Jump to content

242 vs 231


Recommended Posts

so i have the 231 t case and i was wondering if the 242 with the high loc and the low loc was worth swapping in and weather or not it would be a direct bolt in. would one from a xj bolt right into my mj. i know i wouldnt have the indicator light but what woudl i all need to put one in.. or woudl i have lights if i just got the screen for the cluster and then just put in the bulbs? thanks

Link to comment
Share on other sites

I have had both and run my 242 case if fulltime 99% of the time. I prefer the handling of the 242 case it's is great in snow and rain. It also corners better and is great for getting out in traffic on dry pavement too.

 

I might see about swaping a 242HD from a Dodge Durango I just found, it would have the wider chain and some other stronger parts. I'd like to find out what is differend between the Dodge one and the Hummer H1 model.

Link to comment
Share on other sites

The difference between the cases is the 242 offers an "AWD" mode (Full time) and has a central differential. It has limitatons.

Correct. The 231 has a locking 4-High and 4-Low range. So does the 242. If the original poster is referring to the full-time (all wheel drive) mode, yes the 242 adds that to the mix. It is also marginally weaker than the 231, but in all the outings I've been to with NAXJA I never saw anyone break a 242, so I wouldn't consider it to be a weak sister.

 

Keep in mind that the MJ probably has a disconnect front axle. The 242 does not use a disconnect axle and I don't think it has a vacuum port to control it. So to swap in a 242 you would also have to either rig a control (vacuum or manual) for shifting the axle disconnect, or just shim the disconnect into the engaged position and leave it there.

Link to comment
Share on other sites

Anyone know the overall length difference between a 242 and 231? I was thinking of swapping a 242 into my kids truck before winter. The truck already has a non disconnect front axle, so the vac junk could be completly removed. Just would need to run wires for the 4wd indicators.

Link to comment
Share on other sites

The 231 has : 2WD high, 4WD high (part time) and 4wd Low (part time)

242 has: 2WD high, 4wd high (fulltime), 4WD high (part time) and 4wd Low (part time)

In the above, "part time" is Jeep's terminology for "locked." So your 231 has 4-wheel-drive locked high range and 4-wheel-drive locked low range. What it does NOT have is a 4-wheel-drive UNlocked high range. That's the additional option the 242 will give you. The unlocked high range is an all-wheel drive that allows you to use 4-wheel-drive on dry pavement. The 231 should not be used in 4WD on dry pavement.

Link to comment
Share on other sites

I swapped in a 242 into my old '88 when I did the 4.0L swap and 4wd conversion.

 

The biggest problem I had was the TC shifter setup. The 242 and the 231 use a different setup and I had a heck of a time figuring out how to make it work. I ended up just using the 242 setup out of an XJ and with a bit of modification it worked.

 

Also remember that the length difference between the 231 and 242 is different. So you may have to address the driveshaft issue. I went from 2wd to 4wd and needed a new one anyways so I just had one made. If your already 4wd you may be able to make it work...

Link to comment
Share on other sites

well if the only difference is that i can drive on pavement with my 4wd engaged well then its not worth the swap.. i thought the 231 case was not locked in when it was in 4wd so i thought it was like a differential.. but if the 231 is locked in when it is in 4wd well then I'm just going to leave it alone

Link to comment
Share on other sites

well if the only difference is that i can drive on pavement with my 4wd engaged well then its not worth the swap.. i thought the 231 case was not locked in when it was in 4wd so i thought it was like a differential.. but if the 231 is locked in when it is in 4wd well then I'm just going to leave it alone

 

Full time is great in the winter when the road is clear for a mile and then its drifted over , clear, the drifted and on and on. You just drive and don't worry about it. It's great in the rain too.

Link to comment
Share on other sites

I have the 242 in my ZJ and love it in bad weather and snow. It helps offset my overly tight limited slip (which is acting solid right now :roll: ) in the snow. Much fun!

 

Stay away from the 249 in early ZJs, it was only AWD and didn't have a lo. Later models had a lockable lo... But stay away from it, the viscous coupling is expensive when it fails.

Link to comment
Share on other sites

It is also marginally weaker than the 231, but in all the outings I've been to with NAXJA I never saw anyone break a 242, so I wouldn't consider it to be a weak sister.

 

 

I've seen 231 parts scattered before... The problem with the 242 is that you can't upgrade the rear output. Which is actually a pretty easy thing to break on a stock 231, and the stock 242 one is the same size.

Link to comment
Share on other sites

I have had both and run my 242 case if fulltime 99% of the time. I prefer the handling of the 242 case it's is great in snow and rain. It also corners better and is great for getting out in traffic on dry pavement too.

 

I might see about swaping a 242HD from a Dodge Durango I just found, it would have the wider chain and some other stronger parts. I'd like to find out what is differend between the Dodge one and the Hummer H1 model.

Hey all, first post :D So what I'm getting here is that there's a "heavy duty" version of the 242 out there, but you can't upgrade the output? Any more info on that would be great. Also, have we decided if a longer/shorter driveshaft is needed?

Link to comment
Share on other sites

The lengths between them is within .5" IIRC.

 

 

The NV242AMG (hummer H1) case is a heavy duty version, but it offers no 2wd provisions. How heavy duty it is, I don't know. It lives behind a 6.5 turbo diesel, and those things are damn slow. Not to mention that we're talking 'heavy duty'as in a truck that uses AMC 20s for diffs. Not that there's anything wrong with the eaton 20, but it's not exacty 1-ton strength.

 

The chevy NV242HD I do not know anything about.

Link to comment
Share on other sites

what is the difference between when it is locked and unlocked in 4wd mode.

 

I still don't understand and i have asked the question before.

 

Locked is the front and rear drive shafts are locked together at the same speed all the time. And the front and rear shafts must always be able to spin at the same speed or you get binding that will break stuff. Off road (dirt) or traction compromised surfaces allow the wheels to slip and maintain the drive shaft harmony.

 

Unlocked means that the front a rear drive shafts are running through a differential just like and open axel (you know one wheel can spin faster that the other) and that allows the them to run at different speeds, this comes into play on dry pavement because the tires grip well on the road and won't slip, so the transfer case has to be able to adjust shaft speeds front and rear. If you do pavement with it locked it will bind up the shafts and transfer case and break stuff

Link to comment
Share on other sites

The lengths between them is within .5" IIRC.

 

 

The NV242AMG (hummer H1) case is a heavy duty version, but it offers no 2wd provisions. How heavy duty it is, I don't know. It lives behind a 6.5 turbo diesel, and those things are damn slow. Not to mention that we're talking 'heavy duty'as in a truck that uses AMC 20s for diffs. Not that there's anything wrong with the eaton 20, but it's not exacty 1-ton strength.

 

You know that AMC20 setup must have proven very strong in development testing? I mean they used it in the Hummer for the military and it seems to have proven itself. So for that application it must have been the right unit for the designed capabilities of the H1.(which are very respectable) That I think gives the AMC20 a hi rating. Yes I am a diehard American Motors guy :)

Link to comment
Share on other sites

I have nothing against the eaton 20. The ones offered in jeeps typically had weak tubes and crappy carriers. All are fixable. But they aren't 1-ton. Eaton made real 1-ton diffs for chevy back in the 60's...

 

 

Personally I think the H1 is a pile. It RTIs about 300. Awesome.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...