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Front axle lock vs dry pavement/snow/mud/sand


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Hi Bullnose’s friends!

Please don’t answer “look at you sun visor sticker” or “read your owner’s manual”. :nabble_smiley_wink:

I did so often that I think I could tell by heart. But there’s still something not clear for me…

Q1: Dry road tolerance:

Snowy roads aren’t all the way. You can ride snow, now for couple of minutes have a dry pavement, then snow again… Can I break something if I don’t jump in-out the truck each time the condition changes in order to lock/unlock the front hubs? What is the «dry pavement condition tolerance» for a locked axle?

Q2: Locked hubs + 2WD shifter position

This heads us to my second question: In such changing road conditions, is this a good idea to simply disengage the 4x4 and leave the axle locked? What’s the impact on the transfer case/tranny?

If this is a way to do, what is the tolerance, how munch time can I ride this way on a dry pavement?

Following your advices, maybe it could modify my “jump-in-jump-out” winter driver’s strange behavior.

:nabble_smiley_happy:

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A1: As long as you don't turn any corners you should be able to go quite a ways on dry pavement with the hubs locked and it in 4WD. But that's not the real world. Instead, if you have short patches of dry pavement with a gentle curve or two then the binding created in the turns will be released when you hit snow again.

A2: You can truly drive forever, regardless of the pavement conditions, if you have the hubs locked but put the transfer case in 2HI. It isn't recommended as you have a whole lot of spinning parts, but there's nothing that it will hurt - except your gas mileage.

So I'd simply leave the hubs engaged and shift to 2HI when you come to those dry patches - if they are long enough and/or have corners in them. It is the corners that have the front tires tracking differently from the rear tires and, therefore, going a different distance. And the different difference means differing amounts of rotation on one end vs the other, which is the problem - the transfer case doesn't like that.

But if you don't have it in 4WD then the difference front/rear doesn't matter.

Also, note that I've disregarded the slight difference in gear ratios front/rear that Ford built in on most trucks.

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I'd just leave the hubs locked on snow - patchy or otherwise - and run in 2WD. If you run into trouble, there's no problem stopping and shifting into 4-hi. I've heard before that it's sometimes good to just lock in the hubs and drive a little bit in 2WD anyway; the point was that it helps with front end lube? Sounds hokey, but just scuttlebutt I've heard in the past.
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I'd just leave the hubs locked on snow - patchy or otherwise - and run in 2WD. If you run into trouble, there's no problem stopping and shifting into 4-hi. I've heard before that it's sometimes good to just lock in the hubs and drive a little bit in 2WD anyway; the point was that it helps with front end lube? Sounds hokey, but just scuttlebutt I've heard in the past.

Actually, I think I found that in the owner's manual for a later truck. I was having a leak from the right seal on the front D60 on Big Blue and someone pointed out that I was supposed to lock the hubs every once in a while to move the lubricant around. Sure enough, that fixed it.

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Same here, I leave the hubs locked and shift in and out of 4WD per the road conditions.

in bad weather, snow or ice related, I just lock the hubs and use 4wd as needed. I did this with my excursion years ago while visiting in new England for a week. I locked the hubs on my way in at the first sign of packed snow and left it that way for probably 700 miles. it will add a little rolling resistance but nothing it's not meant to handle. the whole issue is when conditions cause the front/ rear driveshafts to be loaded differently and trying turn out of sync putting the transfer case in a bind. awd has forgiveness designed in yet 4wd does not. something has to slip a little to allow differential.

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in bad weather, snow or ice related, I just lock the hubs and use 4wd as needed. I did this with my excursion years ago while visiting in new England for a week. I locked the hubs on my way in at the first sign of packed snow and left it that way for probably 700 miles. it will add a little rolling resistance but nothing it's not meant to handle. the whole issue is when conditions cause the front/ rear driveshafts to be loaded differently and trying turn out of sync putting the transfer case in a bind. awd has forgiveness designed in yet 4wd does not. something has to slip a little to allow differential.

As others have said, no trouble with locking the hubs and leaving it in 2WD except when you need 4WD. In fact, that's what a lot of newer 4WDs do anyway. My '07 Dodge doesn't have locking hubs. Neither do Jeeps. I lock my hubs if I think I might need 4WD and I unlock them when I know I won't. They might be locked for days (and if I lived in an area that got more snow, maybe for months).

Once your hubs are locked you can shift in and out of 4WD at any speed. It's best not to shift into 4WD when you are turning, but a slight curve typically isn't any issue. But when you are going straight everything is turning the same speed, so there's no need to stop to shift into 4WD. You don't want to be spinning or sliding your tires when you shift, so push in the clutch (with a manual) or shift into neutral, or at least back off the throttle with an auto. But the point is to make sure the front and rear driveshaft are turning the same speed. As long as they are you can shift in or out of 4WD.

