Thread: Descent control question

I had a similar scare with mine. Steep incline, loose stones (marbles), failure to preceed moment. I used HDC and despite my inexperienced efforts the front still came around and almost rolled. In the excitement of the moment I forgot the golden rule - to accelerate to keep the car straight when needed.

After this incident I also went and fitted a CDL linkage. Haven't had a similar issue again thankfully. Oh, also remember there is also the 'drive through the brake' technique for really steep stuff in an automatic.

Originally Posted by XHPBT1

I once tried to climb up a very steep incline for about 400 meters it was all covered in small loose rocks, nearly got to the top when all 4 wheels were spinning in one spot, so then I put it in reverse and tried to slowly go back down, but what was happening was the front was trying to come around, which is awful on a steep incline, Hit the HDC let go of all breaks, left it in reverse and held the steering straight, it was unbelieveable as the HDC controlled the front from coming past which you could feel that it wanted to. It was trying all the way down, the breaks would just adjust and correct it so it remains stright the EBD was doing it's job and came down that hill safely and straight to my surprise. After tryig again but this time only went up alittle and tried to bring the d2 down without HDC it was nearly impossible to keep it straight on such a loose surface...

Just letting the car go, to let the HDC kick in, can be fraught with danger.
The HDC initially kicks in at 7mph, which is very fast in a slippery, reverse down hill situation.
With an auto, I believe you are better off inching backwards with the transmission in forward gear, using the brakes and handbrake as required. This way you can gun it forward to straighten her up if it gets sideways.
I learnt this the hard way when my mate rolled my car with me in it. He let the car roll backwards for the HDC to kick in, and when it did, it toppled over onto its side after hitting a small rut.
Having said this, I believe using HDC going forward is brilliant.
Cheers all.

Originally Posted by Zute

I didnt have the centre diff' locked and maybe there might be something in that. But I find it chugs down hill fine without HDC.

There is definitely something in that! I have a video from 1999 that shows this problem in a controlled environment. Reversing down a steep hill without CDL engaged is positively dangerous!!!!!!

Cheers,

Franz

Is that video online Franz? Or can it be?

Peter

Is that a certain lady who has a white D2 who convinced lr on the strength of that video to re-install cdl for her? I know about that. Don't use it in reverse without cdl engaged. Forward it seems to work very well with or without cdl but with if you have it. I can engage mine at 50'kph in high range. Very fast reduction from there! In low first in my v8 manual it comes on and brakes to well below 7kph even with 31's. Cheers

Originally Posted by ozscott

Is that a certain lady who has a white D2 who convinced lr on the strength of that video to re-install cdl for her? I know about that. Don't use it in reverse without cdl engaged. Forward it seems to work very well with or without cdl but with if you have it. I can engage mine at 50'kph in high range. Very fast reduction from there! In low first in my v8 manual it comes on and brakes to well below 7kph even with 31's. Cheers

Class action and free CDL levers for all?

Originally Posted by Zute

The other thing that can happen is it over heats
and shuts down ie releases the brakes. Better not to use it.

It calculates when the brakes might start to overheat considering the extent of usage, speed etc. There are no temperature sensors.