Snafu in Slippery/4 wheel hi mode

[Kurto125]

In the monsoon rain day before yesterday, on my 2023 Big Bend with factory tires and 22k on the odometer, I decided to try the "Slippery" GOAT mode, which shifts the transmission into 4 wheel drive high. As I was making a sharp left into my parking space at home, the whole system bogged down, and I had to give it significant throttle to get it to move.

Normal? (hope not!) Defect? Thoughts?

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[DarthLincoln]

Yes this is normal. In 4-Hi the clutch pack in the center transfer case fully engages, which forces the front and rear driveshafts to spin at the same speed. When you make a turn, the front driveshaft needs to turn faster than the rear driveshaft because the front tires make a larger arc (covers more distance) - this required speed difference increases with sharp turns.

On slippery surfaces, this is not an issue because tires are able to slip. On less slippery surfaces like rain on asphalt, you should still be ok if driving straight or making only gradual turns, like on a wet highway.

But if you make a sharp turn that requires a larger difference between front and rear wheel speed, if the surface isn’t slippery enough, the vehicle bogs down because you need more torque to force tires to slip more. So switch back to 2WD.

 

[BroncoChallenger]

If you have Auto 4x4, I would recommend that on rainy surfaces if you're going to want/need all 4 wheels to have power. Otherwise, I wouldn't use 4wd on asphalt OR concrete - just not enough slip, even when they're wet.

Snow/Ice is a different story.

 

[Sparkherd]

4H (or 4L) is NOT FOR TURNING ON HARD SURFACES, in the rain or not.
I don't think the transfer case chain is ridiculously expensive, but the labor to replace it sure as hell is.
Use 4A if you have it.
This would be a Good Time to familiarize yo bad self with 4WD systems...

 

[Figmo]

Unless it's raining frogs, rain is typically not "slippery" enough to risk using 4H.

And I use the word "risk" deliberately here. because that's basically what you're doing when you decide which mode to be in. You're weighing risk. The risk of getting stuck or losing control vs. the risk of doing damage to your drivetrain from excess stress on the components.

 

[DALOLA]

Another reason to never buy a 4x4 without 4A.....

 

[Danielsand]

Another reason to never buy a 4x4 without 4A.....

Or......attend a driving school perhaps?

 

[Kurto125]

Yes this is normal. In 4-Hi the clutch pack in the center transfer case fully engages, which forces the front and rear driveshafts to spin at the same speed. When you make a turn, the front driveshaft needs to turn faster than the rear driveshaft because the front tires make a larger arc (covers more distance) - this required speed difference increases with sharp turns.

On slippery surfaces, this is not an issue because tires are able to slip. On less slippery surfaces like rain on asphalt, you should still be ok if driving straight or making only gradual turns, like on a wet highway.

But if you make a sharp turn that requires a larger difference between front and rear wheel speed, if the surface isn’t slippery enough, the vehicle bogs down because you need more torque to force tires to slip more. So switch back to 2WD.

Thanks. Got it.

 

[Kurto125]

4H (or 4L) is NOT FOR TURNING ON HARD SURFACES, in the rain or not.
I don't think the transfer case chain is ridiculously expensive, but the labor to replace it sure as hell is.
Use 4A if you have it.
This would be a Good Time to familiarize yo bad self with 4WD systems...

Thanks. I've had Jeep CJs and other 4wds over 50 years. Never experienced this.

 

[Kurto125]

If you have Auto 4x4, I would recommend that on rainy surfaces if you're going to want/need all 4 wheels to have power. Otherwise, I wouldn't use 4wd on asphalt OR concrete - just not enough slip, even when they're wet.

Snow/Ice is a different story.

Thx

 

[bassist]

Another reason to never buy a 4x4 without 4A.....

Why?

You don’t need 4WD if you can see the color of the road.

Hell, get the right tires and you don’t need 4WD unless you are offroad…and even then not necessarily.

 

[DALOLA]

Why?

You don’t need 4WD if you can see the color of the road.

Hell, get the right tires and you don’t need 4WD unless you are offroad…and even then not necessarily.

I don't know what kind of winter road conditions you have in VA, but here it's a mixed bag all winter....road surfaces can be dry, wet, snow, and ice....all within just a few miles. 4A is superior for these kinds of mixed road surfaces. I had one F150 4x4 that did not have 4A, never again. It's not about "need", it's about what works best.

 

[Kurto125]

Why?

You don’t need 4WD if you can see the color of the road.

Hell, get the right tires and you don’t need 4WD unless you are offroad…and even then not necessarily.

As I said, I merely activated "Slippery" GOAT mode, which itself engages 4HI. Interesting to hear Slippery mode is useless.

 

[RedDawg]

In the monsoon rain day before yesterday, on my 2023 Big Bend with factory tires and 22k on the odometer, I decided to try the "Slippery" GOAT mode, which shifts the transmission into 4 wheel drive high. As I was making a sharp left into my parking space at home, the whole system bogged down, and I had to give it significant throttle to get it to move.

Normal? (hope not!) Defect? Thoughts?

Really needs to be slippery, to use Slippery. I.e. back end sliding during turns. I don’t get ice or snow here in PHX. But I use Slippery when driving the hard pack dirt roads that are covered in scrabble. Works great!

 

[dgorsett]

As I said, I merely activated "Slippery" GOAT mode, which itself engages 4HI. Interesting to hear Slippery mode is useless.

It is valuable in snow and ice. In rain it's fine just hit the 2H button after engaging Slippery. It will gentle down the throttle and shifting while enhancing traction control.

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