Why the 392 doesn't need Rubicon transfer case?

[Ratbert]

i also have the EcoD with 37s and 4.56s, and specifically did not want the 4:1 t'case of the Rubicon. (it's one of several reasons i ordered a Willys instead of a Rubicon on which to do my build.)

even with the powerplant in stock trim, with the automatic ZF and it's torque convertor, the abundant low-RPM torque of the diesel does a pretty fine job in the rocks, and with the 2:7.2 t'case i'm not wound out if running 4Lo between sections.

Make sure to avoid trails like Red Cone. I've seen Sports lose their brakes there due to that transfer case.

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[zouch]

well, as someone who once lived in Colorado, i'm sure you know not everyone knows how to use their brakes.

i'll take my chances.

Make sure to avoid trails like Red Cone. I've seen Sports lose their brakes there due to that transfer case.

 

[roaniecowpony]

I think it's likely the 392 presented the designers with some challenges. Buyers expect the 392 JL to be fast/quick on the street yet, apparently, they wanted to stick with the M210/M220 axles. I think the decision to stick with the M210/M220 axles and the "need for speed", drove the requirement to use "all wheel drive", so the torque was dispersed into both axles during street use while still not limiting the engine too badly with torque management. Don't all wheel drive transfer cases all have clutches?

 

[Riverjeep]

And this is why AI is damn near useless. The AWD transfer case is the weakest factory case available. The clutches fail, especially wheeled hard behind the 392. I agree the 392 doesn't need the 4-1 because of is torque output, but it would be more durable with the standard part time transfer case.

Ok now I’m gonna be ignorant because my understanding is the clutches were only in play if you leave it in 4 auto. If you place it in 4 high or 4 low you no longer are using the clutch packs. In other words only use 4 auto for highway use. Is this not the case? The AI I posted even refers to using the AWD on pavement.

 

[Gorilla57]

And this is why AI is damn near useless. The AWD transfer case is the weakest factory case available. The clutches fail, especially wheeled hard behind the 392. I agree the 392 doesn't need the 4-1 because of is torque output, but it would be more durable with the standard part time transfer case.

What's funny, is that at the end of 2023, there was a member on here that swore up and down that the 392 t-case clutches were locked and wouldn't slip. Now that there has been numerous failures, the point is proven that the clutches do slip and fail, losing output to the front axle.

 

[Snacktime]

Clutch based transfer cases are the cheapest way to put AWD on the sales brochure. 4wd is now the lesser option to most buyers even in the offroad world.

 

[Zandcwhite]

Ok now I’m gonna be ignorant because my understanding is the clutches were only in play if you leave it in 4 auto. If you place it in 4 high or 4 low you no longer are using the clutch packs. In other words only use 4 auto for highway use. Is this not the case? The AI I posted even refers to using the AWD on pavement.

The clutches are always involved in transmitting power to the front shaft. They are supposed to lock in 4HI and 4LO. The problem is once they start to wear and slip, they'll slip even when locked. I'll pass on adding an additional failure point that will lead me to effectively having a 2wd Jeep on a tough trail just so I don't have to shift into 4wd myself under mixed road conditions.

 

[Zandcwhite]

I think it's likely the 392 presented the designers with some challenges. Buyers expect the 392 JL to be fast/quick on the street yet, apparently, they wanted to stick with the M210/M220 axles. I think the decision to stick with the M210/M220 axles and the "need for speed", drove the requirement to use "all wheel drive", so the torque was dispersed into both axles during street use while still not limiting the engine too badly with torque management. Don't all wheel drive transfer cases all have clutches?

For the most part yes, but how many Subarus and Audis do you see on the rubicon?

 

[EbyCreek]

My 392 only made it to 11,000 miles before the clutches went out. I put in a 3:8 Atlas, one of the best upgrades I’ve done.

 

[Riverjeep]

The clutches are always involved in transmitting power to the front shaft. They are supposed to lock in 4HI and 4LO. The problem is once they start to wear and slip, they'll slip even when locked. I'll pass on adding an additional failure point that will lead me to effectively having a 2wd Jeep on a tough trail just so I don't have to shift into 4wd myself under mixed road conditions.

Gotcha, thanks.

 

[Sportacus]

Jeep Master Tech Jerry that appeared on TrailRecon's channel told me he will swap our transfer cases for $900. I just have to make it to Southern California.

jeep master tech jerry also had my Sport for a month and couldnt figure out how to install the rubicon TC i had. Said coulnt be done with out doing a full custom install job. I did come home with a nice free door ding though, no charge.

 

[Jeep Junkie]

jeep master tech jerry also had my Sport for a month and couldnt figure out how to install the rubicon TC i had. Said coulnt be done with out doing a full custom install job. I did come home with a nice free door ding though, no charge.

 

[AmericanPatriot100]

jeep master tech jerry also had my Sport for a month and couldnt figure out how to install the rubicon TC i had. Said coulnt be done with out doing a full custom install job. I did come home with a nice free door ding though, no charge.

That’s interesting because @SadRobot just installed a rubicon tcase on her 2dr sport not too long ago.

 

[Zandcwhite]

The Jeep tcase is super easy to swap/ install. Anybody with a basic wrench set that can install an alternator should be able to figure it out. I do believe that the auto and manual tcases are different, so maybe that was the problem?

 

[SadRobot]

That’s interesting because @SadRobot just installed a rubicon tcase on her 2dr sport not too long ago.

Yeah why the shop told him it wouldn't fit will remain a mystery we won't solve until @Sportacus and I eventually install his transfer case. If I remember correctly the shop told him the splines wouldn't line up?

I also had some interesting conversations with shops about a t-case swap. A lot said it couldn't be done, just flat out wouldn't do it or craziest convo I had was a local shop quoted me 5k to install and said it would take them a week.

Mine was actually in a shop for a week while they tried to install a t-case they found that they claimed was for a manual. They tried 2 different t-cases before giving up and putting my sport t-case back in. At least they did not charge me for any of that work.

In the end I did it in my driveway in a weekend. From start to finish I'd say for me it was 14ish hours of labor since I had no experience and took time checking the forum thread write up. Plus I broke off the heads on my driveshaft bolts which was a setback. With a shop, lift and power tools I would imagine it should be 5-6 hours of labor.

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