[rynomx785]

So what about guys like me driving up to tahoe for 30 miles of chain control in the mountains. It goes from bad snow to decent tracked out "lanes" of asphault. Should I just click back and forth as the snow/road conditions dictate?

I lived in Tahoe two winters ago. I never even used chains. Even when they said they were necessary. Just click back and forth as you feel necessary. If the roads gets bad at all up there they completely close them down anyway. I had one freaky drive from South Tahoe to Reno early one morning after a decent storm because I was in a hurry trying to catch a flight. I clicked it into 4 hi and still drove 60+ all the way off the mountain. lol

 

[cen28468]

Alright, so I guess I'm an idiot because I never realized all of this. I live in Wyoming, about 20 minutes from work, and a lot of days the roads are covered in snow/ice. I only go about 45 or so when it's bad, but I usually always have it in 4H. I never use 4L, unless I'm stuck or something.

Our parking lot is snowed/iced over today (like about every other day around here), so when I left for lunch, I started up the Titan and clicked it into 4H just knowing I would slip getting out of the parking lot..

When I was backing out it made all kinds of creaking and popping, and then when i started to pull forward it did the same thing, and felt like it was really lagging to go forward. I didn't push it very hard or anything, but now I'm worried I F'd something up. It drove fine after that and everything.

You think it just did it because I was backing out of my spot and had to turn it fairly hard? This is the part where you guys make me feel better about being dumb.:bangit:

 

[g2145]

my previous 4wd vehicle was a chevy trailblazer and it had auto 4wd and it was nice...i miss that feature. it really helped at the inclines with stop signs and lights on the rainy days. 4wd would kick in so fast.
now, i just engage when stopped and disenage when i'm through the intersection, mainly on the inclines.

 

[DeadRiver]

sounds like some binding up front from backing up and turning. if you re-engaged and everything seemed fine, it probably is.

I blew my front differential last year in some deep snow, you'll know when it's toast in that amount of snow.

 

[Anavrin351]

Snow allows wheel slippage when the drivetrain loads up, dry pavement does not. Fast or slow doesn't matter, it's the friction between the tires and road that's the enemy.

so the tires are trying to slip in 4hi, correct? whether on snow/ice which allows the slip, or on dry pavement which doesnt allow slipping.

Im new to part time 4wd. i have a subie and never thought about anything like this before since i have only had AWD.

i read, but didnt understand why turning effects it. the issue is front and rear, not turning right? What if your in snow sliding around( open parking light or something like that) with the wheels fully turned. is that ok since there is slipping going on.

 

[NorCal 4x4]

so the tires are trying to slip in 4hi, correct? whether on snow/ice which allows the slip, or on dry pavement which doesnt allow slipping.

Im new to part time 4wd. i have a subie and never thought about anything like this before since i have only had AWD.

i read, but didnt understand why turning effects it. the issue is front and rear, not turning right? What if your in snow sliding around( open parking light or something like that) with the wheels fully turned. is that ok since there is slipping going on.

Turning on dry pavement or rock is bad when you have the L/R wheels locked together, like you can with a Off Road, or Pro-4x Titans' E-Lock. This completely locks the wheels together, and since the wheel on the inside of a curve has a shorter distance to travel than the outside wheel it's not good unless the tires can slip easily. So if there's no slipping on the inside tire, the outside hops to keep up, and there's a lot of stress on the differential. Some vehicles also have locking front differentials so it would be even worse for them.

 

[rynomx785]

Which is why I don't use my E locker in my truck. I don't trust the added pressure on our junk spyder gears.

 

[NorCal 4x4]

I've used mine crawling up loose rock/dirt jeep hills with no problem. I haven't done much turning with it locked though, because I unlock it at the top, since it's not needed there.

The trails I climb up, allow about 5 or 6 mph max, (so the Titan doesn't slide off the side or into a 3 foot rut), and the E-Lock limit is 12 mph, so this might have something to do with mine being flawless for 118K miles.

Works great for its design goal.

 

[AZPRO4X]

I have used mine several times you just need to be smart about it.

 

[rynomx785]

I've never had my truck in a spot where I need to be locked up to make it. I try to avoid spots like that in the Titan. That's what the Jeeps for. LOL

 

[Yahooligan]

so the tires are trying to slip in 4hi, correct? whether on snow/ice which allows the slip, or on dry pavement which doesnt allow slipping.

Im new to part time 4wd. i have a subie and never thought about anything like this before since i have only had AWD.

i read, but didnt understand why turning effects it. the issue is front and rear, not turning right? What if your in snow sliding around( open parking light or something like that) with the wheels fully turned. is that ok since there is slipping going on.

The issue is turning, or even tires that aren't worn evenly front vs rear, because the front and rear driveshafts are locked together. When you turn, all 4 tires take different paths, which means all 4 tires want to turn at a different speed. With part-time 4wd (t-case locked), there's no center differential to deal with the speed differential between the front and rear driveshafts, so the energy builds up and is either released by tires scrubbing/hopping/slipping or by breaking part of the drivetrain, like a u-joint, CV joint, or even the t-case itself.

AWD and full-time 4WD have 3 differentials; Front axle, rear axle, center/t-case. This is why AWD vehicles can operate on all terrain and pavement, dry or wet.

Part-time 4WD only has differentials in the front and rear axles.

