Jeep NV242 transfer case breakdown

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Requirements
  • Wheel Chocks / Blocks
  • 5/16" Socket w 1/4" Ratchet
  • 1/2" Socket w 1/4" Ratchet
  • 15mm Socket w 3/8" Ratchet
  • 10mm 12-Point Socket w 3/8" Ratchet
  • Ratchet Extensions
  • 10mm Hex Key
  • Flat Head Screwdriver (Small & Large)
  • Rubber Mallet
  • Needle Nose & Regular Pliers
  • Heavy Duty Retaining-Ring/Snap-Ring Pliers
  • Heavy Duty Lock-Ring Pliers
  • Gasket Scraper
  • RTV Gasket Sealer (Ultra Black, Gray, Red, or Ultra Copper)
  • 2 Pints ATF+3 or ATF+4 (Check your service manual!)
  • Bottle Pump or Spout
  • Oil Catch Pan
  • Rags
  • Jack Stands (Recommended)
  • Floor Jack (Recommended)

The following describes a simple breakdown of the NV242 transfer case while it's still installed in a Jeep. The following was performed to quickly eliminate a bad leak. Therefore having to drop the whole case was unnecessary. This experience can prove beneficial when doing further upgrades such as the Slip Yoke Eliminator kit. For now though, we're just gonna fix a leak.

This article consists of the following parts:

  1. Listing of the tools needed and what they will be used for and the breakdown of the case.
  2. Clean up & reassembly of the case.
  3. Technical view of the 242 t-case and the differences between them. Somewhere between late 1990's and early 2000's, New Process changed it's name to New Venture. Therefore you will find that there is an NP242 and the NV242. My 242 has the New Process tag but it's designed like the NV242.

Please, please, please read this write-up before you tear into your case. Even though this is the NV242 out of my '98 ZJ, the basics of this breakdown applies to almost any t-case. Of course there will be differences.

Let me explain to you about the types of pliers used here. When I say Heavy Duty, I mean don't go cheap on these. The pics below have an insert that will show you the type of rings that the pliers will be used for. The pliers on the Left are Internal & Extermanl Retaining-Ring/Snap-Ring Pliers. The pliers on the right are Lock-Ring Pliers.

Jeep NV242 transfer case breakdown 31.jpg Jeep NV242 transfer case breakdown 32.jpg

The next task to be done will be choking/blocking all four wheels. Even if the trans on your Jeep is in park, once you start messing with the t-case, your Jeep could become effected and roll away while you are underneath. I placed my Jeep in park but kept the t-case in neutral so I could rotate the rear driveshaft as I was taking it off. Keeping the t-case in neutral also helped out a bit when it came time to remove the lock-rings.

On the tools list I mentioned jack stands. This is for those who have small or no lift at all. My overall suggestion is this, if you have no problems getting underneath your Jeep then stands may not be necessary. Keep in mind that for this task we are not dropping the t-case but you will still need plenty of room to move around underneath.

Breakdown

Once you are certain that your Jeep will not roll away it's time to crawl underneath and drain your t-case of fluid. You will see 2 plugs, unscrew the drain plug with a 10mm Hex Key.

Jeep NV242 transfer case breakdown 51.jpg

Next use either needle nose or regular pliers and remove one of the two metal bands securing the Slip Yoke rubber boot, which is located on the slipyoke portion of the driveshaft. The strap to be removed secures the boot to the transfer case slinger.

Jeep NV242 transfer case breakdown 52.jpg

Jeep NV242 transfer case breakdown 45.jpg

You will find that this strap is a pain in the ass to remove. If you feel that it can not be reused, fear not as zip ties will make an easy replacement. If you use zip ties, you must be careful in removing them so that you do not damage the boot next time you do this project.

Jeep NV242 transfer case breakdown 46.jpg

Move to the rear of the axle and remove 4 bolts and 2 yoke straps that secure the drive shaft to the rear axle using a 5/16" socket or wrench. This is where having the t-case in neutral helps. Once you have the 1st yoke strap removed you can grab the driveshaft and rotate untill you remove the 2nd strap. Be prepared to catch the ass-end of the driveshaft in case it drops to the ground. If it does not drop, don't worry as you are about to learn why the other end is called a Slip Yoke.

Jeep NV242 transfer case breakdown 48.jpg

Jeep NV242 transfer case breakdown 49.jpg

Jeep NV242 transfer case breakdown 50.jpg

Simply grab the driveshaft and slide it forward as if you were trying to shove it into the transmission. The ass-end should disengage itself from the axle. You will notice that the driveshaft is rather light. Now slide the shaft out of the transfer case and place it out the way. What you should see is this.

