Member Since: 24 Dec 2010
Location: Borders
Posts: 11027
Creeping backwards in "Drive"
Experienced it yesterday after I stopped on a hill to talk to someone out the window.
Took the foot off the brake to pull away,and the car started slowly edging backwards with the gearbox in Drive
Put it into Park,and tried it again....same thing....
Technically,and mechanically, that's not possible....right ?"Better to remain silent and be thought a fool,than to speak out and remove all doubt" ?.....what rubbish...
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10th Apr 2016 7:58 am
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20733
Member Since: 24 Dec 2010
Location: Borders
Posts: 11027
I certainly didn't think it would have been steep enough to get the car creeping backwards.....anyway I assumed an auto box with a forward gear engaged wouldn't/couldn't creep back....you're saying under certain circumstances it can"Better to remain silent and be thought a fool,than to speak out and remove all doubt" ?.....what rubbish...
Locking rear E-diff
RLD spare wheel protector & sump guard
Extended roof rails
Series 111 mudflaps
Black side tubes,grill and vents
Timed climate remote
Hids4u interior lights
D4 Firenze my2012 HSE
D3 Java 2005 SE manual (sold,sadly,thanks for the memories)
1966 '88 Series 2a....still starts in the morning better than I do...
10th Apr 2016 8:10 am
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20733
Never experienced it in an 8speed box, but I can get my 6speed to roll back on a steep enough hillMy D3 Build Thread
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50947
It shouldn't do it in Park
On the 8 speed it will do it in drive after 3 or 4 seconds of intended "hold" .... gravity will take over 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
10th Apr 2016 9:08 am
Dave T
Member Since: 03 Jul 2009
Location: Glasgow
Posts: 6902
Think it's time for a new one Euan..... Joined the BMWX5 45e group
1994 Defender 90
2015 RRS Corris Grey/Black roof
2016 D4 Graphite Santorini Black
2012 D4 XS Orkney Grey
2005 D3 S Maya Gold
Convoy for Heroes 2011
10th Apr 2016 9:12 am
Fitzy73
Member Since: 09 Feb 2014
Location: Truro
Posts: 2407
My 6 speed rolls backwards when in drive, especially on my in-laws drive which is very steep and requires care.Andy
10th Apr 2016 9:14 am
Dave T
Member Since: 03 Jul 2009
Location: Glasgow
Posts: 6902
From the manual (2016 version)
GRADIENT RELEASE CONTROL (GRC)
Gradient Release Control (GRC) operates when the vehicle is pulling away from standstill on an incline, or a decline. When the vehicle's brakes are released, GRC automatically delays and graduates the brake release to allow the vehicle to pull away smoothly.
GRC automatically operates in forward and reverse gears. No driver intervention is required.Joined the BMWX5 45e group
1994 Defender 90
2015 RRS Corris Grey/Black roof
2016 D4 Graphite Santorini Black
2012 D4 XS Orkney Grey
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10th Apr 2016 9:21 am
euangibson
Member Since: 24 Dec 2010
Location: Borders
Posts: 11027
Thanks all
DG...yes Park held it as expected,it was just the creeping backwards in Drive that threw me.....
Dave...... just checked my manual and there is no mention of GRC....maybe they thought they should mention it in later manuals for idiots that have my2012..... "Better to remain silent and be thought a fool,than to speak out and remove all doubt" ?.....what rubbish...
Locking rear E-diff
RLD spare wheel protector & sump guard
Extended roof rails
Series 111 mudflaps
Black side tubes,grill and vents
Timed climate remote
Hids4u interior lights
D4 Firenze my2012 HSE
D3 Java 2005 SE manual (sold,sadly,thanks for the memories)
1966 '88 Series 2a....still starts in the morning better than I do...
10th Apr 2016 9:36 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
The gearbox itself is more than capable of rolling backwards on a hill, but if you have stopped and have remained on the foot brake with sufficient pressure then it should not roll backwards; the system should still be applying hydraulic pressure even when you remove your foot. Depending on what you do with your feet you can fool/overcome the system though and it will then behave like a regular automatic (eg a D3).
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
Perfectly possible for any automatic to roll backwards when in drive at idle. If the amount of torque produced at idle is less than that required to hold it on the incline then it will roll backwards (without other intervention from things like GRC obviously).
The D4 GRC is a hit and miss thing in my experience. If you are completely stationary on the slope with foot on the brake and then go straight to the throttle it works quite well. But if you go to the throttle a touch and then change your mind and release the throttle without going back to the brake, the engine falls to idle and the car rolls backwards - the brakes are not reapplied once you have touched the throttle until you sit there with your foot on the brake again.
10th Apr 2016 5:12 pm
Dave T
Member Since: 03 Jul 2009
Location: Glasgow
Posts: 6902
But surely that's what it is designed to do.... "When the brakes are released it delays and graduates the brake release", it won't reapply them if you change your mind.Joined the BMWX5 45e group
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2015 RRS Corris Grey/Black roof
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Convoy for Heroes 2011
10th Apr 2016 5:36 pm
discoteca
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
Indeed. I was just making the point that GRC or not, it is still possible in many scenarios for the car to roll backwards in drive.
10th Apr 2016 5:43 pm
DG Site Moderator
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50947
But GRC is doing what it should do i.e hold the brakes on for a few seconds ...if you decide to release then touch the throttle then change your mind ... that is not the fault of the system 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
10th Apr 2016 5:48 pm
discoteca
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
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