command trac ll

JeepinJarhead03 · **Posted:** Thu Dec 30, 2010 2:02 am

If someone truly wants "4Lo" on a hard surface, they're wanting it for the grunt of the reduced gearing, with a functioning LSD in the rear and or traction control, one of the two available 2Lo modifications would be more along the lines of what they need, rather than what they're actually doing

2Lo naturally would come in handy in a variety of offroad application as well so would be a multipurpose investment

I'm of course saying this assuming it's available for the KKs, if it's not, push them to make it avail.

rockwerks · **Posted:** Thu Dec 30, 2010 2:06 am

So how does the comand trac differ from an XJ np231? or np242 transfercase? and BTW Moab Slick Rock is far from being Slick! IVe been there many times and in most cases has much higher traction than asphalt

JeepinJarhead03 · **Posted:** Thu Dec 30, 2010 2:20 am

231 is the command trac ie: Only Part time, the 242 has a center differential, operates in both full or part time, full time = basically AWD style 4wd which is considered center differential open, with the center differential locked, it's locked by a set of clutches which causes it to behave similar to the manner in which the 231 locks the front and rear driveshafts in unison, operate the 242 locked on high traction surface you end up with the same scenario as a 231, a damaged transfer case, however in the 242's full time selection, you can drive it with superglue tires on velcro asphalt if you want

the 242 is basically a flexible crossover system that tries very hard to give you the benefits of both systems

if you want a graphical demonstration, jeep's website has a pretty good one

http://www.jeep.com/en/4x4/how_systems_ ... ec_trac_2/

rockwerks · **Posted:** Thu Dec 30, 2010 3:05 am

JeepinJarhead03 wrote:

231 is the command trac ie: Only Part time, the 242 has a center differential, operates in both full or part time, full time = basically AWD style 4wd which is considered center differential open, with the center differential locked, it's locked by a set of clutches which causes it to behave similar to the manner in which the 231 locks the front and rear driveshafts in unison, operate the 242 locked on high traction surface you end up with the same scenario as a 231, a damaged transfer case, however in the 242's full time selection, you can drive it with superglue tires on velcro asphalt if you want

the 242 is basically a flexible crossover system that tries very hard to give you the benefits of both systems

if you want a graphical demonstration, jeep's website has a pretty good one

http://www.jeep.com/en/4x4/how_systems_ ... ec_trac_2/

Thanks for the link

I have run thousands of miles on both the NP242 and NP231 in Cherokees in very high traction situations locked at both axles in mostly 4LO, as have thousands of other Cherokee and Wrangler owners and seldom do you see any transfer case damage.

I have always installed a 242 in my wives XJ's as she drove it on the highways of Northern AZ for work and the high speed 4x is wonderful safety item for her.

JeepinJarhead03 · **Posted:** Thu Dec 30, 2010 3:39 am

Well, not to avoid fully answering your question, but there's an additional difference between the XJ setup and the KJ/KK setup since the front diffs are different and the gears are not interchangeable between the XJ 30s and the KJ/KK 30s

i've pulled a couple xj cases that failed for various reasons, one of them being it stuck, didn't disengage after leaving the beach and they didn't realize it

it's got a bit to do with the differences in your tire's front/rear which when going straight can either ease the issue if the front tires are worn more than the rear or make it worse if the front tires are worn less than the rear. Most wranglers with the 231 and 33x11'ish hwy/trail tires you can engage part time 4wd in a gravel ontop of pavement parking lot like what's found behind many hotels and such at the coast, turn the wheels about halfway to either direction while going a few mph and it'll start binding and popping

the ctrac's aren't a very "Convenient" system, but they weren't meant to be "Convenient". It's rare to bust the case, the shafts are known to be one of the weaker components, and our 231s are narrow chain, but it would/should be possible to upgrade them to the wide chain with the right swap parts.

but that's sort of besides the point, there's nothing inherently wrong with the CT system and it will accept much more abuse than the 242 will when used incorrectly but just because it can take some abuse doesn't mean it isn't damaging it

and it's not really one of those If's, it's a When

the wide chain, which is a somewhat common swap on the XJ's is the 231HD or DHD, and the output shafts on the standard 231J is known to be fairly weak and isn't an uncommon part to upgrade or uncommon failure

differences in the 231 and 242 used in XJ's and the ones used in KJ's and KK's are rather un-noteworthy with most of the technical differences involving the vacuum disconnects found on mostly YJ's and such in terms of the 231 and whether or not certain variants have actual true neutral for being towed etc

as far as the specific differences between KK and XJ 242s or 231's, my statement would be that there isn't enough difference for it to make a difference. there's some spline and shaft differences depending on what they mate to and such but a 231 or 242 is still that, a 231 or 242 and maintains the inherent issues associated with each

one has clutch/fragility of the intermediate differential, and the other has driveline binding issues on high traction surfaces, either way they're both good systems when used properly, but when used improperly will eventually hit you in the wallet

I'm sure troy will volunteer to divulge specific differences in those transfer cases for you tomorrow, but for the actual specifics, I can't offer you too much other than tell you what people were doing right before they paid me to fix it

Matt_ · **Posted:** Thu Dec 30, 2010 6:40 pm

There's a HUGE difference in driving 70 miles down a highway in 4 Hi, or driving a few miles towing a boat and making sharp turns in 4 Hi as opposed to what i am saying.

