Center Differential?

[toddjb122]

I think the moral of the story is that if you are going to use your truck as a snowplow, put it in access mode first.

David

That's actually not an awful idea. Or more likely, I'd motor into the deep snow parking spot in any height, but then move it down to normal or access to pack it down over night when things will firm up anyway. Then when I move the car in the morning...raise to offroad height and off you go!

You could also actually shovel a parking spot, but what fun is that!

 

[davez26]

I almost forgot about my original question - does anyone know if the center diff will lock in reverse?

Thanks,
Rich

GTR doesn't say specifically, but from the theory of operation and in the field use, I'd say yes, it does lock in reverse.
Rich, I did a similar thing in the free lot one street East of Main Street in Breckenridge. I ended up parking on a pretty big snow pile, and the BFG's dug through the snow layer down to the ice and high centered it , with the same problem. Stupid laws of physics!
Wordy GTR stuff below:
The DD295 transfer box is a full time, permanent four-wheel-drive unit, with 50/50 torque distribution to the front and rear driveshafts. The unit is manufactured by Magna Steyr Powertrain in Graz, Austria and supports the following features:
Permanent four-wheel-drive with a bevel gear centre differential, providing a 50:50 torque split
Selectable high and low range for optimum on-road and off-road performance
Two-speed, fully synchronized 'shift-on-the-move' system allows the driver to change the range without having to stop the vehicle
Electronically controlled multi-plate clutch providing a centre differential lock and torque biasing function to give improved traction performance and vehicle dynamic stability.
A strategy, to electronically control the centre differential multi plate clutch assembly, has been developed to provide:
a pre-loading function, increasing locking torque with increased driving torque
a slip controller to increase locking torque under off-road conditions and decrease locking torque for optimum comfort, e.g. parking.
The unit is located under the vehicle and is mounted on the cross-member, behind the transmission. The unit is identical for all engine derivatives.
The transfer box receives a torque input from the transmission output shaft, which is passed through the unit to two outputs for the front and rear drive shafts.
The input torque is equally distributed via a bevel gear type differential. In order to provide an optimal torque distribution to each wheel in all driving conditions, the unit is equipped with an electronically controlled locking and torque-biasing device. This device detects wheel slip via various vehicle system inputs to the transfer box control module and locks the differential accordingly. The locking torque is applied through a multi-plate clutch assembly.
A planetary gear set, located in the differential assembly, allows the driver to select high or low range whilst driving, this is known as 'shift on the move'. When in low range, the planetary gear set provides a ratio of 2.93:1, which gives the vehicle an extremely low crawl speed for off road driving and trailer towing. High range is a direct drive from the transmission output shaft and provides a 1:1 ratio.
Both the centre differential locking and biasing and the 'shift on the move' features are actuated via a DC transfer box motor, which is controlled by the transfer box control module, via a Pulse Width Modulation (PWM) signal.

 

[Houm_WA]

I'm sure the CDL works in reverse.

I've done enough stuff in my LR3 at this point to assure you that it is every bit the off-road machine that it is billed as.

...but there is always something to learn as a driver.

 

[richpike]

GTR doesn't say specifically, but from the theory of operation and in the field use, I'd say yes, it does lock in reverse.
Rich, I did a similar thing in the free lot one street East of Main Street in Breckenridge. I ended up parking on a pretty big snow pile, and the BFG's dug through the snow layer down to the ice and high centered it , with the same problem. Stupid laws of physics!

Thanks Dave - it makes me feel better to know that someone like you had a similar issue.

BTW - I know it is a ways out, but I'll definitely be attending the trip to the Great Sand Dunes. I'm assuming we are doing Medano Pass? I've been reading up on it a bit and it looks like a fun trip (especially that time of year - I bet there will be some fantastic water crossings with all the snow melt).

-Rich

 

[PaulLR3]

Rich, part of your problem was the tires. I ran Pirelli Scorpion Ice & Snow winter tires on our Q7 last winter and they were great in all conditions. I put a set of Grabber AT2's on the same 18" wheels for beach driving this past summer. I figured I would skip doing another changeover and use the Grabbers this winter as well. They do not work well on ice at all. A recent storm was heavy rain followed by a foot of very wet snow. I got our Q7 stuck in the driveway and had to dig it out. For fun, I tried my A4 which also got stuck but I was able to spin the tires to the point of melting the base layer of ice and got out without digging. I think the Grabber tread compound is too hard and all those tiny sipes you see on winter tires are missing. I bet you could have gotten out if you had true winter tires.