392 Atlas transfer case install

[Some Random Guy]

The rotation of the case can help the front driveline angle, but it doesn‘t change the rear at all. It pivots on the axis of the rear shaft output. In my application, my rear driveline will have to be shortened over 4”. On the 3.6’s, I think it stays close to the same, based on Advance’s statements (but I‘be found them to be wrong many times now).

Thank you. So the rear driveshaft is in line with the transmission output? Then the front output is offset, allowing rotation to relieve front driveshaft angle?
I haven’t watched any videos, only briefly reviewed the install instructions to see if I could handle it on my own.

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[1996cc]

Yep. Motor crankshaft, straight into transmission, straight through transfer case, down rear driveline…

 

[BeechAV8R]

Thanks for taking one for the team and doing AA's r&d.

 

[Old Jeeper]

Yep. Motor crankshaft, straight into transmission, straight through transfer case, down rear driveline…

Is this the reason why you went with the Atlas? If not what was your justification vs the OEM 4:1?

I have considered it seriously but when it came down to it and I talked with Atlas and other that switched I just could not justify the $$$$, albeit Atlas is not just good, its GREAT!!! Truly superior in design, but the 241 is bulletproof itself, maybe the Atlas is a BIGGER caliber of bullet proof.

I went back and forth for years on this subject. $ was never a question, but results are my driving force, its how I run/ran my companies. I just could not find a delta large enough between the Atlas and the 241 that would make me switch..

I would appreciate your comments, you clearly know what you are doing...thank you.

 

[1996cc]

Is this the reason why you went with the Atlas? If not what was your justification vs the OEM 4:1?

I would appreciate your comments, you clearly know what you are doing...thank you.

Biggest reason is to get the Jeep computer out of my transfer case. The 392 is awd and engages 4wd with clutches. Clutches easily fail. And it was deciding when it did or didn’t want to be in 4wd, no matter where the shifter was. I was losing power to front under heavy throttle. And recently it hasn’t wanted to come out of part time 4wd ?

I went with a 3.0:1 ratio because of all the torque the hemi has. Factory ratio is 2.72:1, so I’ll essentially be the same. I’ve already wheeled this all over Moab (including Prichett), and it’s plenty low geared already.

I will also enjoy the front dig ability. Using front wheel drive only, combined with the Tazer’s trail turn assist, will allow me to weave through the trees here in the Northwest like a ninja ?

 

[blnewt]

Very cool that you're the pioneer for this adaptation, nice job detailing everything. It seems like you're plenty capable to do what you need to complete the Advance Adapters engineering. They should give you some R&D kickbacks or at least some cool Jeep swag for your efforts

 

[Old Jeeper]

Biggest reason is to get the Jeep computer out of my transfer case. The 392 is awd and engages 4wd with clutches. Clutches easily fail. And it was deciding when it did or didn’t want to be in 4wd, no matter where the shifter was. I was losing power to front under heavy throttle. And recently it hasn’t wanted to come out of part time 4wd ?

I went with a 3.0:1 ratio because of all the torque the hemi has. Factory ratio is 2.72:1, so I’ll essentially be the same. I’ve already wheeled this all over Moab (including Prichett), and it’s plenty low geared already.

I will also enjoy the front dig ability. Using front wheel drive only, combined with the Tazer’s trail turn assist, will allow me to weave through the trees here in the Northwest like a ninja ?

WOW, I did not expect that answer, I had no idea the 392 operated like that. Makes good sense.

Which is why the TJR would be my pick if I were to do another build, no tricks, gimmicks, electrons all over the place and you not knowing what going on.

Good on ya for sure and thank for the reply. So have you done Prichett forward and back by yourself and never pull your winch or a strap to help. Albeit I had do so before, that was last run in Moab, I retired from rocks after a nearly 10 year run...I sold my company, wife asked what I was going to do and I said we are moving to Scottsdale AZ and I am going to feed my 40+ year passion of wheeling from Utah to Mexico and Texas to Cali and we moved to Scottsdale to be centraly located.

