Did I Selec track the wrong thing?

[tommyp]

Ordered a Sport S with Selec track last week. I am concered now that I should have just picked up the part time case. I like the idea of AWD. I usually drive my trucks in 4 hi in snowy situations. My chevy's are ok with it I had a ford that wasn't and would bind in mixed driving. I ended up rolling it due to black ice and losing the rear end going up the hill when I was in 2wd. I would like to avoid that.

I would also like to put 37's on this truck and use it off road in the summers. Occasional moab trips not crazy off road stuff but moderate jeep trails. Should I try to get rid of the selec track asap and get a conventional case? Could I swap out the case later if I find I don't like it? I know I can mechanically but am unsure about the can bus stuff. I am used to older trucks where things didn't talk to each other.

I thought the case would lock in part time but I am not finding good answers. I guess I didn't look into it enough and now am thinking I should have maybe just got a rubicon with the better case and AWD? I thought that all of the cases were roughly the same in strength and the rubi just got the lower gears but now I have no idea.

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[ShadowsPapa]

I'll take your transfer case! I'd love to have that version.
There's a lot of lifted Grand Cherokees running around here with beeg tires on them - with a similar transfer case. How they'd handle huger tires on a JT I can't give an expert's opinion on, but they are good cases, good reputation.

 

[tommyp]

I'll take your transfer case! I'd love to have that version.
There's a lot of lifted Grand Cherokees running around here with beeg tires on them - with a similar transfer case. How they'd handle huger tires on a JT I can't give an expert's opinion on, but they are good cases, good reputation.

Yeah there are a lot of benefits. Mostly I will run around on 35's but would like the option to go bigger. If it is going to be a problem though I would like to be able to swap without having to trade the whole truck in. If it is just a one for one swap or needs driveshafts as well no big deal. I just am somewhat concerned on the heavier truck with heavy wheels if it would be an issue on the clutch mechanism.

 

[spectre6000]

You're concerned that big tires will cause problems? Unless there's some historical example I'm unaware of (another platform with a similar transfer case that had issues) with some mode of failure that's not occurring to me at the moment, I think you've got your load on the wrong side of the equal sign. I'm pretty confident that the reason the diesel can't be optioned with it is that it's torque limited. That's your key. It can only transfer so much torque. That's all on the engine side. What it's transferred to is more or less immaterial. If anything, it should be happier with larger tires because the axles are turning at a slower rate due to the same turning radius with bigger tires.

 

[tommyp]

You're concerned that big tires will cause problems? Unless there's some historical example I'm unaware of (another platform with a similar transfer case that had issues) with some mode of failure that's not occurring to me at the moment, I think you've got your load on the wrong side of the equal sign. I'm pretty confident that the reason the diesel can't be optioned with it is that it's torque limited. That's your key. It can only transfer so much torque. That's all on the engine side. What it's transferred to is more or less immaterial. If anything, it should be happier with larger tires because the axles are turning at a slower rate due to the same turning radius with bigger tires.

Yeah well the issue in my mind. (not an engineer) is that the tires are going to be heavier and harder to turn off road. The diesel is going to come with more torque but if you are constantly driving the clutches with bound up large tires and cooking the clutches that I would think be an issue. No one is saying if this transfer case can actually lock up in part time (some say there is a sleeve?) and when it does is it actually taking the clutches out of the equation. And is it strong enough. I don't care if I can swap it out easily for a part time case if I don't like it or it causes troubles. I just don't want to be stuck with something due to electronics that I can't swap out and have to sell the entire vehicle.

 

[ShadowsPapa]

Yeah well the issue in my mind. (not an engineer) is that the tires are going to be heavier and harder to turn off road. The diesel is going to come with more torque but if you are constantly driving the clutches with bound up large tires and cooking the clutches that I would think be an issue. No one is saying if this transfer case can actually lock up in part time (some say there is a sleeve?) and when it does is it actually taking the clutches out of the equation. And is it strong enough. I don't care if I can swap it out easily for a part time case if I don't like it or it causes troubles. I just don't want to be stuck with something due to electronics that I can't swap out and have to sell the entire vehicle.

Should be 4L and 4H like the others, but with the full-time option as well. So you can still off-road with them.

 

[tommyp]

Should be 4L and 4H like the others, but with the full-time option as well. So you can still off-road with them.

On paper yes. There just isn't a ton of history with this case and larger tires. It was in the liberty and the durango I think

 

[tommyp]

On paper yes. There just isn't a ton of history with this case and larger tires. It was in the liberty and the durango I think

I guess it is also stock in the 392 wrangler so that might make me less concerned. I don't think they would put it in there if there were issues with it off road and with larger tires.

 

[ACAD_Cowboy]

Just put an Atlas 4 in with a 6L80E and an LS swap and sleep well at night.

