Any 2024 model year transfer case failures ?

[ParadigmDawg]

A guy logged the transfer case clutch torque applied with a JScan OBD2. The clutch slips easily in 4A , locks up much more ( but not 100%) in 4P. It locks 100% in 4L.

So , you burn a lot of clutch in 4A , much less burn in 4P and no burn in 4L. Pick your poison.

I always just slap mine in 4L when I hit the trails. Not like I am in a hurry at that point.

 

[Viking Jeeper]

A guy logged the transfer case clutch torque applied with a JScan OBD2. The clutch slips easily in 4A , locks up much more ( but not 100%) in 4P. It locks 100% in 4L.

So , you burn a lot of clutch in 4A , much less burn in 4P and no burn in 4L. Pick your poison.

Good information. I dont really know but if its the clutch slipping wouldn't that just wear it out rather than grenade it?

 

[Viking Jeeper]

I always just slap mine in 4L when I hit the trails. Not like I am in a hurry at that point.

I avoid 4lo out of habit. It's a pain in my manual LJR until I REALLY need it.

 

[guruman]

A guy logged the transfer case clutch torque applied with a JScan OBD2. The clutch slips easily in 4A , locks up much more ( but not 100%) in 4P. It locks 100% in 4L.

So , you burn a lot of clutch in 4A , much less burn in 4P and no burn in 4L. Pick your poison.

"Torque applied" and slip are not 100% correlated.

Slip can only occur if there is an overall wheel speed difference between the front and rear axles. (spinning tires or sharp turns)

Anytime you are driving in a straight line with no wheel spin, there is zero potential for the clutch to slip, regardless of the torque applied reading from Jscan.


Likewise, any time you have a difference in overall wheel speed between the front and rear axle, it has the potential to overcome the static friction force of the clutch, even if the torque applied is at 100%

I dare say in most instances, the torque applied setting has almost nothing to do with whether or not the clutch is slipping.

 

[onfire392]

"Torque applied" and slip are not 100% correlated.

Slip can only occur if there is an overall wheel speed difference between the front and rear axles. (spinning tires or sharp turns)

Anytime you are driving in a straight line with no wheel spin, there is zero potential for the clutch to slip, regardless of the torque applied reading from Jscan.


Likewise, any time you have a difference in overall wheel speed between the front and rear axle, it has the potential to overcome the static friction force of the clutch, even if the torque applied is at 100%

I dare say in most instances, the torque applied setting has almost nothing to do with whether or not the clutch is slipping.

The default logic places the clutch open and rwd for fuel mileage. Apply throttle and it applies the clutch to engage the front axle. That has to wear the clutch and it also impacts the transfer case gear. That creates a potential wear item in both. 4A plus 392 plus a lot of throttle plus a lot of Offroad in 4A………

 

[guruman]

The default logic places the clutch open and rwd for fuel mileage. Apply throttle and it applies the clutch to engage the front axle. That has to wear the clutch and it also impacts the transfer case gear. That creates a potential wear item in both. 4A plus 392 plus a lot of throttle plus a lot of Offroad in 4A………

Um... no, no it doesn't. Engaging and disengaging the clutch when the front and rear driveshafts are running the same speed does not wear the clutch face. the engage/disengage mechanism would see wear, but not the clutch itself.

Imagine a manual transmission vehicle, stopped with the engine not running. And you get in an depress the clutch pedal... how many times would it take to wear out the clutch face? All it is doing is pressing on the pressure plate, then retracting, no friction on the face and no associated wear. This is exactly what our transfer cases do when the clutch engages and disengages with no speed differences between the front and rear drivelines. That clutch only ever sees frictional wear when you are turning, or spinning a wheel.

Aslo, our 392s do not really see any mileage improvement by sending torque to the rear driveline. Everything in the front driveline still turns. (except maybe a small section within the transfer case before the clutch mechanism). But the front hubs, axle shafts, diff and driveshaft all spin, even in force 2wd.

 

[onfire392]

We will just have to disagree on that. You believe what you believe, I’ll believe what I’ll believe.

 

[onfire392]

I’m with ya on the rotating assembly, but the clutch wears. Material shows up in the oil, etc. Why even have a clutch ? How could the disc surface possibly wear at all….make it out of wax paper. How can there possibly be failures of the gears and the clutch at all. It’s a wear item by design or just make it a Torsen.

 

[onfire392]

Interesting transfer case reaction.

 

[V8ForMe]

That's great. Spend $100,000 on a jeep and now have to deal with possible TC issues. Well it doesn't seem to be hurting the 392 sales. Other than a total loss of warranty is anyone doing Atlas TC swaps?

 

[stumblinhorse]

That's great. Spend $100,000 on a jeep and now have to deal with possible TC issues. Well it doesn't seem to be hurting the 392 sales. Other than a total loss of warranty is anyone doing Atlas TC swaps?

Lots…

 

[onfire392]

https://www.magna.com/docs/default-source/powertrain-storyboards/4wd/product_storyboards_4wd_ultimax.pdf

 

[axhoaxho]

A guy logged the transfer case clutch torque applied with a JScan OBD2. The clutch slips easily in 4A , locks up much more ( but not 100%) in 4P. It locks 100% in 4L.

So , you burn a lot of clutch in 4A , much less burn in 4P and no burn in 4L. Pick your poison.

This ^^^^.

 

[thexr6]

I have heard the theory but has that been confirmed by someone who actually knows how the full time 4wd system works? Maybe you do but I dont.

Yeah, wish there was more info about the issue. My local dealer has no additional insight, and i am heeding advice found on this forum in another thread. I have put my 2007 JK though far more off road adventures, it has over 90k miles and have had 0 mechanical issues/breakdowns. Just regular maintenance..

 

[onfire392]

4 Auto wot TC log :

 

[onfire392]

4 Part Time TC WOT log. Interesting that it starts with a much higher clamping force at zero throttle position vs the 4A setting.

 

[rocketman]

So this thread is scary. Whats someone do on pavement that is snow covered? 4P?

 

[rocketman]

Had heard of failures due to low factory fluid levels.
Just checked my T-case fluid on 2024 and was 3/4+qt low on fluid.
Thankfully only at ~1500mi.
Rear diff was 1/3 qt low. Front diff full.
Intend to check transmission next just to be safe...

Flood checks hard on this thing? Need extra fluid in hand?

 

[Robr651]

Flood checks hard on this thing? Need extra fluid in hand?

Fluid check is simple. Slide under and remove the fill plug and check the level. It should be at or near the fill plug.

 

[rocketman]

Fluid check is simple. Slide under and remove the fill plug and check the level

Nice. Thank you. Going to give it a go