Well I went to a junkyard awhile back and stumbled upon a 1999 Durango with the NP242 in it. Upon seeing that, I had to get it. It was fascinating to me that this was the case with 4WD FT. I couldnt help but think how neat would it be for my truck to have that, plus 4Hi lock and 4Lo Lock. After a couple of hours of tearing it apart and swapping input gears from my 241. I'm happy to say that my truck might be the only one with a 242 behind a Cummins.

 

How bout a full write up? Everything work? You engage the CAD?

 

Hey ham bone, almost everything works great, except the CAD, I'm still playing with the vaccuum switch to gwt it engage in full time. I don't know if my pictures showed up in the last post, but I do have a teardown and comparison of both.

 

Nope. No pics in the first post.

 

Woah, ok I hope these aren't too big for the post lol

Ok, so like I said, I found the case on a 1999 Durango that had a 5.9 in it. Seemed odd to me because it didn't have any R/T insignia on the side. Also, one thing to consider when doing this swap....being able to use your speedometer. The picture below shows the VSS, the one above is missing this. A slight issue, but I've found a way to use the ABS sensor input.

 

First and foremost, it always a safer bet to swap the input gears so as to eliminate any issues down the road when it comes to installing. The top pic (241) has a longer snout on the input, while the bottom pic (242) has a shorter snout. I'm not all that familiar with why the gears are different sizes, considering one came off a 46re and the other a 47rh.

To get to either input gear, you're going to need a 15MM to unbolt the two halves and the two piece tailhousing on the 242. The 241 will require the same, except on the tailhousing, those require a 14MM. Oh and make sure you have a set of lock ring pliers on hand. LOCK RING, NOT SNAP RING. I cannot stress that enough as both cases, if not all of them have a retaining ring inside the tailhousing.

 

Once the two cases are apart, you'll need to remove the chain and its sprockets in an effort to pull the mainshaft out. The 242 has lock rings holding those sprockets in, the 241 only has one on the front output.

 

After removing the lock ring on the sprockets for each case, I removed the main shafts as well. What takes 30 seconds on the 241, took me an hour for the 242 due to the tight fitting and lack of play. Once that's out, we move on to the front of the case where the input gear is.



The cover that goes here has four 10MM bolts. Inside that cover is another lock ring that holds the input gear and planetary assembly. Remove that and it will fall out.



242 on the left with 3 planets and 241 on the right with 6 planets.

 

After tearing it all down and swapping the planet assemblies from one case into the other, you then do the reverse of everything to put it back together. When finished, slide it underneath the truck and stab it back in.

 

So the six pinion planet fits in the 242 case just fine? I was considering this swap (for full-time four wheel drive....) but, didn't want to sacrifice the strength of the 241 t-case.