New Differential or Rear End for heavy snow in 2wd

[MikeG]

Don't misunderstand me. Not looking for absolute "proof" one way or the other, trying to quantify it. Going uphill in snow is going to be a complex system with many variables..... WHICH variable is the most significant, and so on. And the answer to that is going to change based on the angle of the hill, vehicle mass, depth of snow, tire size, tread compound, air pressure, speed, weight distribution of the wheels, snow density, and maybe most important of all, the driver's right foot Etc., etc.

There is not much "proving" anything with 10 or more variables. However they can be ranked, in certain situations.

I actually do see some scenarios where it could make a difference. But, my conclusion is - it would have to be right at the limit of traction in the available conditions to make the difference between success and failure. There are some conditions for which it won't be needed, and some for which it cannot help.

I mocked up one scenario just based on random variables (ie. hill angle) and found some interesting (to me) data where someone attempted to measure rolling resistance, etc. Probably someone's thesis.

Entirely different proposition than looking at a design defect..... "oops, maybe we shouldn't have put the gas tank where it can be hit."

I thought it was an interesting exercise, but not everyone likes to dig through the numbers.

Anyway 3 flakes of snow on the road, and you're taking your life into your hands where I live, because people either drive three miles an hour, or twice the posted limit.... sometimes in the same lane, at the same time. So I will probably not ever get an opportunity to test it.

 

[Bracket racer]

IMO, a trac-loc(Ford brand) limited slip will help and you can swap out the whole axle so its just wrench work
3.73 or 4.10 would be fine with 30" tires, 4.10 might be a bit better if available

Limited slip just means if one wheel starts to spin faster than the other some of the power from that wheel is transferred to the other wheel
If both wheels have limited traction then both spin
So you will most likely still have to "chain-up" if traction in both sides/tracks of the road is poor

The benefit of 4WD, AND FWD, is that its much easier to PULL a weight up a hill that to push it, that's just the Laws of Physics
All factory 4WDs have an OPEN differential up front, as do FWD, it's just that PULL factor that makes either better
I.E. many with RWD will be able to reverse up a hill that they couldn't get up going forward, pulling the vehicle up the hill vs trying to push it up
Not an arguable point its just Physics

You certainly will be able to go farther with Limited slip, traction will decide how far that is

Sorry Ron, this is 100% wrong, period. If you lose the rear driveshaft in a 4x4 you can back up a hill using the front tires to push you as the weight is on them, the truck WILL NOT drive up using the front tires to pull it. If you have any doubts try it before saying I’m wrong. Vw’s were great in snow because the weight was over the drive tires and they were pushing, bugs would not back up hill at all.
Fwd cars also have the weight over the drive tires which helps them but again(and I’ve proved this to numerous people living in the snow belt in Canada) if you can’t get up a hill in a fwd car, back up it! All the weight is on the tires as opposed to unloading the drive tires as you go up hill.
If anyone is serious about snow driving, dedicated winter tires and studs. If that won’t get you were you’re going and you need chains, then you are at the “serious snow wheeling” stage.
I’ve done recovery for 36 years and have driven vehicles out of spots people were stuck in and were convinced needed a winch.

 

[RonD]

Actually is not wrong

I think you are basing everything on traction, weight of engine on drive wheels as an example, or weight shift, i.e. driving FWD vehicle backwards up a hill shifts more weight onto the now downhill drive wheels for better traction
While traction IS most of the equation its not all of the equation

When you are stuck in the snow(and other things, lol), why in the world would you dig out the snow in front of or behind the wheels?
You don't get more traction with that?
Is that done to get some momentum to get up and over the obstacle, out of the hole?
Or "rocking" the vehicle, move forward and then reverse, back and forth to get momentum to get up and over the obstacle, out of the hole?

Having the drive wheels in front helps prevent the obstacle from building up too high and slowing your momentum
Its certainly not the be all end all, just worth a try
Same as using the parking brake with open rear differential "might" get you unstuck if the "other wheel" has more traction, and in this case it is all traction, lol

We can agree to disagree

 

[MikeG]

You get less resistance, not more traction by moving the snow, mud, sand, whatever. Small correction.

I agree with Ron here, there is force needed to move the snow out from in front of the wheels (or squash it down or whatever). The only question in my mind was, "how much" and under what circumstances would it make a difference.

 

[Curious Hound]

@RonD , @MikeG, @Bracket racer ,

Y'all are funny. While the three of you calculate and debate all winter, remember. The rest of us are out having fun driving and getting stuck and unstuck and driving some more.

 

[MikeG]

Way too dangerous for me to drive in the stuff around here!!!!!

 

[Bracket racer]

we’ll agree to disagree then. I’ve blown driveshafts off and had to drive with just the front pulling and broke axles and had to drive with just the rear, going uphill you want weight transfer onto the drive wheels regardless of whether they are fwd or rwd. I drive with the hubs unlocked until I either get stuck or come upon a “holy crap” hole. I’ve blown the rear shaft off and to get home with just the front pulling I had to turn around and back up the hill, it would NOT pull itself up a steep hill with all the weight transferred to the rear. As far as the amount of snow building in front of a tire (or the diff or the air dam) you can say e=mc2 all you want, in the real world you want momentum to get you up a hill and as you crest or if it starts spinning you keep easing up on the throttle to keep traction. If you have to go slow then traction is only thing that will get you up. The amount of traction gained by having the vehicle weight transferred onto the drive wheels is exponentially greater than the amount of reduction you would get by the tire trying to drive over the snow instead of push through it. It’s not even close. If anyone wants proof of what works, winters coming, unlock your hubs and try and back up a hill and then turn around and try to drive up it. Heck, find a muddy hill tonight, do the same thing, stop at the bottom and see which way it will go up and which way it won’t.
Best thing in winter is dedicated winter tires with studs and momentum. In that order.