

Its definitely sliding down the driveway, not rolling. I think it would probably do that even with your parking brake applied. You can see the rear wheel staying stationary mostly, and out the door in your first video you can see it on the other side as well. The service brake holds all 4 wheels, but the parking brake doesn't.

Thats just a weird combination of your driveway, and snow, and the Jeep.

As Peter said, the fronts will always rolls freely. All the parking pawl does is stop the drivetrain from rotating. Wheels not connected to the drivetrain will roll.
__________________
~Steve~
2014 Jeep Grand Cherokee Overland V6 4X4. Maximum Steel w/ Vesuvio Jeep Brown/Indigo Blue. Advanced Tech Pkg.
2013 Lexus GS350 AWD, Liquid Platinum w/ Flaxen. Luxury & Cold Weather Pkg
Previous Jeep: 2011 Grand Cherokee Laredo X w/Nav, QT1 & Trailer Tow
Reply With Quote
  #213  
Old 03-09-2014, 08:15 PM
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jul 2013
Location: Hurricane, WV
Posts: 53
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 564
GoHerd is on a distinguished road
I understand at least partially here. But it did not slide at all when my foot was pressing the footbrake or when I engaged the parking brake.

Quote:
Originally Posted by SW03ES View Post
Its definitely sliding down the driveway, not rolling. I think it would probably do that even with your parking brake applied. You can see the rear wheel staying stationary mostly, and out the door in your first video you can see it on the other side as well. The service brake holds all 4 wheels, but the parking brake doesn't. Thats just a weird combination of your driveway, and snow, and the Jeep. As Peter said, the fronts will always rolls freely. All the parking pawl does is stop the drivetrain from rotating. Wheels not connected to the drivetrain will roll.
__________________
Reply With Quote
  #214  
Old 03-09-2014, 08:54 PM
SW03ES's Avatar
Senior Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jun 2011
Location: Gaithersburg, MD
Posts: 1,853
Thanks: 17
Thanked 61 Times in 49 Posts
Rep Power: 1303578
SW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond reputeSW03ES has a reputation beyond repute
Re: Holy smacks! My JGC just moved itself out of the driveway

Quote:
Originally Posted by GoHerd View Post
I understand at least partially here. But it did not slide at all when my foot was pressing the footbrake or when I engaged the parking brake.
Thats why you should always use the parking brake

Its not the car's fault that it slides down an ice/snow covered driveway.
__________________
~Steve~
2014 Jeep Grand Cherokee Overland V6 4X4. Maximum Steel w/ Vesuvio Jeep Brown/Indigo Blue. Advanced Tech Pkg.
2013 Lexus GS350 AWD, Liquid Platinum w/ Flaxen. Luxury & Cold Weather Pkg
Previous Jeep: 2011 Grand Cherokee Laredo X w/Nav, QT1 & Trailer Tow
Reply With Quote
  #215  
Old 03-09-2014, 09:10 PM
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jul 2013
Location: Hurricane, WV
Posts: 53
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 564
GoHerd is on a distinguished road
Quote:
Originally Posted by SW03ES View Post
Thats why you should always use the parking brake Its not the car's fault that it slides down an ice/snow covered driveway.
My Jetta didn't do it. Dealer also was puzzled.
__________________
Reply With Quote
  #216  
Old 03-09-2014, 09:14 PM
Premium Member
 
Join Date: Sep 2013
Posts: 575
Thanks: 2
Thanked 68 Times in 51 Posts
Rep Power: 6357
Peter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond reputePeter_K has a reputation beyond repute
Quote:
Originally Posted by GoHerd View Post
My Jetta didn't do it. Dealer also was puzzled.
BIG weight difference. Heavier vehicles will tend to form a water sheet with re-freezing directly under the tires. The pressure differential alone can create this effect. Plus, with a heavier vehicle you have more rearward pressure on the slope as well.

This really looks like a combination of:

1) front wheels free to turn

2) parking pawl is locking the transmission, and thus the rear driveline

3) rear differential is open. Look at the exterior video--one rear wheel tries to go FORWARD as well as sliding. This is exactly how an open diff with a locked driveline will behave when the other wheel tries to move in the reverse direction.

The parking pawl seems to be working.
__________________

__________________
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
New Mopar in the driveway..... Scottina06 Other Rides 4 05-26-2013 10:13 PM
Jeep is in the driveway! Tonz0Fun23 Grand Cherokee - WK 25 05-20-2011 11:05 PM
600+ HP in my driveway Knightrider03m Other Rides 6 02-16-2011 08:09 PM
New addition to my driveway! XXX007 Other Rides 31 07-16-2009 09:48 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 05:02 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

JeepGarage.org is in no way associated with or endorsed by Chrysler Group LLC.