4WD

[Sigil]

Hello. I am a new jeep owner, and bought a 2020 Wangler unlimited sport. Today I engaged 4WD for the first time as it was raining a lot and I was actually surprised how much the jeep slips in the wet.
When turning hard lock to the left or right the car jolted and felt like it didn’t want to move. Is that normal? Didn’t feel smooth at all when driving in 4WD.

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[GATORB8]

Yes, with full traction, something has to give.

No reason to drop it in 4 for rain on asphalt.

 

[DWaX]

There really isn't any reason to go 4wd on pavement unless its snow/ice. The wear (stretch) on the T-Case chain over time just isn't worth it.

WaX

 

[Bikemobile]

Buy better tires for everyone’s sake.

 

[Tethmes]

4X4 isn't the same as AWD on something like a Subaru. You are risking damage to the drivetrain using it on pavement. Even in the rain. I'd suggest something simpler like using your right foot more conservatively.

 

[aldo98229]

Welcome to the scolding...err...to the forum!

 

[GATORB8]

Welcome to the scolding...err...to the forum!

Lol, yeah, OP, you didn’t hurt anything.

 

[Tethmes]

Lol, yeah, OP, you didn’t hurt anything.

To be fair, I didn't say he DID damage anything. But that it's a risk. Cuz you know he was out there doing 70 or 80 mph with 4x4 engaged.

 

[Sigil]

Thanks for all the comments.
No I wasn’t going 70 or 80, the jeep slips turning out of driveway. Tires are good, but going to upgrade them. Just surprised how much it slips!

 

[somedude922]

Holy cow, PLEASE read you manual! The "slipping" you are feeling is the front drivline binding up when you turn. It can also feel like its hopping. Driving in 4x4 is rarely needed. It is NOT needed on paved roads, especially when wet.

 

[rcadden]

This is a common misconception. 4WD =/= AWD. I would highly recommend that you watch a few YouTube videos on the difference between the two. Tires will help with traction, but will not resolve the jumpy/locked feeling - that's a result of attempting to use 4WD where it's not needed.

AWD is going to be much better for pavement - wet or iced, etc.
4WD is typically better whenever you're not on pavement - either dirt roads, or pavement with heavy snowfall, etc.

Either way, welcome to your new Jeep and this community. While you're likely to get ribbed quite a bit, especially with beginner questions, this is actually a really nice, helpful, positive community. Take your hazing in stride and don't get easily offended and you'll learn a ton.

 

[Mikeoso]

The 4WD in a Wrangler is ihtended for use where the tires are slipping and digging. As stated above, it's not like AWD systems that allow independent traction. If the tires cant spin, they will jump and bind when turning. Dont use 4x4 on pavement unless it's ice or snow covered.

 

[J-Frame]

The thing I’ve noticed here is that folks laugh WITH you and not AT you. Big difference.

But yes, the jumpy, slIpsy feeling you experienced is the 4WD system binding up because it had too much traction in those conditions. You didn’t hurt it, and it is good to actually know what it feels like. And don’t ever use 4WD on dry pavement.

 

[Pinky Tuscadero]

If it was slipping in the rain then you've probably got roads that get oily and slick when it rains - yeah ! - use the 4 wheel high if needed but watch that cornering and get it out as soon as not needed for sure.
I have 3 intersections that do this near me in rain... this didn't used to happen at them but does now and many cars slide in only rain on them, I don't know the cause but it is real.
None of these people were in your Jeep and none of them will be there for your accident so please.... do what you feel is needed for yours and everyone else's safety
And also, its not just under heavy snowfall that 4 wheel drive is needed nearly as much as that very first inch as with the rain when the oils come out early in the rainfall and are gone by the time the monsoon hits - we basically have rear wheel drive vehicles with most weight in the front so... they do that
" the jeep slips in the wet" - yeah, this is why you bought 4 wheel drive so use it for now but, yeah, like they said check your tires too. KO2's and Cooper AT3's I've had are awesome for traction and last very, very long and with a 2020 it may be time anyways - also a good time to size up a couple inches just for fun ?

 

[jeepoch]

@Sigil,

Simon, you'll continue to likely receive the input of something like "just don't do it". Unfortunately without much reasoning as to why. Hopefully this response may help.

When turning, the distance that must be traveled by the outer front wheels due to a wider turning circle than the inner rear wheels causes a difference in the rotational speeds of the front and rear wheels. This, in turn, causes a difference in the speeds of the front and rear driveshafts.

It is this difference in drive shaft rotation rate that causes 'binding' throughout the entire drivetrain. This binding energy can wind up to the point where mechanically "something has to give". Hopefully, what gives is tire slip and not shaved teeth in your differential, transfer-case, transmission, broken u-joints or bending of the drive shafts.

Whenever you turn in 2wd, power is only applied to just one axle, typically the rear. And the differentials (pumpkins) allow this difference in wheel speeds. Recall, the differentials are normally open (unlocked). This allows each wheel to rotate at different rates. Hence no binding.

By adding power to both axles (4wd), all four wheels are now spinning at different rates while turning. Each differential is still doing it's job on its own axle but the speed difference overall between the two axles is now what's causing the drivetrain binding. And because the force vectors are greatest on the wheels with the greatest change in radius (the front) it is generally the front tires with the lowest coefficient of friction and thus 'slip'.

If the ground to tire friction is high enough (dry pavement) then powertrain damage can result.

Partial 4WD and AWD systems are explicitly designed to handle the rotational difference between axles whereas full time 4wd is not.

So moral of the story with full time 4wd systems is to use 4wd mode (either 4hi or 4lo) either off-road or slippery conditions only. Noting here that with modern new tires, wet conditions may not be slippery enough.

Hope this helps with more of the physics behind your experience.

Best regards,
Jay

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