Quest for another 2 speed w/AWD transfer case

[photo_van]

The 242/241 is also 19" long. I'm guessing the bolt pattern on your adapter is the same as the 1/2 ton so you probably wouldn't even have to remove it. If the clocking is the same for between the 241c and the 136. it could be a bolt up !

Do you know the output spline on the 136?

[LiftedAWDAstro]

I looked quick and I think the 136 uses the 5 bolt adapter. Next time the van is on stands I will look better. I don't know the output spline count yet but I do have a Jeep slip yoke for the external splined output available from Darrel if needed. Just have to use a conversion joint.

Do you know the CL to CL of u-joint measurement of the Trailblazer shaft you have? Also what model TB did it come from. I like the idea of going to an aluminum shaft for less rotational mass. Have you had a chance to use AWD and low range yet?

[photo_van]

I think the external spline 242 is 27. I also think the external spline output shaft will have the speedo worm gear cut into the shaft; this will not work re. the VSS reluctor you need to rob from the 241. Something to look at.

I just, I mean in the last week JUST, dumped all my notes re. the driveshaft. I do know it was from a 2001 and that there are two lengths and several different cars; Trailblazer, Bravada, Izsuzu something......

It's snowing now so hope to use the AWD soon. I'll measure the driveshaft when I can get under there but I'm pretty sure it was ~36".

[photo_van]

Finally found some dry ground; the driveshaft measures 36 inches exactly (well as best I can tell with a tape measure) center to center. The slip yoke is 32 spline.

[LiftedAWDAstro]

OK, quick post for now...

I mated a front half of a NP241C and the back half of a NP242J and the only mod was making the shift sector so it no longer has the detents for each position! I used all the internals of the 242 except for the input shaft and 6 pinion planetary from the 241. They are interchangeable between the 2 though.

The other option is to mount the adapter offset the 90 degrees and build a new crossmember mount. Not even sure this would be a correct way to go as the weight would be taken from the side rather than resting straight down.

Pics to come later!

Transfer case chains

[LiftedAWDAstro]

NP241C



NP242J



Here is where the only real difference in the case design lies. This is where the shift sector goes.

241



242



Found several parts are direct interchanges: The input bearing and seal housing is identical as well as the oil pump and pickup tube. You can swap the front outputs between the cases although in this instance the chains are different widths.

[LiftedAWDAstro]

Found the main shafts will interchange as well. They are not a direct swap but if you were placing the 241 guts into a 242 case and front input planetary, it will work fine. And vice versa for the 242 guts into the 241 case.

241 guts:





242 guts:





241 has a 6 pinion planetary:



Where the 242 only has a 3 pinion planetary:

[LiftedAWDAstro]

To fit the 242 guts into the 241 front case half, I needed to make the shift sector smaller. This required removing the detents.

Stock 242 sector inside:



stock 241 sector inside:




242 left, 241 right. The notches (detents) on the left side of the 242 sector were ground off for clearance inside the 241 case half.



After:

[LiftedAWDAstro]

Now here is a question for you guys. Can the t-case adapter be mounted about 70 - 80 degrees from horizontal as long as a beefy mount was made to bolt it to the stock rubber mount?

241 with adapter:



242 with adapter: Note: this is the only way the GM adapter will mount to the Jeep t-case and get all 6 bolts lined up.

[MountainManJoe]

Great pics. Keep 'em coming.

[LiftedAWDAstro]

Based on this pic here,



I will need a 75 degree up clocking ring. I will be making some calls to see if something like this will work.

[photo_van]

Great info Dean. So the main shafts are the same! (other than the spedo drive). That's great news. Also the 6 gear planetary is a nice upgrade, many of the Jeep guys run those in their 231's and I was wishing I had one for my 242.

Looks like the clocking ring is a must, $50 on ebay!

Looking good!

[LiftedAWDAstro]

I found a guy locally who has a 2002 242WJ but it was behind a 4.0L so I am guessing it has the 27 spline exposed output. My real problem now is that I don't have any extra cash. Gotta pay the IRS a bunch this year and Lynne got her layoff notice that is effective at the end of the school year! This project is going to be on hold for a while now. May even need to resort to selling the van...we'll see.

[photo_van]

Sorry to hear that, hope it all works out OK.

[LiftedAWDAstro]

It will. It always does. Just a little stressful for the next little while...thankfully I make my own hard apple cider!