ZJ
NV242
Transfer Case Swap
Ok fellas...
Here it
goes...I did it...It works...All is well!
First
thing you need
to do for this swap is go to a bone yard and find
a donor. Either an XJ or ZJ NV242 will do. 242's were available in 80's
model XJ's and all models of ZJ's (as an option) so look in them all.
Keep in mind that ‘93 ZJ's did come with this as an option so keep
looking in them if you see one in the yard. But they are very common on
XJ's. I found around 20 XJ's and 6 of them had this case. All you have
to do is look at the shifter. It should have - 2WD - 4 Part time - 4
Full time - N - 4 Lo.
There you have
it...
TOOLS NEEDED
- Good set
of snap rings pliers and I mean a really good set. Spend some
money - they are very important!
- A socket
set and screwdriver set
- Hammer
- Wrenches
don't hurt
- (OK you
need some basic tools and the snap ring pliers...GOOD ONES!!)
- You will
also need RTV and Tranny fluid
You
don’t have to be
a mechanic to do this job. It’s really not that
hard. I think it took me about 14 hours total (over 2 days - half a day
one day and the whole day the second). But I did a lot of reverse
engineering you will not need to do.
Let's get
started!
Here is my
donor. It came out of an '89 XJ with 65,000 miles on it.
I cleaned it up
and
made sure it went
smoothly into all the gears.
NICE....
Then I pulled
the 249 - don't worry, it's not really that hard.
Drop your front
shaft.
This is a very
important part... Chock your
wheels... Chock your wheels... Chock your wheels...
Are everyone's
wheels chocked???? Good, let's continue.
Drop your skid
if you have one. It's only three bolts. Not that hard,
is it?
Then remove the
rear shaft
Put
a jack under the
tranny (right behind
the pan). Remember to leave yourself room to remove the cross member.
Now remove the cross member. There are two bolts on each side and one
big one in the middle in the tranny mount. I didn’t take pictures of
this because I thought you could figure it out....
Remove the transfer
case. I didn’t get any pictures of this step
because its a pain to take pics while on your back under a truck, but
there are 6 bolts - 15mm If I remember correctly.
If you can’t
find them, skip this step and drink a beer. You cannot do
this mod!
Then you drain
the T-case. I did this cool design on my driveway...
Here is the old
249 on the ground
At this point, I
drank some beer because that was it for the day.
Before you ask, it
did
not take all day. I
didn’t get started till almost 5 pm and got the transfer case out in
about 1 1/2 hours. (Conservative - it probably wasn’t that long, but I
had trouble with one of the bolts. Hint: ON top...)
Another
hint: Use
deep well socket. The studs stick out too far for a
shallow well socket and you could waste a lot of time trying to use
one. Don't
ask me how I know.
Okay, so this is
the part you need.
There
is a cover over
it. You can’t miss it. Then there are a few snap
rings under that cover. You will have to remove this plate. Its on the
tail shaft…again you will see it.
Remove
the speed-O
sensor that is right
next to this. (Just pull it out and put it on the side out of the way.)
Now back to your
hole...
Inside there is
a snap ring. Here is where the good pair of snap ring
pliers come in. Loosen all the screws on the cover and break it loose.
Use a hammer and screwdriver as it’s RTV'd. Grab the snap ring and
slide it off as you slide the cover off. Once that is out of
the way, take out the bolts in the center of the
case and break it open.
You will see
this inside.
On
the left side
behind the shifter that
you see slid down, is the sun gear you need. You will need to tap the
input slightly to get it out.
Here is what it
looks like out of the case.
You
don’t have to
remove it from the
planetary gears. You can use the whole set, but I decided to pull mine
out and look at them. See me with the snap ring pliers. (GOOD ONES!)
So now that you
have completely taken the 249 apart, it will be a
breeze to take the 242 down.
Make
sure you do it
on a clean surface! When you get the 242
apart (pretty much the same) make sure you pay
close attention to how you are doing it. You will notice the innards of
the 242 aren't much different.
There is a huge
shift mechanism with 2 shift forks.
To
remove these
shift
forks, start by
moving the shift linkage to the top. I'm not sure which way you have to
turn it, but you will see. There is a pin on the shift fork that hooks
to the swing linkage on the inside of the case. I used a pry bar and
wedged it in between them. Use just enough pressure to pop the shift
fork pin out and slide it up. When this is done, shift the T-case again
and the lower shift fork will pop out and the sun gear will come out at
the same time. Don’t forget to take the front cover off and remove the
snap ring first.
Install the sun gear
out of your 249 It will take some tapping - I used
the hammer handle. Make sure its fully seated.
Okay,
I guess I left
out a part on both of the break downs - the chain.
It removes by sliding one of the gears up the shaft and off it will
come. It goes on pretty easily.
Here's the 249
input on the 242.
On reassembly use
RTV.
I went a little
overboard, but here it is bolted back together. (I did cut the excess
RTV off with a razor when it dried.)
In this picture you
can see the short shift linkage from the 242 lying
on the floor and the 249 linkage on the transfer case.
DON'T DO THIS,
IT WON'T WORK!!!
So I put the 242
shifter linkage back on.
Install
your new
T-case and put the selector in 2WD and switch the
T-case into 2 wheel drive. Adjust the slide nut on your linkage so that
you can hook the linkage up. That should work for the full throw. I had
a buddy shift back and forth until I had it adjusted correctly.
If the donor T-Case
is from a '93 or newer, you can just plug the shift
indicator in. If it’s not, then you will need to buy the part from Jeep
(as soon as I do I will post the part number) The speedometer sensor is
another concern in a pre '93 T-case. Your sensor out of your 249 will
work and obviously will plug in.
On the inside of the
truck remove the radio bezel (6 philips screws)
and pop it out. There are 3 philips screws in the Vehicle Info center.
Pull it out and you will see two sets of plugs, a red one and a black
one. I think the red ones where hooked up but I’m not sure. But the
point is, whichever ones are hooked up, unhook them and hook up the
others.
That's it! Make
sure everything is tightened up and fill your transfer case
with fluid.
Then try
it out…
Mine did this…
If you have any
questions, be sure to ask!