 

[Kindapointless]

So random question but what are your plans for the old case? I have been looking for a dead one for autopsy and measurements

 

[1996cc]

After emailing the sales manager at Advance all of the pics I posted last night, their CEO called me this morning (Sales Manager is out). They have 3 factory rubber crossmember mounts and they are all different from each other and different than the 392s. I gave him my part number, so they have one of those coming now to work with. In the meantime, he didn’t want me to have cut mine up too much. He is overnighting me one of the other OEM mounts they had so that I can get my install finished up this weekend. In his words, “you’ve waited long enough, and customer service is everything.” Hallelujah! You can’t argue with that!

I didn’t make much progress tonight, just assembled the shifter assembly. I should be able to work on it most of the day tomorrow and hopefully have a significant update tomorrow night.

 

[Bzinsky]

Just an FYI, as you probably know the 4xe shares a lot of drivetrain with the 392. Same transfer case, axles, diffs, and trans (well some of the trans is different)

I believe the 4xe trans is a little bit longer because of the hybrid stuff, and I believe the front driveshaft is longer and the rear driveshaft is shorter than the 392. Not sure if they would fit. Just throwing it out there incase it helps.

 

[1996cc]

Did a fair amount today, still a fair bit to do (and redo ?). Advance came through and had the new factory mount here as promised.

Shifters in place inside. Grommet not yet reinstalled in this pic.

Advance doesn’t address this, but in order for the computer to not get cranky over not having a transfer case clutch to manage, you have to swap out the Transfer Case Control Module (DTCM). This is somewhat of an unknown, but Tyler of Rock Solid Fab and Scott Blum of Jeep have both told me that it is needed. It may be possible to just completely turn off the DTCM with the Tazer (that’s what Dixie 4x4 has been doing), or leave it plugged in and hang the clutch motor somewhere to make it think it’s working properly (what Off Road Evolution/EVO is trying). Both of them have been experimenting with mating a sport case with a 392 case to remove the clutches. Anyway, I ordered a new DTCM (model year specific) for a non-392 2021 Rubicon.

I found a random diagram online that gave me an idea where this is located, and fortunately it was correct. It is tucked behind the passenger rear roll bar.

While I was this deep in, I also ran some wiring for a rear dust light. That sucked a bunch of time going through the tailgate, etc…

Advance even included some personalized instructions with the new mount. That was kinda nice ?

The two mounts together, differences are pretty obvious. As the instructions stated, the mount is taller, so I left out the 1/2” adapter (more on that later…)

Everything all mostly in place. Just waiting on my driveline to return from Tom Woods. You can also see that I moved the site tube to the other side to get it further away from the exhaust heat.

New and extra wiring tucked up. Near the bottom left of the photo, you can see I mounted the Atlas module to the factory roost shield in front of the fuel tank.

The module wiring needs power from the fuse box. Advance includes the fuse tap at bottom. It’s clearly the wrong size for JL fuses, so I picked up a proper one.

To end the day (it was like 8:00pm), I was going to throw on my Metalcloak skid and be mostly done underneath the Jeep. At that point, I realized that I still need the adapter spacer. The drivetrain must be 1/2” lower, because the skid plate hits the exhaust crossover tube before the skid gets to the crossmember. ? To be continued another day…

 

[1996cc]

Got the adapter in this morning. I had to notch one of the holes in the factory mount to match the tapped hole in the Atlas adapter. I’m sure Advance will modify their design of these once they get my updates. Skid plate now clears the crossover pipe like it should.

Here’s the pile of now unused factory parts, and the Atlas pieces that I didn’t use (except the 2 little tapered head screws are for the shift knobs).

I also finished up the wiring, ran the vent tube, and put the console back in. Nothing really picture worthy. One note on the vent tube that my buddy Ryan figured out- It is an easy way to fill the Atlas in the future! There is no fill plug on these, you have to remove the upper site tube plug and pump it in. (They even tell you to fill it from the drain plug before the initial install). Therefore I ran the vent tube to an easily reached spot in the engine bay. And I plan to install a filter on the top to keep it clean. When filling this way, it’s still best to crack the upper site tube plug to allow air to vent out. I also plan to cut a hole in my factory transfer case skid directly below the new drain plug.

