Using a low-range gearbox in snow

laissez-faire

laissez-faire

laissez-faire

Soldato
Joined
23 Oct 2002
Posts
2,562
Location
Edinburgh/Southampton
The only time I have ever driven in really deep snow was in scotland. I spun around a few times (mostly on purpose) but the only time I got stuck in my FWD golf was going up a hill. Wouldn't go up in 1st gear at all, nor 2nd, but when I put it in 3rd I just slowly lifted the clutch and up she went.

What's the physics behind this? In 3rd gear surely the wheels would be trying to spin faster, so why don't they just slip even more? I am guessing it's something to do with the differential and the fact that trying to pull off in 3rd gear there's very little torque available to apply to the wheels?

So - if you have a low-range gearbox, then the ratios in that will be even LOWER than 1st/2nd, so in snow would you just use a high-ratio box? Or is the low-ratio box usually clever enough to limit torque?
 
The higher the gear, the lower the torque multiplication effect as you say. This means that even relatively large throttle movements don't suddenly apply lots of torque to the wheels, which is what starts the wheels spinning in the first place, i.e it lowers the wheel torque, and gives you finer control of what torque there is.
 
I use 2nd and 3rd in snow. I put it down to controlled traction, i.e. less chance of wheel spinning in a higher gear and thus less chance of breaking traction. My friend managed to park in a car park here on a slight hill, he was driving a 2.0lt Focus with TC and got in the car park where as almost everyone just slid straight back out lol
 
On my gearbox with "High range" i.e. that in my HGV, I use as tall a gear as possible in the snow, usually 6th or higher.

14 gears F.T.W. :D
 
So my real question then - do you need to use your low-range gearbox in the snow or not? Is it redundant apart from for climbing very steep inclines?
 
they don't in norway, you just use higher normal gears, as you would in any other car.

low range is for rough, muddy terrain, wading through water or hills
 
laissez-faire said:
So my real question then - do you need to use your low-range gearbox in the snow or not?
Click to expand...

Not really , no.

Speaking from the point of view of an HGV driver, low range is near useless in snow.

Yes, you need it to climb steep hills, but, if said hills were snow covered, chances are you won't get up it in low range anyway, the laws of physics combined with little or no traction see to that.

Trucks are ok in snow in high range, until you meet a hill that requires low range and then the fun starts!
 
Fresh snow is not driven quite the same as packed snow. But in either state you must aim to stop just short of breaking the traction. This is the main reason why torquey motors in low gears favour slippery conditions over equivalent but usually less torquey petrol motors.

The 3rd gear was working for you as everything literally teeters on the edge of both grip and stalling, and lo' you're into prime time traction territory.
 
Fido McNasty said:
This is the main reason why torquey motors in low gears favour slippery conditions over equivalent but usually less torquey petrol motors.
Click to expand...

So this explains me being able to pull away on a hill near Corbridge a few months back, despite thick settled snow on the road in 6th? but not 1'st, 2nd or 3rd, 4th etc - The clutch stank to high heaven mind you :o but the truck gripped eventually in 7th and away it went. :)

I had been playing about with the axle load transfer to also help traction, as soon as my "lift axle" raised, the truck was willing to grip & go, but, as it was pulling a lot of weight, the air suspension kept dropping it again, causing a loss of traction.

I've always assumed that the relatively high torque was a bad thing in lower gears with regard to traction issues? :confused:

FWIW, the TC light was blinking like it had gone nuts. :D

Confused a bit here, help us out bud. :)
 
What does setting off in 2nd/3rd (in snow) do to your clutch (in a car)?

It's not often we get snow, but like Long Distance Clara above (sorry I can't remember the name and I'm not scrolling up :)) my clutch stank somewhat.
 
Last edited:
Jono said:
What does setting off in 2nd/3rd (in snow) do to your clutch (in a car)?

It's not often we get snow, but like Long Distance Clara above (sorry I can't remember the name and I'm not scrolling up :)) my clutch stank somewhat.
Click to expand...

No significant damage other than the possibility of wheelspin. The purpose is not to slip the clutch any more excessively than usual but to let it out just as you do normally, not quite stalling the motor. Higher torque simply reduces the chance of stall at very low rpm's. Traction in slippery conditions comes of low but consistent rotation speeds. Even a moment of spin is quickly halted if a flywheel is spinning slowly enough.

Ice in itself isn't actually slippery. It is meltwater or meltwater surface molecules that give rise to slippery surfaces on ice and/or snow.
 
Fido McNasty said:
Ice in itself isn't actually slippery. It is meltwater or meltwater surface molecules that give rise to slippery surfaces on ice and/or snow.
Click to expand...

i beg to differ. ice is very slippery, add some water on top, then its ****ing slippery :D

driving on hard, packed snow is fine. it's almost like driving on tarmac. if it's -5 or lower on a snowy road that's been driven on for a while, it's quite pleasant driving conditions.

the worst is when it's fresh powder snow as the grooves fill up, and slush is unbelievably slippery too..

either way, low-range is useless in all of these conditions
 
You must log in or register to reply here.
Back
Top Bottom