You're not going to blow up your drivetrain at a boat launch or pulling someone out of a ditch, or driving 20 feet in a straight line.

Hell, you can IDLE forward down the street in 4hi. If you tell me that putting a CT2 Jeep liberty in 4x4 and letting the foot off the brake and IDLING forward is going to break the tailshaft, then these are the worst designed systems in the world and im surprised they're not broken down all over the road.

I am not advocating turning, driving long distances or at high speeds in 4HI or 4LO. But if you need the grunt to get your buddy out of a ditch or if you need it to get that boat out of the water, it'll work perfectly fine. Remember, that was the question.

garrobb wrote:

but say i wanted to pull someone out of the ditch and i'm on dry pavement

If you disagree, that's fine. You're entitled to your opinion too. :2cents:

rockwerks · **Posted:** Thu Dec 30, 2010 6:50 pm

Matt_ wrote:

There's a HUGE difference in driving 70 miles down a highway in 4 Hi, or driving a few miles towing a boat and making sharp turns in 4 Hi as opposed to what i am saying.

You're not going to blow up your drivetrain at a boat launch or pulling someone out of a ditch, or driving 20 feet in a straight line.

Hell, you can IDLE forward down the street in 4hi. If you tell me that putting a CT2 Jeep liberty in 4x4 and letting the foot off the brake and IDLING forward is going to break the tailshaft, then these are the worst designed systems in the world and im surprised they're not broken down all over the road.

I am not advocating turning, driving long distances or at high speeds in 4HI or 4LO. But if you need the grunt to get your buddy out of a ditch or if you need it to get that boat out of the water, it'll work perfectly fine. Remember, that was the question.

garrobb wrote:

but say i wanted to pull someone out of the ditch and i'm on dry pavement

If you disagree, that's fine. You're entitled to your opinion too. :2cents:

Im with you, If the TC grenades on high traction areas you would not be able to use them in MOAB on slick rock at all.

Matt_ · **Posted:** Thu Dec 30, 2010 6:55 pm

rockwerks wrote:

Im with you, If the TC grenades on high traction areas you would not be able to use them in MOAB on slick rock at all.

Exactly.

NOT THAT YOU SHOULD use it in high traction areas. But there are times, like the OP asked about, in which it's "OK" to use it on occasion if needed. Point is, it's not going to blow up in a few feet.

Continued misuse however, like some examples people have posted in this thread, you'll be replacing parts. Pulling a friend out of a ditch a few times in the life of the vehicle or recovering a boat a few times a year is not going to have a notable effect on the life of the drivetrain. (Edit: IMO of course)

rockwerks · **Posted:** Thu Dec 30, 2010 7:03 pm

Matt_ wrote:

rockwerks wrote:

Im with you, If the TC grenades on high traction areas you would not be able to use them in MOAB on slick rock at all.

Exactly.

NOT THAT YOU SHOULD use it in high traction areas. But there are times, like the OP asked about, in which it's "OK" to use it on occasion if needed. Point is, it's not going to blow up in a few feet.

Continued misuse however, like some examples people have posted in this thread, you'll be replacing parts. Pulling a friend out of a ditch a few times in the life of the vehicle or recovering a boat a few times a year is not going to have a notable effect on the life of the drivetrain.

Like I said earlier I have thousands of miles on Xj's with 231 cases, locked front and rear on on very high traction situations, I have broken U joints in drive shafts but never any TC parts. I think most of it has to do with the amount of use of the skinny pedal, Flogging it will always end up with broken parts.

At The Helm · **Posted:** Fri Dec 31, 2010 1:14 am

JeepinJarhead03 wrote:

If someone truly wants "4Lo" on a hard surface, they're wanting it for the grunt of the reduced gearing, with a functioning LSD in the rear and or traction control, one of the two available 2Lo modifications would be more along the lines of what they need, rather than what they're actually doing

2Lo naturally would come in handy in a variety of offroad application as well so would be a multipurpose investment

I'm of course saying this assuming it's available for the KKs, if it's not, push them to make it avail.

What is this 2lo mod you speak of?

