Selec Trac full time 4WD once standard on Sport Models

[Casique]

I got it on my 2021 HA, it was an option.

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[LouisvEarlleJT]

They’re not the same thing.
When you engage 4Hi - All 4 wheels are driving.
When you engage 4Auto - it’s driving in 2WD only until it senses slippage. When it senses slippage, it sends power to the front wheels.

I know they’re not the same? Just saying I didn’t see it as this amazing thing. Some folks like it, some folks don’t.

 

[saintpauljeff]

its the single option I traded my 2020 max tow for a 2021 rubicon; like others have stated, in the northern states during the winter, the road terrain is uneven from snow/ice/sleet and I'd rather not have to manually shift 4x4 on/off during a routine drive someplace

 

[Janster]

Do those have a Front Axle Disconnect like the rest? If it does I would guess that it stays engaged so there’s less delay in activation

I’m still trying to learn how it all works….. in terms of the front axle shafts and front driveshaft. I’m used to IFS rigs…which always had them (Front disconnects).
I’m not used to seeing solid front axles with CV joints…or any of that…

I‘m pretty sure my 2024 Mojave X has a FAD……
I honestly didn’t crawl under there long enough to see any wiring to it (behind all the other stuff under there).

So yes… As soon as you put it into 4Auto - Everything (front axle shafts & front drivesahft) should be spinning. Same as it would in 4Hi and 4Lo. The T-case gearing (and clutch paks) would send power to the front driveshaft accordingly.

 

[LouisvEarlleJT]

I’m still trying to learn how it all works….. in terms of the front axle shafts and front driveshaft. I’m used to IFS rigs…which always had them (Front disconnects).
I’m not used to seeing solid front axles with CV joints…or any of that…

I‘m pretty sure my 2024 Mojave X has a FAD……
I honestly didn’t crawl under there long enough to see any wiring to it (behind all the other stuff under there).

So yes… As soon as you put it into 4Auto - Everything (front axle shafts & front drivesahft) should be spinning. Same as it would in 4Hi and 4Lo. The T-case gearing (and clutch paks) would send power to the front driveshaft accordingly.

The need for FAD still exists even with the auto 4WD because the overall situation is still the same. At least that would seem to be the case.

 

[Janster]

The need for FAD still exists even with the auto 4WD because the overall situation is still the same. At least that would seem to be the case.

I would think the FAD prevents the axle shafts (or at least one side) from spinning with the wheels in 2WD - and/or preventing that rotation from transferring into the front driveshaft also. I just never know how the OPEN diff plays a part in all that.

 

[LouisvEarlleJT]

I would think the FAD prevents the axle shafts (or at least one side) from spinning with the wheels in 2WD - and/or preventing that rotation from transferring into the front driveshaft also. I just never know how the OPEN diff plays a part in all that.

So both sides of the front axle spin at all times, (your hubs are directly connected, in both CV trucks and U-joint trucks) the FAD prevents the axles from engaging with the driveshaft - I.e. when in 2Hi the front driveshaft does not spin. Supposedly this gives some amount of fuel efficiency.

When engaged the open front diff works like any other.

 

[NortonJTSS]

I have a 21 Sport S and select track did not not come with it. It was a $695 option that I couldn't get because I ordered a manual (though would have)

 

[jac04]

... and only engage 4WD when it detected front wheel slippage...

They’re not the same thing.
...
When you engage 4Auto - it’s driving in 2WD only until it senses slippage. When it senses slippage, it sends power to the front wheels.

4Auto is driving both the front & rear all the time.

If you search, you'll find info on clutch torque transmission % in different scenarios. The SelecTrac system will be sending significant torque to the front from a stop or at lower speeds. Once traveling faster, the system backs off on torque being sent to the front, but never completely, keeping the system ready to send more power to the front if slippage is detected.

 

[jac04]

I would think the FAD prevents the axle shafts (or at least one side) from spinning with the wheels in 2WD - and/or preventing that rotation from transferring into the front driveshaft also. I just never know how the OPEN diff plays a part in all that.

Here is how the FAD system works. In 2wd, going forward:
LH axle shaft turns forward.
Front driveshaft is stationary.
RH outer axle shaft turns forward.
RH inner axle shaft turns backward.
The differential spider gears are turning, and that is why RH inner shaft turns backward.

 

[jac04]

...
I‘m pretty sure my 2024 Mojave X has a FAD……
I honestly didn’t crawl under there long enough to see any wiring to it (behind all the other stuff under there).
...

The Mojave X does not have FAD. If you did, the Cover Plate held on my the 4 silver screws shown in your picture would not be there and an Actuator would be in its place. like so:

 

[Hootbro]

4Auto is driving both the front & rear all the time.

If you search, you'll find info on clutch torque transmission % in different scenarios. The SelecTrac system will be sending significant torque to the front from a stop or at lower speeds. Once traveling faster, the system backs off on torque being sent to the front, but never completely, keeping the system ready to send more power to the front if slippage is detected.

Thanks for the clarification. I just new it worked and could be driven in 4AUTO for the most part without issue.

 

[Stan H]

4Auto is driving both the front & rear all the time.

If you search, you'll find info on clutch torque transmission % in different scenarios. The SelecTrac system will be sending significant torque to the front from a stop or at lower speeds. Once traveling faster, the system backs off on torque being sent to the front, but never completely, keeping the system ready to send more power to the front if slippage is detected.

Which of course is all due to the Transfer case. And the limited slip rear-ends

 

[Stan H]

Thanks for the clarification. I just new it worked and could be driven in 4AUTO for the most part without issue.

Yes and no locker in front unless and aftermarket has been installed. This is why I believe the Mojave to be inferior on rocks and certian terrain which forces a wheel free in the front. But it does have its strong suites and the 2.72.1 transfer case gives more speed for dunes and sand which is what it was designed for.
Mojave has stronger frame for bounding in a forward and aft position ,Rubicon more flex for rock climbing.
Its all really just about what kicks ya in the pants. I think the reason a rear locker is all it has is because a front e locker wouldnt help it in sand.

 

[Mike Kilo]

When I got my Overland (ordered 5/19, delivered 7/19) Selec-trac wasn't even offered.

I don't think they put into Gladiators until the 2021 model year as an option.

The standard 2H, 4H, N, 4Lo transfer case was all you could get until then, and the standard across all available models.

I wish it was an option when I ordered mine. I had Selec-Trac in two of my Grand Cherokees, my '96 and my '03. LOVED it. Wish I had it in mine but, now that I'm retired, I really don't have to venture out when the weather is inclement or when it's snowy so, there's that.

I'm a Jeep Newbie - drove an AWD (Quadra Track I) Commander for years and loved it but just acquired a pre-owned 2023 Overland - but my understanding as of some convos and research I've done this week is that Jeep's highly regarded BLD - brake lock differential - traction control system is probably superior to Selec-Trac, though it has a slight learning curve.

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