OK, now the controversial part. When can you use 4WD? My answer to that is a lot more than what you might think from reading the visor. If the main roads are slippery I'm in 4WD. There are definitely some bare pavement spots where some people would say I ought to be in 2WD. But I don't think it's that big a deal. First of all, an empty pickup doesn't get that good traction in the rear anyway, so a little tire scrub won't be a big deal (if I'm heavily loaded I might use 2WD more in those situations). And truck axles, U-joints and driveshafts are pretty tough. A full throttle start is going to put more torque on the drive line than driving around a curve. Now if you are getting some crow-hopping, that's a different story. The load-unload shock isn't good for things. But I've never experienced that in typical driving. And if I'm turning sharp on bare pavement I will shift into 2WD.

Another controversial point - should you use 4WD on the freeway? Some people say no way, it lulls you into a false sense of security and lets you overdrive your brakes and steering. They say keep it in 2WD and only use 4WD if you get stuck. Sorry, but I think that's foolish. Do you know why it can lull you into a false sense of security? Because it's so much more stable in 4WD! Why would you choose to drive a truck that's trying to go in the ditch when you can drive a truck that wants to go where you point it? True, your brakes aren't much better in 4WD (although for trucks without anti-lock brakes they are still a little better because it's easier to not lock one or two tires). But you can steer better, and you can go straight WAY better. And being in 4WD doesn't mean you HAVE to overdrive your brakes. That's a choice you make. So use some common sense and don't.

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Another controversial point - should you use 4WD on the freeway? Some people say no way, it lulls you into a false sense of security and lets you overdrive your brakes and steering. They say keep it in 2WD and only use 4WD if you get stuck. Sorry, but I think that's foolish. Do you know why it can lull you into a false sense of security? Because it's so much more stable in 4WD! Why would you choose to drive a truck that's trying to go in the ditch when you can drive a truck that wants to go where you point it? True, your brakes aren't much better in 4WD (although for trucks without anti-lock brakes they are still a little better because it's easier to not lock one or two tires). But you can steer better, and you can go straight WAY better. And being in 4WD doesn't mean you HAVE to overdrive your brakes. That's a choice you make. So use some common sense and don't.

I fully agree with that, and not just on ice or snow but also in rain. I've not done it in Big Blue, but I have in Blue, which has AWD in addition to 4WD. And the difference when you hit serious ponding is amazing. Instead of being slowed and the truck wanting to go one way or the other it'll pull right through.

It depends a lot on the road and the amount of rain. I don't do it on good roads that drain well or light rain. But when we are in a deluge or on roads that pond badly, meaning the lanes have ruts that hold water, I do it. And I can really tell the difference - or could until the "integrated wheel ends", aka automatic hubs, failed again. :nabble_smiley_cry:

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Another controversial point - should you use 4WD on the freeway? Some people say no way, it lulls you into a false sense of security and lets you overdrive your brakes and steering. They say keep it in 2WD and only use 4WD if you get stuck. Sorry, but I think that's foolish. Do you know why it can lull you into a false sense of security? Because it's so much more stable in 4WD! Why would you choose to drive a truck that's trying to go in the ditch when you can drive a truck that wants to go where you point it? True, your brakes aren't much better in 4WD (although for trucks without anti-lock brakes they are still a little better because it's easier to not lock one or two tires). But you can steer better, and you can go straight WAY better. And being in 4WD doesn't mean you HAVE to overdrive your brakes. That's a choice you make. So use some common sense and don't.

I fully agree with that, and not just on ice or snow but also in rain. I've not done it in Big Blue, but I have in Blue, which has AWD in addition to 4WD. And the difference when you hit serious ponding is amazing. Instead of being slowed and the truck wanting to go one way or the other it'll pull right through.

It depends a lot on the road and the amount of rain. I don't do it on good roads that drain well or light rain. But when we are in a deluge or on roads that pond badly, meaning the lanes have ruts that hold water, I do it. And I can really tell the difference - or could until the "integrated wheel ends", aka automatic hubs, failed again. :nabble_smiley_cry:

Bought new 86 K5 diesel Blazer sold with 235K

At first snow I locked the hubs in and stayed that way all winter till spring and then un-locked.

I would drive in 2wd as much as I could but when needed shift to 4 hi and could do it at speed as long as the rear wheels were not spinning, read going faster than the fronts.

Once I did not need 4wd back to 2wd till spring.

No need to jump out to lock / un-lock hubs because of patches of snow :nabble_anim_crazy:

With the 02 Durango no hubs to lock, just turn the knob on the dash.

Up north once in a while I would flip it to 4 lo and drive across the long dry parking lot, back to 2wd to turn around and back to 4 lo back to the other end just to get lube moving.

To tell the truth I have not done this in almost 8 years as there is no need to 4x4 here in NC where I am at.

They get anything and they shut down the state :nabble_anim_crazy:

Dave ----

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