Swap in a NV242HD for a NP229?

[Joe Guilbeau]

I might have a good deal on a NV242HD, s0 anyone know how difficult it is to get an adapter plate fabbed up to bolt to the 727 torque-Flite Auto Transmission?

My NP229 is OK, and the Viscous Coupler is fine in it, however that vacuum stuff has been eating at me for some time now, not to mention all that slippage.

I am gathering info on swapping in the NV242HD in place of the NP229, that is currently behind my Chrysler Torque-Flite 727 Transmission.

The NV242 has a 2.72:1 low range and has all of the possible mode ranges including the ability to lock the planetary open center differential if desired.

When the differential is locked so that both the front and rear driveshafts operate in unison (no slippage) it is referred to a "Part-Time" because this mode should not be used on the street, due to lack of tire slippage and therefore binding and torqueing of U-Joints and axle shafts.... therefore the "Part-Time" moniker.

2WD (Sends all power to rear wheels)
4WD High, full-time (Sends power to all wheels)
4WD High, part-time (Locks both front and rear driveshafts for increased traction)
NEUTRAL (Allows vehicle to be towed)
4WD Low, part-time (Doubles the transfer case gear ration for severe road conditions and low-speed pulling power)

I think that these were used in Dodge's (Dakota's and Durango's) and in some Jeeps (WJ's?).

Guess I will have to buy the service manual:
NP229/242 Transfer Case ATSG Technical Rebuild Manual

NV242


NP229

[Crazy_Jeepman]

Looking at the Pic it is going to fit without to much trouble. It APEARS to be clocked correctly. The only problem I see is that the input sticks out more on the NP242 than that of the NP229. Possibly a spacer could be made to correct that. Though it could just the way it looks in the pic, wish I could see the front of it. It does have the round 6 hole NP patern so it will bolt up, and I do think it is clocked corectly. Very possible its a bolt in provided it has the correct spline count on the input shaft. I am not sure what they came behind, but if it is a TF727 or its relatives should be a go!

[ April 12, 2004, 05:00 AM: Message edited by: Crazy_Jeepman ]

[mdill]

From the pictures it looks like both of them
could use the same raw casting for the front
half of the case ! Like has been said only
things to check are lenght and spline count on
input coupler, check to see if the case supports
a mechanical speedo gear, last are the outputs
the same style as the 229 ?? If all that checks
out and you don't mind building linkages it should
be a go.

Mike D.

[Jeep Craze]

difference I see is the 229 is a fixed yoke for the rear shaft and the 242 is a slip yoke, no big deal, just need to get the rear shaft altered.

[TexasJ10]

I think those pictures might be a little deceiving. I think the 231 and 241/242 is a little larger in all dimensions and may be a little tight next to the frame. I think the spline count and indexing is straight bolt on, but I would check the rest of the dimensions. I have a 241HD in storage that I could check this weekend. BTW, the 242 is suppose to be an electrically shifted transfer case. I also have never found a slip yoke eliminator for a 241HD. They have them for the 241, but the output shaft is different on the HD's because of the PTO accomadation.

[ April 12, 2004, 09:03 PM: Message edited by: TexasJ10 ]

[testuser]

A little more info on the fixed yolk.

I've seen plenty of Jeepers break theirs. Typically...most people who do heavy offroading will get a SYE (slip-yolk eliminator) kit which replaces the tailshaft of the xfer case. This can be costly in and of itself. There are two types...a hack n tap and a full replacement. You wouldn't need to get a new driveshaft then.

Here are some topics about 242s over on NAXJA

http://www.naxja.org/forum/search.php?searchid=82218

[DieselSJ]

Keep in mind that the 242 and 242HD are not totally interchangeable, and most parts won't swap between them. A SYE for a 242 will not fit the 242HD.

[zmjeeps]

A couple of answers in one post, I'll try and go in order from top to bottom. 242HD should bolt in place of the 229. Both should be 23 spline. Longer input gear may be a problem, but just put in a shorter one from any other NP tcase, all the 2.72s interchange. Next, there no fixed yoke "kit" for the 242s, you need to replace/cut and thread the mainshaft to do this and no one is doing it. There are fixed yoke kits for the 241 and the 241HD. Actually, they are the same. Only thing that makes the HD different is the case and the low range planetary for the PTO.
If someone knows of a SYE kit for a 242, let me know. The difference between a HD and a standard duty has to do with the differential material, and chain and sprockets. You get one SYE kit, it should work for them all provided outputs are the same. (I used to work for NVG)

[Joe Guilbeau]

