Going in 4WD over 45 mph

[DirtyCreeker]

You know, there is a way to find out just how fast someone can shift into and drive in 4wd. Who wants to volunteer?

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[wibornz]

This post sounds like a whole lot of no thank you to me. As much as I hate the CA politics, between the winters, the humid summers, and mayflies, I wonder why anyone lives anywhere from New England to Wyoming. We tried northern Pennsylvania for a year and the summers were worse than the winters for me. I'll stay in the south west where I can drive up to the snow in an hour or 2 and never have to deal with it otherwise.

This is my last winter in Michigan. My wife retires in October and then we will leave January 1st to wheel from Arizona to Alaska and chase the seasons doing it.

 

[wibornz]

You know, there is a way to find out just how fast someone can shift into and drive in 4wd. Who wants to volunteer?

I have done it at 60 mph.

 

[Zandcwhite]

This is my last winter in Michigan. My wife retires in October and then we will leave January 1st to wheel from Arizona to Alaska and chase the seasons doing it.

We are still 15 years from retirement, but we are looking at property in Northern Arizona. Great weather, great prices, very libertarian politically, low taxes, etc. It checks all the boxes for retirement location for us. An eventual Alaska trip has been discussed, but taking 2+ straight weeks off is tough for the wife to work into her schedule and very expensive for me as an electrician.

 

[limeade]

You know, there is a way to find out just how fast someone can shift into and drive in 4wd. Who wants to volunteer?

I've done it at 70 mph. I tried at 73ish and wouldn't go. I kept slight pressure on the shifter and as soon as the speedo hit 70, it went into 4Hi as smooth as if it were at 45 mph.

 

[Nomad]

I’ve been right there under similar conditions, just once. Beautiful. Of course I grew up in New England and even plowed snow there so I don’t fear the winter weather. You make decisions and choices and cope. And I echo your rant about people driving too slow. Only comfortable with 45mph? If that’s okay, then what about if you’re only comfortable with 30mph? 20mph? Yes you can go too slow in any conditions. You are right, if you are that scared that 95% of everybody else on the road is going faster than you, stay home. Everybody has to consider everybody else, even slow drivers.

 

[Paulguy100]

On the JK Rubicon, the max speed 2H - 4H was 55 mph. On the JL Rubicon it is 45 mph due to the addition of the FAD. Slow down to 45 mph when shifting the T-case and be kind to your Jeep.

What is FAD?

 

[Mike921921]

Now I’m confused......

the SHIFTING speed (max speed to shift into 4H) is 45 mph. I do not see a maximum driving speed in the manual while in 4H. I do see a max speed for 2L.

leaving all safety issues of driving 70mph on a freeway in a snowstorm, I want to ask this question with a hypothetical circumstance:

a MASSIVE newly paved and totally flat parking lot like one that surrounds a football stadium but 10x as large. It is covered in 3” of fresh snow and it has ice patches under the snow everywhere. You are granted Access to the parking lot ALONE for 1 hour.

are you folks suggesting that the Jeep cannot be put into 4H and then driven around that parking lot at 65mph without doing damage to the jeep?

Believe me, if there was a maximum speed, (due to product liability concerns) FCA would have spelled it out VERY, VERY CLEARLY in the manual.

 

[Heimkehr]

What is FAD?

Front Axle Disconnect. It refers to the function whereby 4WD is engaged and disengaged.

 

[calemasters]

What is FAD?

FAD = Front Axle Disconnect. It prevents the front drive shaft from rotating when you are in 2WD by using a stepper motor to mechanically disconnect the outer section of the front right axle from the inner section of the axle.

 

[LoganDzwon]

I’ve run 80+ on dirt many times. I don’t shift into 4wd at speed though. That’s crazy talk.

 

[smokeythecat]

I cannot tell you how many miles I've driven on dirt/mud/gravel/sandy roads in 4wd (not AWD) at speed well above 45 mph, in all of my trucks and my Jeep in 4wd Hi.

Mechanically, there is no issue as long as the surface allows tire slippage, which is why you would want 4wd anyway.

Safety is a different issue. Many Jeepers do rock crawling and other activities in there Jeeps that has higher risk than driving over 45 mph on a low traction road. You want "safe", stay home and drive a Jeep video game.

What about driving 65 for about an hour on a freeway that is largely just straight ahead driving? I forgot to switch back to 2H when coming off the trail a few weeks ago and didn't notice until I was almost home. I haven't noticed anything that might indicate damage, but I'm not knowledgable enough to know if I could have done some hidden damage.

 

[hoch]

What about driving 65 for about an hour on a freeway that is largely just straight ahead driving? I forgot to switch back to 2H when coming off the trail a few weeks ago and didn't notice until I was almost home. I haven't noticed anything that might indicate damage, but I'm not knowledgable enough to know if I could have done some hidden damage.

You should be fine. It’s the sharp turns that bind up the drivetrain that may cause issues.

I usually wheel in places like Moab and surrounding areas with lots of slick rock. Which is grippier than asphalt. We’re turning, tires squealing, and I’m sure some binding going on. No issues.

 

[Zandcwhite]

What about driving 65 for about an hour on a freeway that is largely just straight ahead driving? I forgot to switch back to 2H when coming off the trail a few weeks ago and didn't notice until I was almost home. I haven't noticed anything that might indicate damage, but I'm not knowledgable enough to know if I could have done some hidden damage.

It will be fine. The only potential damage comes from binding making tight turns on grippy surfaces, which is still unlikely. Odds are your tires will break traction before you break anything even doing that.

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