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Posted: Mon Jan 13, 2014 10:26 am
by cyanide
There are cars that can switch on the fly B/W 4H and 4L for instance infinti QX4 my friend used to have one I think...

Posted: Mon Jan 13, 2014 11:08 am
by Adnan
caprihorse;32097 wrote:This is required for specific models, mostly equipped with automatic transmission.
All models equipped with manual transmission don't need to have main gear in neutral, just car needs to be stopped, not moving at all.
Thank you friends for such fruitful discussion and valuable input in this regard, however, in sake of feeding this subject more, I would put the following situation to your analysis and opinions:
As clearly stated above that shifting from 4H to 4L needs fully stopping or semi stoppage of the car, so what about if while driving you surprised with huge drop (like Liwa's one) while you are driving on 4H and quickly need to shift 4L to help engine break and transmission control on car's speed,noting in your mind that any stoppage on such slop to shift the gear means 90% rollover ?

Posted: Mon Jan 13, 2014 11:28 am
by caprihorse
[quote=cyanide;32192]There are cars that can switch on the fly B/W 4H and 4L for instance infinti QX4 my friend used to have one I think...[/quote]
QX4 is same as Pathfinder, just upholstery is different. Definitely you must stop the car when switching to 4L. On the fly you can switch between 2H and 4H up to speed 80km/h.

Posted: Mon Jan 13, 2014 11:29 am
by strawb
Adnan;32193 wrote:Thank you friends for such fruitful discussion and valuable input in this regard, however, in sake of feeding this subject more, I would put the following situation to your analysis and opinions:
As clearly stated above that shifting from 4H to 4L needs fully stopping or semi stoppage of the car, so what about if while driving you surprised with huge drop (like Liwa's one) while you are driving on 4H and quickly need to shift 4L to help engine break and transmission control on car's speed,noting in your mind that any stoppage on such slop to shift the gear means 90% rollover ?
The same happened to me in Liwa after the first suprise drop wherein i was on 4H and 2nd gear .......

i pulled on the handbrake and controlled the steering and throttle to a comfortable and controllable speed ......

this usually happens if you were the lead car in the convoy though ...... the rest of the convoy has the comfort of being pre-warned about the drop

Posted: Mon Jan 13, 2014 12:12 pm
by lizzy
Here's a car that can do it on the 'fly'. I'll let you work out which one it is:

[ATTACH=CONFIG]1752[/ATTACH]

Posted: Mon Jan 13, 2014 8:00 pm
by Adnan
strawb;32197 wrote:The same happened to me in Liwa after the first suprise drop wherein i was on 4H and 2nd gear .......

i pulled on the handbrake and controlled the steering and throttle to a comfortable and controllable speed ......

this usually happens if you were the lead car in the convoy though ...... the rest of the convoy has the comfort of being pre-warned about the drop
well said Strawb bro, my point of view that the ideal circumstances of shifting the gear are NOT available in some special cases, hence you did your own procedures to handle this steep slope and controlled your car ( thank God you h'vnt fish tailing ) due to your initial speed at that time,

however, practicing different steps and driving criterial features based on the current situation is MUST when stopping the car is not possible to avoid any rollover May mishap .

Posted: Tue Jan 14, 2014 9:25 am
by caprihorse
Adnan;32193 wrote:Thank you friends for such fruitful discussion and valuable input in this regard, however, in sake of feeding this subject more, I would put the following situation to your analysis and opinions:
As clearly stated above that shifting from 4H to 4L needs fully stopping or semi stoppage of the car, so what about if while driving you surprised with huge drop (like Liwa's one) while you are driving on 4H and quickly need to shift 4L to help engine break and transmission control on car's speed,noting in your mind that any stoppage on such slop to shift the gear means 90% rollover ?
To switch to 4L is not a must, it is just safety precaution. As leading, or solo driving car, you are always watching the terrain and expecting surprises. In anticipation of bad surprise we use to stop (in Liwa) and observe terrain, we never drive wildly.
If you cannot stop for some reason, you just switch to the lowest gear and drive down as safely as possible, controlling car turns with steering, throttle and soft braking. Playing with hand brake helps also to slow down the speed and controlling straight position.

Posted: Tue Jan 14, 2014 11:36 am
by Adnan
caprihorse;32228 wrote:To switch to 4L is not a must, it is just safety precaution. As leading, or solo driving car, you are always watching the terrain and expecting surprises. In anticipation of bad surprise we use to stop (in Liwa) and observe terrain, we never drive wildly.
If you cannot stop for some reason, you just switch to the lowest gear and drive down as safely as possible, controlling car turns with steering, throttle and soft braking. Playing with hand brake helps also to slow down the speed and controlling straight position.
Exactly Boss, that is my point that shifting to 4L is not a must when its not possible ( quote :[INDENT] practicing different steps..... )[/INDENT]

but you can carry out another steps like you well said to control your car while it slopped down safely.

Posted: Tue Jan 14, 2014 12:10 pm
by lizzy
Another factor to consider on long slip faces is whether your automatic transmission will shift up automatically when a certain rpm is reached. This is usually the case in high range and may result in you descending too fast, then using the foot brake and losing control. The point about using the handbrake in this scenario is spot on; the handbrake acts as a drag on the rear rather than using the foot brake which causes all wheels to brake. If you are able to manually select a gear on your automatic transmission, then there is less of a danger.

In low range some automatic gearboxes will not shift up if you’re able to manually put the gear lever into 4th, 3rd, 2nd or 1st gear. This makes it much safer for long descents because the gear will be held and the effects of engine braking are also greater.