Originally posted by zmjeeps:
A couple of answers in one post, I'll try and go in order from top to bottom. 242HD should bolt in place of the 229. Both should be 23 spline. Longer input gear may be a problem, but just put in a shorter one from any other NP tcase, all the 2.72s interchange. Next, there no fixed yoke "kit" for the 242s, you need to replace/cut and thread the mainshaft to do this and no one is doing it. There are fixed yoke kits for the 241 and the 241HD. Actually, they are the same. Only thing that makes the HD different is the case and the low range planetary for the PTO.
If someone knows of a SYE kit for a 242, let me know. The difference between a HD and a standard duty has to do with the differential material, and chain and sprockets. You get one SYE kit, it should work for them all provided outputs are the same. (I used to work for NVG)

Zack...

How the hell are ya!

As you know my dream of the GM conversion for my jeep had to be scrapped...and I was so close to having that dream done!

That stock plan hit the skids and I was near in the RED again!

So, I am gathering from your post that this is might work after all...I can use the input shaft from the NP229, for a standard NP242, and possible canabalize the NP229 pulling the Sun gears and swaping???

I suppose that I need to purchase that NP229/NV242 R&R Manual and read up on it a bit more.

Sorry our deal fell through, finances prevented the culmination...

[zmjeeps]

Joe, not bad, thanks for asking. I do pop my head up from time to time here.
I'm a little fuzzy on the 229 guts, but don't count on using the 229 input gear in the 242. wasn't the 229 2:61:1 low range or is it 2.72:1 low? You can just grap any wrangler/TJ whatever 231 23 spline input gear and you'll be fine. You might be able to play with the chain and sprockets and mix and match. Midest Transmissions can get you some HD parts and so can JB Conversions.

[zmjeeps]

You really want to get a HD 242, get a 242AMG (hummer version). They don't hav the 2wd postion, but I don't use the 2wd pos in the one I have, I use Full Time all the time. No difference in gas milage. You can find them pretty cheap (and new) at military DRMO auctions.

[TexasJ10]

There are fixed yoke kits for the 241 and the 241HD. Actually, they are the same. Only thing that makes the HD different is the case and the low range planetary for the PTO.

When I spoke to JB Conversions they told me their 241 SYE kit would not fit the HD due to output differences. Now you have me curious because I have a 241HD in need of a SYE

[ April 15, 2004, 09:13 PM: Message edited by: TexasJ10 ]

[Joe Guilbeau]

The reason that I am looking at this is specifically for the 2WD operation, as this is my only vehicle (sans 1981 GS1100EX), ie...it is my daily commuter, and with gas and all going up all the time!?!

The NP229 is indeed 2.61:1 and the NV242 has a 2.71:1.

I saw on some thread that the 4-WD Low Part-Time got a 4:1 reduction gearing going on the NV242HD (low range planatary for the Power Take Off??), but am not quite sure that this is correct.

That is pretty good get up and go and a huge leap above the NP229 in terms of no slippage and putting torque to the ground on all 4 wheels at the same time.

Here is some correspondence that should bring back some memories...

Joe,
F.Y.I.,

Ken Koliba
NVG Sales

-----Original Message-----
From: Anguish, Philip
Sent: Friday, March 14, 2003 4:12 PM
To: Koliba, Kenneth
Subject: RE: NP229 Output Shaft Specs (for Randy @ Gear Vendors)

Ken
1. tooth count - 32
2. Diameter of output spline - 1.3917 / 1.4007
3. Output spline length +/- .010 - 2.00
Phil

The above was sent by New Venture Gear personell, you probably know these guys, I was looking at a Gear Vendor overdrive transmission that bolted to the back of the NP229, there was one in a junkyard in Victoria in 2003.

[ACT3]

new reply to an old thread

Hey Guys,
I know this is an old thread, but I thought I'd let you all know this is possible, I just put a NP242 (non HD) in my 1988 Grand Wagoneer (360 and 727). I picked up a NP242 out of an 89 XJ, changed out the input gear to a long 23 spline early gear cut, Tom Woods SYE/driveshaft combo(pricey, but worth it if your going to do it right). And a Novak shifter for positive transfer case shifting. I have enjoyed it immensely, I love knowing that my 4wd will engage every time. If anyone else is interested in such, i'd be happy to talk them through it.

[mikeand217]

Hey,
If you don't mind I could use a little more info on the NP242 conversion. I was driving my 84' G. Wagoneer down the interstate and heard a lovely metallic sound, which of course was my Viscous Coupler disintegrating. So I now have a motionless vehicle. SO any info would be greatly appreciated.