:cheers:

 

[TitanZ04]

Outstanding response to the question(s)....thanks...

 

[Anavrin351]

The issue is turning, or even tires that aren't worn evenly front vs rear, because the front and rear driveshafts are locked together. When you turn, all 4 tires take different paths, which means all 4 tires want to turn at a different speed. With part-time 4wd (t-case locked), there's no center differential to deal with the speed differential between the front and rear driveshafts, so the energy builds up and is either released by tires scrubbing/hopping/slipping or by breaking part of the drivetrain, like a u-joint, CV joint, or even the t-case itself.

AWD and full-time 4WD have 3 differentials; Front axle, rear axle, center/t-case. This is why AWD vehicles can operate on all terrain and pavement, dry or wet.

Part-time 4WD only has differentials in the front and rear axles.

:cheers:

so on our Ts turning with 4hi isnt an issue because we have front and rear differentials. I ask because when im in downtown areas around here we have very steep hills. I put the truck in 4hi to get going without spinning the tire. Sometimes i turn while still going up the hill in 4hi. is that something i should try to avoid.

Sorry, these are probably dumb questions but i am new to part time 4wd.

It

 

[Yahooligan]

so on our Ts turning with 4hi isnt an issue because we have front and rear differentials. I ask because when im in downtown areas around here we have very steep hills. I put the truck in 4hi to get going without spinning the tire. Sometimes i turn while still going up the hill in 4hi. is that something i should try to avoid.

Sorry, these are probably dumb questions but i am new to part time 4wd.

It

Yes, avoid it unless the roads are sufficiently slick to let the tires slip, such as with snow or ice. Rain is not slick enough. Both 4HI and 4LO are part-time which means the front and rear driveshafts are locked together. There is no full-time or AWD mode.

The 4WD in the Titan is something that should only be used in mud, dirt, snow or ice. Never if the road is just wet with rain, especially if you're making turns.

 

[CVTitan05]

I always thought that all 4 tires are spinning at the same rate in 4wd so it doesn't make a difference if you are on pavement or sand?

Why would the tires spin at DIFFERENT rates? If the gearing is all the same, then the amount of the driveshaft to the rear diff is spinning equally with the driveshaft to the front diff? So everything is spinning at the same rate, yet ALL 4 tires are spinning at different rates?

This is where im confused.

 

[NorCal 4x4]

I always thought that all 4 tires are spinning at the same rate in 4wd so it doesn't make a difference if you are on pavement or sand?

Why would the tires spin at DIFFERENT rates? If the gearing is all the same, then the amount of the driveshaft to the rear diff is spinning equally with the driveshaft to the front diff? So everything is spinning at the same rate, yet ALL 4 tires are spinning at different rates?

This is where im confused.

It's because of the open differentials needed for curves, (the inside wheel travels a shorter distance).

When a true locker, (like the rear e-lock on the off road and Pro-4x), is engaged, the outside wheel will get dragged by the inside wheel taking a shorter path.

But even when not locked, the front and rear get locked together in 4wd, and so different paths in the turn can cause stress on the various parts of the drivetrain in addition to the tires. In loose off road conditions the tires' slippage will tend to protect the truck and themselves to some degree.

Even going straight, the small differences between the locked front and rear in 4wd, (even from different tire pressure, alignment, etc.) can cause additional stress to the components and excessive tire wear when used on dry pavement. All wheel drive vehicles, like a Subaru, use a form of differential between the front and rear as well as on each axle, so are meant to be used on dry pavement as well as in slick conditions.

 

[Jiro]

I've used my 4Hi to get into some steep, uneven paved driveways on the jobsite. Needed it to reverse up hills that my dads 2500 Ram could just reverse into. Shows what an LSD rear will do. Haven't had to do that since I did the diff lock mod though. Oh yeah, I've done dry pavement turns and could feel the truck binding, having to give it more throttle than I should. Knew it wasn't good but didn't really have a choice. 47k miles and no problems so far...

 

[Windza]

Interesting thread guys (and quite old too I see) but personally I'd be VERY surprised if the damage seen in the OP's link was caused purely by bind-up...

I'm not denying it's bad practice to use 4WD on dry pavement for extended periods of time and that drivetrain stresses are dramatically increased by doing so BUT traction plays a huge part in how much bind-up can be generated...

We all know turning sharply in locked 4WD causes one or two wheels to slip/chatter/spin which subsequently releases an element of the stresses...
I'm inclined to think that at highway speeds, this stress would be dissipated easier through wheel slip than during low speed sharp turn manoeuvres where traction on dry pavement would be significantly higher.

I've never seen a transfer case split in two because of bind-up and I'd suggest this has occurred due to some other inherent issue like fatigue, heat or impact for which bind-up was merely a contributing factor to the actual failure.

Happy to be proven wrong though

 

[NorCal 4x4]

Happy to be proven wrong though

Just leave it in 4-Hi for a couple of months, and include a lot of long 70 mph, (112.7 kph), pavement runs, then report back. :eyebrow:

 

[Windza]

Just leave it in 4-Hi for a couple of months, and include a lot of long 70 mph, (112.7 kph), pavement runs, then report back. :eyebrow:

Well the context was "after driving 150mi" the transfer case "exploded"... not a couple of months... but I readily acknowledge it's not a good choice.