New to 4x4, is it supposed to do this?

[AH64ID]

Speed limit on 4wd??? How does that apply? Everything is spinning the same in 2wd or 4wd, unless you have a spin free kit.

If you have 4 tires are 4 different tires pressures, like we all do (yes 1 psi makes a difference), and 4 different weights then you will get drive-line binding on a high traction surface. Rain covered roads are high enough traction.

I am in and out of 4wd all the time when road conditions warrant.

I would really like a AWD/4WD transfer case in these trucks but that's not an option.

 

[kthaxton]

I determined a long time ago.....if conditions require (or might require) 4wd, I better not be driving over 60-ish....and that's pushing it.

 

[kthaxton]

Speed limit on 4wd??? .

I don't recall reading any limits on my '15, but my 86 (for sure) and maybe my 2000 said not to go over 55 while in 4wd. Maybe its as simple as the intended rotational speed of the front driveline? Limited or lack of balance? Max intended speed of the chain? Not really sure.

 

[AEdelheit]

Speed limit on 4wd??? How does that apply? Everything is spinning the same in 2wd or 4wd, unless you have a spin free kit.

If you have 4 tires are 4 different tires pressures, like we all do (yes 1 psi makes a difference), and 4 different weights then you will get drive-line binding on a high traction surface. Rain covered roads are high enough traction.

I am in and out of 4wd all the time when road conditions warrant.

I would really like a AWD/4WD transfer case in these trucks but that's not an option.

Actually the static radius of a tire should not change on tire pressure unless its severely over inflated. If you have the tires set to the proper psi for the weight then its not an issues.

Agreed, I love driving the wife's AWD Grand Cherokee and not worrying about weather to be in 2wd or 4wd.

 

[AEdelheit]

I determined a long time ago.....if conditions require (or might require) 4wd, I better not be driving over 60-ish....and that's pushing it.

Guessing you haven't driven off road in sand or loose dirt much? Required and nice to have the front axle pulling are 2 different situations as well.

 

[kthaxton]

Guessing you haven't driven off road in sand or loose dirt much? Required and nice to have the front axle pulling are 2 different situations as well.

Well, yes, many times but I'm not a desert racer, I'm not doing that at 70 mpg. I'm talking about on the highway, on slippery surfaces.

If we are referring to Baja racing, I apologize, I was not aware. If we are talking about folks that drive their Diesel equipped Ram's (this is the 4th generation forum) like most people do, then my point is valid.

 

[Tuesdak]

Run 4x4 when you need it. Parts are cheap in perspective.

In Sunny Arizona during the winter you can forget to bring a jacket going into higher elevations. IMO with snow and ice around it's safer to be in 4x4 considering the following situation.

Some poor driver in a small white car likely still has flashbacks about becoming the cream filling after a possible head on with a 18 Wheeler behind them.

Dry roads and just finished pulling a grade with a 24' trailer. Still under heavy power entering a slight curve 2 lane road.

On the uphill side there was a small snowbank with the water crossing the road that had frozen into black ice.

The rear end stepped out under power when it hit the black ice as the truck was in 2x4. It would not have stepped out in 4X4.

The skid marks were impressive from all 8 tires as the steering was put lock to lock several times to get it back in a straight line.

The oncoming head on small car and 18 Wheeler were incentive to get it straightened out...

I will run 4x4 on dry pavement when conditions like this are around from now on.

 

[AH64ID]

Actually the static radius of a tire should not change on tire pressure unless its severely over inflated. If you have the tires set to the proper psi for the weight then its not an issues.

Or underinflated. Then you run into temperature changes based on inflation pressure/load and that effects rolling radius.

Driving a fully locked rear on the street can show one just how much difference there is in tire rpms, even in a generally straight line. While 4wd isn't quite the same as a true locked rear/front end you still have to have 1 rear and 1 front tire moving at the same rpms to not get binding (assuming open/limited slips).

Agreed, I love driving the wife's AWD Grand Cherokee and not worrying about weather to be in 2wd or 4wd.

The wife's 4Runner has 2wd/AWD-Hi/4wd-Hi/AWD-Lo/4wd-Lo. I have always wanted that transfer case in the 1200 ft/lb rating for my Dodge.

I end up in 4wd a lot of times when it's not really needed just to keep the rear tires from chunking while towing on dirt roads.

 

[kthaxton]

I too like AWD. If it's snowing and I have to travel on the highway.....I prefer driving our Subaru Outback. I don't have to decide whether the roads are slippery enough for 4wd..... it's already on. Plus, I find being lower to the ground more confident inspiring if things get out of control.

 

[Newsa]

Run 4x4 when you need it. Parts are cheap .