JeepinJarhead03 · **Posted:** Fri Dec 31, 2010 1:19 am

Currie and Terra both make 2Lo kits for the 231's, it's 2wd Lo, same gearing as 4Lo without engaging the front axle, also allows for disconnection of the front axle for turning purposes without migrating back through N and 4Hi to 2wd

tjkj2002 · **Posted:** Fri Dec 31, 2010 8:51 am

JeepinJarhead03 wrote:

Currie and Terra both make 2Lo kits for the 231's, it's 2wd Lo, same gearing as 4Lo without engaging the front axle, also allows for disconnection of the front axle for turning purposes without migrating back through N and 4Hi to 2wd

Just to bad the KK does not use a 231,or a 242.

rockwerks · **Posted:** Fri Dec 31, 2010 10:19 am

tjkj2002 wrote:

JeepinJarhead03 wrote:

Currie and Terra both make 2Lo kits for the 231's, it's 2wd Lo, same gearing as 4Lo without engaging the front axle, also allows for disconnection of the front axle for turning purposes without migrating back through N and 4Hi to 2wd

Just to bad the KK does not use a 231,or a 242.

correct the command tracII is the mp1522 and select trac is mp3022

Matt_ · **Posted:** Fri Dec 31, 2010 10:40 am

rockwerks wrote:

tjkj2002 wrote:

JeepinJarhead03 wrote:

Currie and Terra both make 2Lo kits for the 231's, it's 2wd Lo, same gearing as 4Lo without engaging the front axle, also allows for disconnection of the front axle for turning purposes without migrating back through N and 4Hi to 2wd

Just to bad the KK does not use a 231,or a 242.

correct the command tracII is the mp1522 and select trac is mp3022

How does the mp1522 engage the front axle?

Back in the day I used to wheel a 98 explorer. The T-case in that used an electronic clutch to engage the front drive shaft. One of the guys I used to wheel with, who was an electrical engineer, came up with an relay/switch to splice in which allowed us to control front axle engagement. We were then able to put the trucks in 4Low and disengage the front... thereby giving is 2Low.

It really is great having 2Low. I wonder if a similar setup would work for the Liberty....

rockwerks · **Posted:** Fri Dec 31, 2010 11:33 am

Matt_ wrote:

tjkj2002 wrote:

JeepinJarhead03 wrote:

Currie and Terra both make 2Lo kits for the 231's, it's 2wd Lo, same gearing as 4Lo without engaging the front axle, also allows for disconnection of the front axle for turning purposes without migrating back through N and 4Hi to 2wd

Just to bad the KK does not use a 231,or a 242.

How does the mp1522 engage the front axle?

Back in the day I used to wheel a 98 explorer. The T-case in that used an electronic clutch to engage the front drive shaft. One of the guys I used to wheel with, who was an electrical engineer, came up with an relay/switch to splice in which allowed us to control front axle engagement. We were then able to put the trucks in 4Low and disengage the front... thereby giving is 2Low.

It really is great having 2Low. I wonder if a similar setup would work for the Liberty....

Looking at the exploded view it is internally almost Identical to the NP231 so a 2lo would be theoretically possible but Im betting the 231 parts would not work

JeepinJarhead03 · **Posted:** Fri Dec 31, 2010 5:29 pm

I'd give terra or currie or both a poke, and "enhance" their notions that the 1522 needs a 2Lo kit, problem would be if the MP uses an electronic switch on the dash..

which.. it does right? or does it still have a stick?

rockwerks · **Posted:** Fri Dec 31, 2010 8:13 pm

JeepinJarhead03 wrote:

I'd give terra or currie or both a poke, and "enhance" their notions that the 1522 needs a 2Lo kit, problem would be if the MP uses an electronic switch on the dash..

which.. it does right? or does it still have a stick?

electric switch. but could still be done

Matt_ · **Posted:** Fri Dec 31, 2010 8:22 pm

rockwerks wrote:

JeepinJarhead03 wrote:

I'd give terra or currie or both a poke, and "enhance" their notions that the 1522 needs a 2Lo kit, problem would be if the MP uses an electronic switch on the dash..

which.. it does right? or does it still have a stick?

electric switch. but could still be done

x2

It's just a matter of figuring out what signals are sent where and how to interrupt them safely without throwing any codes while allowing 4low to engage but the front driveshaft/differential to not engage. That's basically what we did with our explorer which was electronically controlled.

tjkj2002 · **Posted:** Fri Dec 31, 2010 9:06 pm

rockwerks wrote:

Looking at the exploded view it is internally almost Identical to the NP231 so a 2lo would be theoretically possible but Im betting the 231 parts would not work

2 completely different company's making the KJ's and KK's t-cases so the parts will not interchange and since the KK is the only one using those t-cases I highly doubt either TerraFlex or Currie will even bother since the KK is doomed anyways in a few years.

rockwerks · **Posted:** Fri Dec 31, 2010 9:37 pm

tjkj2002 wrote:

rockwerks wrote:

Looking at the exploded view it is internally almost Identical to the NP231 so a 2lo would be theoretically possible but Im betting the 231 parts would not work

2 completely different company's making the KJ's and KK's t-cases so the parts will not interchange and since the KK is the only one using those t-cases I highly doubt either TerraFlex or Currie will even bother since the KK is doomed anyways in a few years.

There are some things that have me turned off on the KK, these TC's are part of it. maybe a grand Cherokee is in my future or an older JK. I knew that parts would not interchange but knew it could be done

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