Jeep NV242 transfer case breakdown 43.jpg

Unplug the speedometer wiring harness connected to your transfer case tail housing. Here you will need to use a small screw driver to slide out the red key locking the connector in place. Disconnect the plug from the speedometer gear.

Jeep NV242 transfer case breakdown 53.jpg

Using a 1/2" socket, remove the retaining bolt and metal clip securing your speedometer gear housing to the tail housing.

Jeep NV242 transfer case breakdown 44.jpg

Jeep NV242 transfer case breakdown 42.jpg

Firmly grab the speedometer gear housing and carefully pull it out. If you have bigger tires already, now would actually be a good time to change this gear out to correct your speedometer. Remember the original orientation of the speedo gear during reassembly!

Jeep NV242 transfer case breakdown 40.jpg

Here is where the fun really begins. The removal of the slinger was an ass kicker for me. There are several ways to remove this. You can use a gear puller with a 5" reach to extract. This can be rented from your local autoshop.

Jeep NV242 transfer case breakdown 56.jpg

Or use a chisel / flathead screwdriver & hammer. I ended up making a slight groove for the flathead to grab onto and hammered the slinger loose. It rotated counter clockwise off.

Jeep NV242 transfer case breakdown 37.jpg

Jeep NV242 transfer case breakdown.jpg

Jeep NV242 transfer case breakdown 05.jpg

Now that you have that P.O.S. off, there will be a metal slip-ring (if you have one). Simply slide it off and you should see your 1st lock-ring and the Output Shaft Seal.

Jeep NV242 transfer case breakdown 01.jpg

Grab your lock-ring pliers and go after the lock-ring holding the Output Shaft Seal. If you plan on re-using the lock-ring, be careful not to damage it. It is possible to bend & warp the ring.

Jeep NV242 transfer case breakdown 34.jpg

Remove the Output Shaft Seal by tapping a flathead screwdriver with a hammer all the way around the seal until it comes off.

Jeep NV242 transfer case breakdown 54.jpg

Jeep NV242 transfer case breakdown 36.jpg

Remove the 2nd lock-ring that keeps the Output Shaft Bearing in place.

Jeep NV242 transfer case breakdown 33.jpg

Remove the snap-ring that holds the tail Housing in place.

Jeep NV242 transfer case breakdown 29.jpg

Jeep NV242 transfer case breakdown 26.jpg

Jeep NV242 transfer case breakdown 28.jpg

Remove all bolts holding the transfer case tail housing using a 15mm socket.

Jeep NV242 transfer case breakdown 27.jpg

After all bolts are loose, you should be able to whack the tail housing with a rubber mallet. If you end up having to use a screwdriver & a hammer be careful not to damage the case as it is made of aluminum.

Jeep NV242 transfer case breakdown 55.jpg

Grab the tail housing and slide it off the Output Shaft.

Jeep NV242 transfer case breakdown 23.jpg

Here is where you should be. What you are looking at is the oil pump.

Jeep NV242 transfer case breakdown 21.jpg

Look carefully at the teeth deep inside the output shaft and the teeth on the speed gear and see how they meet to measure the speed of the Jeep.

Jeep NV242 transfer case breakdown 25.jpg

Now it's time to break open the t-case. Using a 15mm socket you will remove all bolts except for one at the top. For the top bolt you need a 10mm 12-point socket. Pay attention to where each bolt came off and arrange them accordingly on the ground. You will notice that a couple of them are longer and that 2 of the bolts have washers. All bolts will need to go back to the specific hole they originally came from.

Jeep NV242 transfer case breakdown 57.jpg

Here is a look at the bolts. Notice the 12-point bolt on the right. The other two bolts are the same except that one has a washer & is slightly longer.

Jeep NV242 transfer case breakdown 15.jpg

The 12-point bolt gave me one hell of a hard time. I ended up having to reach around the back end of the transfer case only to realize that I had forgotten there is a nut back there that is used to hold a wire retainer. Not only did I have to unthread the 12-point bolt from the t-case itself but also from this nut thus making life rather hard. This nut is not required for reassembly. Just make sure you keep the wires out of way.

Jeep NV242 transfer case breakdown 13.jpg

Here is the order in which the bolts are placed. Notice the two bolts on the far left & right with washers & the 12-point bolt.

Jeep NV242 transfer case breakdown 16.jpg

Look at the seam of the t-case and you find a small notch where a flat head screwdriver can be placed. Carefully pry open the t-case without using excessive force which can cause damage. Watch out as more fluid will pour out.

Jeep NV242 transfer case breakdown 58.jpg

With the transfer case partially separated, you should be able to remove the oil pump by lifting up and pulling it off the output shaft. There is a small oil pickup tube at the base of the pump that will need to be disconnected. It's just held in by a rubber O-ring and will unplug with little effort.