Agree with this and the one above that your truck.will tell you when its getting enough traction to take it out of 4x4.

 

[AH64ID]

By the time the average driver is being told something by their the truck the driveline binding is excessive when 4wd is used on high traction surfaces.

Parts are not all that cheap when your talking driveline binding. The u-joints aren't generally what fails, the transfer case is.

 

[mrbb]

By the time the average driver is being told something by their the truck the driveline binding is excessive when 4wd is used on high traction surfaces.

YES I can hit my head on low ceilings and things, OR or just learn to duck when I see low things and NOT get hit in the head!!!

but we all do have to learn some how I guess
guess that;s where the saying about learning the hard way comes into play??


and as for a drive shaft spinning when NOT in 4x4 or at what ever speed
there is a BIG difference when there is NO load on one and when there IS a load on one
factory trucks are NOT Baja ready machines
U joints, axle joints and splines , all weak links to a point

I'd rather have one fail on a front end at a slower speed than a higher one!!

I agree use it when you need it
but in ALL my yrs of driving in a snow belt area and on roads in ALL weather
never needed to be in 4x4 at speeds over 45 MPH
if roads are that bad, your asking for an accident
and IF you get in one and they determine you were exceeding speeds PER CONDITIONS< you can get screwed and be held accountable for causing the accident!!
SO< drive as you like in YOUR truck, its your's
but know the possible down sides to, was MY point here
NOT bashing anyone

MANY SO called FULL time 4x4's that I know of, run in 2x4 mode and have sensors that engage front end when it sense's a slip on the back
so its NOT like there driving about in a LOCKED up 4x4 mode vehicle

and MANY of them are SPEED controlled and DON"T engage at speeds over a set limit??
due to NOT wanting things to NOT mesh up at speed and cause a BIGGER issue
so many of them too are NOT true full time 4x4 vehicles?

 

[Dogpatch]

I've just been experiencing all the buckin and jumpin with the snow we've recently had. Great to be in 4x4 for the snow but NASTY when you come off the snow in a slow turn.

Ive learned to shift out of 4x4 when I'm in a turn going slow forward or backing up.
It also helps a great deal to be in neutral when shifting at next to no speed. It stops a lot of noise!

 

[AH64ID]

MANY SO called FULL time 4x4's that I know of, run in 2x4 mode and have sensors that engage front end when it sense's a slip on the back
so its NOT like there driving about in a LOCKED up 4x4 mode vehicle

The only ones I know that do that call it AUTO 4WD not Full Time 4WD. Auto 4WD just engages a part time system automatically.

 

[mrbb]

OK< so, maybe I am being to wide on my meaning
SOME FULL time so called 4x4 systems work as I stated above, some DON"T
older systems I had more experience with did as I stated, and so do many so called SMART AWD systems

IF anyone cares to read about differences , here is a decent link

http://www.awdwiki.com/en/all+wheel+drive+explained/

 

[Bob4x4]

There are many hi tech transfer cases and low tech,some computer controlled some not,none mass produced that I have run across that will hold up to the weight and torque supplied by our trucks(that will fit)Fca also has some that do not use transfer cases at all but still have all wheel drive some even have low range.As far as the speed limits posted in owners manuals it is all about liability not machinery.My trucks have been north of 100 for many miles and did so with out issues.My old 94 with somewhere around the 1/4 million mark still had the oem case and had never been apart.

 

[sag2]

I can't find the photos now but I looked at a 3500 ambulance last year that broke the transfer case in half after they ran it on pavement down the highway. It did $20,000 in damage before it was all over.
They tried to sue FCA but lost when they interviewed the driver and he admitted it was in 4x4 when it came apart.

 

[Missouri Mule]

As I recall in my owner's manual for my Mule it sates don't shift in 4 wheel high above 55 mph. 4 wheel low needs to be standing still.

I've used 4 wheel high several times with the original Good Year wrangler RT's during hard rains when on the highway (doing 55 mph). When I switched to Wrangler at's and then to LTX M/S tires I haven't needed to put it in 4 wheel high when raining hard. (Now a days Mule is only in 4 wheel high and low when cleaning the weeds out of the ditch along side the road so the water will drain off my parking lot.)

 

[Newsa]

Likewise. I have not had to use 4x4 on wet roads since moving from HT's to AT tires.

The transforce AT's have triple the wet traction that the transforce HT's had. I don't think those HT's should have been M + S rated. Because that's a lie.

 

[Dogpatch]

Personally, the Transforce AT M+S tires suck in the snow and are terrible on ice!

Im going in today to put a set of true winter tires on my new truck. There's another $1K out of the wallet!
Only thing good about that, aside from the added traction I'll get is our fleet tire shop gave me $400 off the set.