"Selec-Trac II uses a console mounted switch to control the MP3022 transfer case. The switch controls the 4WD mode with options of 2WD - 4WD Auto - N - 4WD Low. The MP3022 transfer case uses an electronically controlled clutch pack to bias torque from 100% rear to 50/50% front/rear. The transfer case has no center differential, so power can only be supplied to the front axle when the rear wheels begin to slip. In this way, the transfer case works almost identically to the NV247 transfer case used in the Quadra-Trac II system in 1999 to 2004 WJ Jeep Grand Cherokees. In 4WD Low mode, the clutch pack is locked and power flows through a 2.72:1 planetary gear set for higher torque at lower speeds. The 2018 and newer JL Wrangler comes by default with Command-Trac, but its Sahara trim can be upgraded to Selec-Trac II, marketed as simply Selec-Trac, utilizing the MP3022 transfer case."

I feel you are worrying too much about the wrong end of the horse. Not to say these fears are fantasy just saying you're investing too much fear in an issue that hasn't shown to be a problem. Any transfer case has limitations regarding input and output torque. The 392 and the diesel develop power in very different ways and both very different from the pentastar.

Also, given the diesel's ballon cost of engine PLUS required transmission, another 700ish dollars for select trac really pumps the price up nearly $7000, most folks would rather eat shit and piss blood rather than give jeep that much money.

 

[tommyp]

Just put an Atlas 4 in with a 6L80E and an LS swap and sleep well at night.

I feel you are worrying too much about the wrong end of the horse. Not to say these fears are fantasy just saying you're investing too much fear in an issue that hasn't shown to be a problem. Any transfer case has limitations regarding input and output torque. The 392 and the diesel develop power in very different ways and both very different from the pentastar.

Also, given the diesel's ballon cost of engine PLUS required transmission, another 700ish dollars for select trac really pumps the price up nearly $7000, most folks would rather eat shit and piss blood rather than give jeep that much money.

I wish it was that easy to drop an LS in. I have done a few. Run a terminator setup on my squarebody.

If atlas was out with their case and it worked in a selec trac than I wouldn't worry at all. Or if I could swap back to a part time only. I guess I will deal with that when the time comes I just don't want something that is going to strand me somewhere because the clutch packs get overheated with larger tires then have no other options.

I have built a few trucks (no jeeps) and sometimes making assumptions on parts can come back to bite you. This is a pretty big outlay that I will have for a while so I am just more concerned than normal.

 

[WXman]

Is the Command-Trac t-case used in the JT the NV241 that has been used for many years? Or is it that new t-case made by Magna International that they put in the Jeep Liberty KK?

 

[tommyp]

Is the Command-Trac t-case used in the JT the NV241 that has been used for many years? Or is it that new t-case made by Magna International that they put in the Jeep Liberty KK?

The new mp3022

- looks like someone swapped a rubicon case in a JL sport and it wasn't an issue with the computers the tazer I guess can change what is needed. I don't mind swapping stuff if I have to as long as the computers are happy.

 

[WXman]

The new mp3022

- looks like someone swapped a rubicon case in a JL sport and it wasn't an issue with the computers the tazer I guess can change what is needed. I don't mind swapping stuff if I have to as long as the computers are happy.

No the Magna 3022 case is a full-time AWD case that they're calling "Selec-Trac" these days. I was asking about the standard Command-Trac case. There's the old fashioned NV241 and then there's a new Magna case that has a 15XX model number. I know that the old NV241 case is CHAIN driven and very reliable. I can't comment on the newer MP15XX case.

 

[spectre6000]

I have two trucks in my driveway right now with a New Venture transfer case using this technology. One is behind a 2.8L Duramax, the other is behind a 5.7L SBC (and 22 years old). I've never had any issues with either. I'm not a Jeep (or any make) guy, so I'm not completely familiar with what Jeep has used in what and when, but I know Chevy has been using this tech since at least the late 90s, and it's not (to my knowledge) a known problem spot. It's going to be slightly different for Jeep, but from my research into diesel tuning with the Duramax, I recall either the transmission or the transfer case was torque limited to 400 ft lbs or something like that (the tune made more, and thus became a dubious proposition). It's notable that the 4hi Auto is not available with the diesel, and my suspicion is because the diesel makes too much torque. That it is available with the V8 (according to previous comments here), may cast some doubt on that assessment (I haven't looked into it at all).

Bigger tires will require more torque to turn, but the engine is only capable of so much, and the tires can't do anything about it. Additionally, with the 4:1 ratio on the Rubicon, you've got a lot of multiplication going on there. Probably netting out to more torque than the diesel makes on its own. Either it's completely taken the clutches out of the equation, or they can handle it, just not with the transfer case gear multiplication. The Wrangler is Jeep's/FCA's/Stallantis's biggest cash cow. They can not afford to screw it up. I'm positive it's been tested thoroughly.

 

[aldo98229]

I have Selec-Trac in my Sahara: I absolute love it!

Selec-Trac works like two systems in one:

1. In full-time mode Selec-Trac is ideal for constantly changing winter driving conditions. The system engages and disengages instantly and seamlessly. With the rear LSD, it makes the Jeep virtually unstoppable in snow.
2. In part-time mode Selec-Trac works just like your regular Jeep transfer case, with 4H and 4L, locking the front and the rear 50/50 at the center.

One word of caution: don’t forget to engage into part-time mode as soon as you hit the trailhead; this prevents the clutch pack from overheating. Don’t ask how I know...

At only $600, Selec-Trac is one of the biggest bargains on Jeep’s options list IMO.

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