Jeep NV242 transfer case breakdown 60.jpg

Remove the t-case half and set it aside. At the base of the t-case, you will find a flat round magnet in a slot where the two halves come together.

Jeep NV242 transfer case breakdown 10.jpg

This is a collecting magnet used to grab metal shavings. It will look rather fuzzy at first but truth be told, that's metal shavings. Pull this magnet out and clean off all metal fillings attached to it. Look for larger chunks that would indicate serious wear or damage to the components inside the case. In the photo below you will see the shavings left behind after a slight cleaning. I used lots of brake cleaner & rags.

Jeep NV242 transfer case breakdown 12.jpg

At this point, the break down is complete.

Jeep NV242 transfer case breakdown 06.jpg

Assembly

A gasket scraper & brake cleaner, or degreaser of your choice will help out a lot. Once again be careful not to damage the case itself. Be sure not to allow any of the old gasket residue to fall inside the case.

Jeep NV242 transfer case breakdown 09.jpg

Clean up the tail housing as well.

Jeep NV242 transfer case breakdown 08.jpg

Jeep NV242 transfer case breakdown 04.jpg

It may not be possible to get it all 100% clean but make enough of an effort to ensure that the new sealant will stick.

Jeep NV242 transfer case breakdown 07.jpg

Once you have everything cleaned off, it is time to get out some RTV Gasket maker and have at it.

Jeep NV242 transfer case breakdown 14.jpg

Using a 1/16" to 1/4" bead of RTV, make a continuous even bead of silicone to one surface surrounding all bolt holes.

Jeep NV242 transfer case breakdown 17.jpg

Let the silicone dry for a bit then assemble the 2 halves. Finger tighten all bolts (or lightly use your socket) until the silicone begins to squeeze out a bit all around. Allow the silicone to dry for 1 hour then retighten 1/4 to 1/2 turn.

Jeep NV242 transfer case breakdown 18.jpg

Insert the oil pump. This is a bit of a tricky install because the oil pickup tube MUST be inserted into the oil pump.

Jeep NV242 transfer case breakdown 60.jpg

Jeep NV242 transfer case breakdown 20.jpg

Just use a small flathead screwdriver to do this.

Jeep NV242 transfer case breakdown 59.jpg

Jeep NV242 transfer case breakdown 19.jpg

Here is a bit of backwards orientation. This photo will give you an idea what you are trying to accomplish.

Jeep NV242 transfer case breakdown 11.jpg

Using a 1/16" to 1/4" bead of RTV, make a continuous even bead of silicone to one surface surrounding all bolt holes for the tail housing.

Jeep NV242 transfer case breakdown 22.jpg

Once again allow the silicone to dry for a bit then carefully slide the tail housing over the output shaft. Finger tighten all bolts (or lightly use your socket) until the silicone begins to squeeze out a bit all around. Allow the silicone to dry for 1 hour then retighten 1/4 to 1/2 turn.

Jeep NV242 transfer case breakdown 24.jpg

Once the RTV has dried, tighten every bolt down and insert the snap-ring onto the tail housing.

Jeep NV242 transfer case breakdown 29.jpg

Jeep NV242 transfer case breakdown 26.jpg

Insert one of the 2 lock-rings onto the output shaft. Pay close attention this part. The lock-ring will slide into a groove on the output shaft right up to the output shaft bearing. Make sure it snaps in the groove.

Jeep NV242 transfer case breakdown 30.jpg

Insert the output shaft seal. This might be a bit tricky though, if you look at the backside if this seal you will see a thin round retaining spring. This spring will make inserting the seal a bit of a pain in the ass.

Jeep NV242 transfer case breakdown 36.jpg

The rubber mallet will come in handy for this task.

Jeep NV242 transfer case breakdown 35.jpg

Insert the last lock-ring. This lock ring will also slide into a groove on the output shaft right up against the output shaft seal. Becareful not to damage the seal!

Jeep NV242 transfer case breakdown 34.jpg

If you have a slip-ring, insert it on top of the lock ring.

Jeep NV242 transfer case breakdown 38.jpg

Insert the slinger.

Jeep NV242 transfer case breakdown 41.jpg

Re-assemble the speed gear. Remeber the original orientation of the speedo gear during reassembly!

Jeep NV242 transfer case breakdown 40.jpg

Jeep NV242 transfer case breakdown 39.jpg

Jeep NV242 transfer case breakdown 44.jpg

Now you should be at this point. Granted there is a ton of RTV that can be seen. I'm not out to win any showroom trophies but if having some extra silicone bothers you, then by all means trim it off.

