What 4wd mode should I be In for snow?

Hey guys. Got a 2015 Tacoma 4x4 off road. Go to snow here and there. Usually if there is snow on the road, I’ll be in 4hi.

but what about the areas where it’s snow——no snow——snow——no snow?

do you guys just keep it in 4x4 or switch back and forth?

as I understand, our trucks have a center diff, or transfer case that sends power 50-50 locked. So can’t drive with it on a dry surface when it’s dry. I don’t want to put extra stress on the drivetrain.

what are you guys doing? Is it ok to leave it in 4x4?



pictures from my recent trip where snow was off and on.

 

If its the corners you're worried about, highways are usually straight enough to where it's not a big concern

 

If I was driving that I would be switching back & forth between 2HI and 4HI, on the fly, as needed. Assuming your truck is in normal working order, this should be fine at any speed up to 60MPH. Best to do the transitions when the truck is travelling straight, not around curves.

In my experience, the truck can tolerate small accumulations of drive-line bind-up caused by differing wheel speeds around turns, on non-slipping surfaces (i.e. dry, or even wet/rainy, pavement) -- but only small accumulations.

The key is not how far you travel in 4HI on dry pavement -- essentially any distance in a straight line is fine. It's the turns. If I am in 4HI during heavy rains on asphalt roadways, I will switch out of 4HI and back to 2HI after completeing no more than a few -- maybe 2 or 3 -- major curves in the road.

I can drive for miles in a straight line at highway speeds, in 4HI, and barely perceive any sound or sensation when switching back to 2HI. But after just a few curves at the same speeds in 4HI, there is a distinct "clunk" and shudder when switching back to 2HI. The clunk/shudder is driveline windup / tension being released.

I'm very cautious & attentive when using 4HI this way. I would not want to find out what the upper limits of driveline windup are when travelling at highway speeds. Seems like it'd be possible end up in a situation where extreme windup makes it impossible to switch out of 4HI.

Here are some further thoughts I've shared about driving in 4HI on dry pavement.

 

4HI both photos. It is intended for low traction. Use it for stability and be safe.

I dial it off when the pavement is dry, but wet and Icey means twitchy rear end. Especially with non-winters.

The biggest wear point is the front u joints, they are the weak point, and they are 40$ each. The tcase and diff can handle it. It's a Toyota.

 

I do sometimes shift in and out. BUT often the change can come fast and sometimes I’m above 60. I think you are fine leaving it in 4hi. There is a lot of stress out on these systems when people are rock crawling and the trucks handle it. Just minimize it as you can and don’t sweat it too much

 

In pics posted, leave it on.

Lol, it's friday

 

if its "snow, no snow" then it's probably not slippery enough to desperately need 4x4 in the first place

 

That is why I used a 4runner transfer case on my 4X4 conversion. You can select lock or unlock mode.

 

Just wanted to say:
No center diff in Tacomas as that would allow different speeds on wheels or as some call "auto" or "autotrac" for all pavements.
This is one area where Toyota has been lacking.

 

Mountain highways are anything but straight…or flat.

Pretty sure the landcruiser used an actual center diff back when suvs didn’t have air bags.
It’s lacking because they don’t really make any other awd with low range 4x4s

 

Really depends on your level of experience driving in such conditions and how well you know your vehicle. In those two pictures you posted, I would feel more then confident driving in 2wd

 

I use 4X4 as needed. Over half of the vehicles on the road don't even have 4X4 and they are getting along just fine. If you need help getting moving, especially on an incline, it only takes a second to flip the switch. Once on level ground 4X4 isn't helping that much. The bigger problem is stopping and 4X4 doesn't help that at all.

If the snow is 4-6" or deeper everywhere then leaving it in 4X4 all the time won't hurt and if you feel better then leave it in 4X4 all the time. With light or patchy snow I don't do that. I flip back and forth as needed. If you choose to just leave it in 4X4 on surfaces where there is no snow you probably won't break anything, for now. But you are over stressing components that will eventually fail sooner than they should.

 

I switch in and out of 4WD, but am not too worried if I hit a little wet pavement before I do.

 

I'll correct this (again) only because it's so widely misunderstood. You have a traditional part-time transfer case with no center diff. A center diff is an add-on to a traditional transfer case. A traditional transfer case is functionally the same as a locked diff but it simply mates the two outputs together through a direct drive using a chain or gear set.

In this configuration the transfer case does NOT send power 50/50, nor does it send torque 50/50. What it does do is send equal speeds F/R and biases torque output F/R from 0/100 to 100/0 and anywhere inbetween. The power output is just the torque each axle receives multiplied by the rotational velocity (speed).

On snow or partial snow roads leaving it in 4HI is fine. You will know when it binds as you can feel it. Bind increases with tighter turns at slower speeds and as traction levels go up. Pay attention, turn off 4HI when on higher traction surfaces turning tightly and you'll be fine.

 

4wd isnt going to help in any of those situations unless its steep enough to need the extra traction to keep you moving forward.

due to the lack of a center diff you could actually start pushing in corners. Id personally be in 2hi till its needed to get me moving forward.

 

The problem is if the rear loses traction it spins rapidly at a different speed than the front and you are more likely to spin out. This is the most common thing to happen at highway speeds in trucks on ice.

If you lock front and rear it won’t induce understeer on low traction. I have no idea why so many people on here think 4x4 is crazy to use at highway speeds on low traction.

 

Seriously, that how guys end up in the ditch

Unless you've got hundreds of lbs of sand in the bed and sticky snow tires, lock that shit in and forget about it. If it's binding you'll feel it, cycle it off and back on, keep driving

 

As someone from the north who drives in the snow a lot, my technique for when to use 4x4 is any time there is snow covering the pavement or the instant the truck squirms around on the road turn 4hi on and leave it on.
The problem with turning it off and on is when you need it you need odds are you need it faster than you can switch it back on.

I have done thousands of miles driving in snow/icy conditions leaving 4hi on all the time and never had anything break.
Doing normal right or left hand turns onto different roads has never given me any binding issues. The only time I have ever experienced binding problems is when doing a full lock turn, usually when pulling into a parking spot.

 

Put it in 4wd

It's not complicated, it's not going to hurt anything.

 

It's really about comfort levels but, as others have said, I'd leave it in 2wd in those conditions (with traction control turned off). My snow driving is rarely straight flat roads but I understand steering into a slide, have tires with the M&S snowflake rating and replace them every 4 years (well before I hit the wear bars), and a good amount of weight in the back (2 spares, a HC rear bumper, skids, sliders, a GFC, a fridge & recovery gear).

Unless I cannot keep forward momentum or I'm constantly having to counter-steer, I prefer to keep it in 2wd as I'm more in tuned with the available traction. The pic below is at the top of the mountain after climbing from 4k ft to 8k ft in the snow using just 2wd. It's also worth noting that you'll have a much easier time correcting a slide at 50mph that at 65 or 70mph.