My daughter had a soccer game, so the day was cut short. Tomorrow I hope to finish up some unrelated wiring and get the computer programmed for the new DTCM with the AlphaOBD software. Then I plan a small test drive on my property (in front wheel drive only since I don’t have a rear driveline yet)

 

[1996cc]

I did the computer stuff today. And things appear to be working well. I’ve never dealt with the AlphaOBD software and I had no idea what I was doing. I used a Vgate vLinker with cables to plug it into the SGW ports (same place the Tazer plugs in) and connected to that via bluetooth with my Windows laptop. First I unmarried the Tazer (I have no idea if that was needed, but it’s what I did). Once I got the AlphaOBD software to connect to the Jeep, I spent close to 30 minutes fiddling around with the software to try and figure out what I was doing.

Under the “Active Diagnostic” tab, I then selected “Car Configuration Change” and then searched for Transfer Case. That brought up this list of options. I chose 241 (it was set for 246), and just clicked next.

Once I was done, under the main menu, I read the system status (or ID, I can’t remember) again and scrolled down and can see that is shows correctly in there now as well (it showed 246 before)-

Once that was complete, I cycled the ignition and then remarried the Tazer and reconfirmed all my settings there as well as changing the Tcase ratio to 3.030 as directed for the Atlas. I had to clear the fault codes twice and do the two Tazer sleep cycles.

Then I did a short test drive at my house in front wheel drive (I still don’t have a rear driveline). Everything appears to work as designed and there where no weird dash lights when I put it back in the shop ??

Tom Woods should be calling tomorrow to confirm driveline specs (my old one landed at their shop Saturday), and I’ll likely have it back before the end of the week. Unfortunately (and fortunately), I leave Saturday for a Sprint Break vacation. Hopefully I’ll get to drive it officially before we leave town, I’m definitely anxious to!

One other minor detail I need to finish up is the shifter boot. Advance provides a good option to reuse the factory one, with decent instructions. I still need to do that, but not in a huge rush. (So I won’t have the top stickers on the shift knobs until that’s done.) I’m also waiting on new blocks and barrel nuts for the shift cables from Advance. Mine were not the proper tolerance, but I made them work for now. Once I have those, I will also adjust them to make the shifters line up more evenly.

 

[Proptrash]

I did the computer stuff today. And things appear to be working well. I’ve never dealt with the AlphaOBD software and I had no idea what I was doing. I used a Vgate vLinker with cables to plug it into the SGW ports (same place the Tazer plugs in) and connected to that via bluetooth with my Windows laptop. First I unmarried the Tazer (I have no idea if that was needed, but it’s what I did). Once I got the AlphaOBD software to connect to the Jeep, I spent close to 30 minutes fiddling around with the software to try and figure out what I was doing.

Under the “Active Diagnostic” tab, I then selected “Car Configuration Change” and then searched for Transfer Case. That brought up this list of options. I chose 241 (it was set for 246), and just clicked next.

Once I was done, under the main menu, I read the system status (or ID, I can’t remember) again and scrolled down and can see that is shows correctly in there now as well (it showed 246 before)-

Once that was complete, I cycled the ignition and then remarried the Tazer and reconfirmed all my settings there as well as changing the Tcase ratio to 3.030 as directed for the Atlas. I had to clear the fault codes twice and do the two Tazer sleep cycles.

Then I did a short test drive at my house in front wheel drive (I still don’t have a rear driveline). Everything appears to work as designed and there where no weird dash lights when I put it back in the shop ??

Tom Woods should be calling tomorrow to confirm driveline specs (my old one landed at their shop Saturday), and I’ll likely have it back before the end of the week. Unfortunately (and fortunately), I leave Saturday for a Sprint Break vacation. Hopefully I’ll get to drive it officially before we leave town, I’m definitely anxious to!

One other minor detail I need to finish up is the shifter boot. Advance provides a good option to reuse the factory one, with decent instructions. I still need to do that, but not in a huge rush. (So I won’t have the top stickers on the shift knobs until that’s done.) I’m also waiting on new blocks and barrel nuts for the shift cables from Advance. Mine were not the proper tolerance, but I made them work for now. Once I have those, I will also adjust them to make the shifters line up more evenly.

Very nice write up. Glad the Dtcm is working and hoping it works in the long run. I believe it’s the best solution. Even for folks that want to use the guts of a regular jeep part time trans case stuff them into the 392 trans case.

 

[1996cc]

Very nice write up. Glad the Dtcm is working and hoping it works in the long run. I believe it’s the best solution. Even for folks that want to use the guts of a regular jeep part time trans case stuff them into the 392 trans case.

Yes, any transfer case option that removes the factory clutches will have to do this.

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