Jeep NV242 transfer case breakdown 43.jpg

Check your service manual and fill the t-case up with AT+3 or AT+4 of your choice and watch for leaks. If there are none, then resume the assembly by putting your driveshaft back on to the t-case in the reverse order that you took it off.

Jeep NV242 transfer case breakdown 47.jpg

Please keep in mind that is only a basic break down & re-assembly of the 242 that came with my ZJ. Its a 98 with well over 134,000 miles at this time of this write-up. I know there are many other versions of the 242 as mentioned earlier. Hopefully with this knowledge, you will be able to do this and eventually move on to bigger projects like installing a Slip Yoke Eliminator kit.

Disassembly & reassembly of many transfer cases are the same however. You may find that the bolt on your case may have 10mm all the way around rather than 15mm like mine. Just pay close attention to what you are doing at all times. Make notes of where everything goes, take your time and all will go smoothly.

Technical info

An earlier version of the 242, the NP242 (New Process) has a 3 bolt extension housing that attaches to the tail housing / rear retainer similar to the NP231. Plus you have a 249-242 hybrid t-case.

This is the NP242 that has the 3 bolt extension housing (#14) that bolts up to the tail housing / rear bearing retainer (#13). This model is offered on 93 to 95 ZJ's.

Jeep NV242 transfer case breakdown 62.jpg

Jeep NV242 transfer case breakdown 03.jpg

  1. Shift Lever.
  2. Sector O Ring
  3. Shift Lever Retaining Ring
  4. Outer Shift/Mode Fork Pads
  5. Center Shift Fork Pad
  6. Center Mode Fork Pad
  7. Range Shift Fork
  8. Mode Shift Fork
  9. Front Retainer Seal
  10. Front Bearing Retainer
  11. Input Gear Bearing
  12. Input Pilot Bearing (input gear / mainshaft)
  13. Rear Bearing Retainer (a.k.a. Tail Housing)
  14. Extension Housing
  15. Bushing
  16. Output Shaft Seal
  17. Magnet
  18. Indicator / Vacuum Switch Seal (speedo gear)
  19. Front Yoke Nut
  20. Front Yoke Seal
  21. Front Yoke (also pictured are the slinger & oil seal)
  22. Front Output Shaft Rear Bearing (with lockring)
  23. Drive Chain
  24. Mainshaft Bearing Rollers
  25. Differential Sprocket (pictured is the whole differential assembly)
  26. Input Gear
  27. Oil Pump Tube O-Ring
  28. Oil Pump Pickup Tube Screen
  29. Low Range Gear
  30. Shift Sleeve
  31. Oil Pump Seal
  32. Rear Bearing (with snap ring)
  33. Oil Pump
  34. Rear Case Half
  35. Mainshaft


The photo below is the NV242 (New Venture) that I currently have under my '98 ZJ. This is the newer 242 that is bolted on 96 to 98 ZJ's and is also featured on WJ's & KJ's.

However, there are models like this that will have the New Process tag! Just look for the tail housing / rear bearing retainer (#11), slinger (#31), and the slip yoke boot (#37).

Jeep NV242 transfer case breakdown 61.jpg

Jeep NV242 transfer case breakdown 02.jpg

  1. Front case
  2. Bolt
  3. Drain / Fill Plugs
  4. Nut
  5. Detent Pin
  6. Seal
  7. Seal Plug
  8. Detent Pin Spring
  9. Detent Plug
  10. Bolt
  11. Rear Bearing Retainder (a.k.a. Tail Housing)
  12. Goo in a Tube?
  13. Magnet
  14. Vent Tube Assembly
  15. Spacer (there are 2 for this half of the case)
  16. Washer (there are 2 for this half of the case)
  17. Bolt (used for the spacer & washer listed above)
  18. Retainer (used with the 12-point head bolt that holds wiring out of the way)
  19. Indicator / Vacuum Switch (speedo gear assembly)
  20. Indicator / Vacuum Switch Seal
  21. Vent Tube Assembly
  22. Vent Tube Assembly
  23. Vent Tube Assembly
  24. Rear Case
  25. Oil Pump Tube O-Ring
  26. Oil Pickup Tube
  27. Oil Tube Pickup Connector
  28. Transfer Case Oil Filter (screen)
  29. 12-Point Head Bolt
  30. Lock-Ring
  31. Transfer Case Flange Slinger (also pictured is a slip-ring if equipt)
  32. Output Shaft Bearing
  33. Reatining Ring (snap-ring)
  34. Output Shaft Seal
  35. Slip Yoke Boot Front Clamp
  36. Slip Yoke Boot Rear Clamp
  37. Slip Yoke Boot


The majority of the photos used here are by zj-monster with the exception of a few. Those photos are courtesy of Eddie at 4x4xplor.com and came in handy when a few weren't taken during the process.