Replace YJ Transfer Case NP231J - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Replace YJ Transfer Case NP231J

Smittybilt Hard Tops @ Oconee Off-Road! 706-534-9955XHD Heavy-Duty Hood Latches for JK and TJ available at OcoFS: Jeep Fog Light LED Bulbs! Several Brightness Options!

Reply
Unread 07-17-2007, 07:07 PM   #1
jeephobbie57
Registered User
 
Join Date: Jul 2007
Location: New Jersey
Posts: 14
Replace YJ Transfer Case NP231J

Anyone ever changed out the transfer case, Nothing fancy, stock case no lift is cracked going to change it out with a used case . Any step by step helpful tips or suggestions out there?

jeephobbie57

jeephobbie57 is offline   Reply With Quote
Unread 07-17-2007, 07:31 PM   #2
lah2420
Registered User
1995 YJ Wrangler 
 
Join Date: Mar 2006
Location: , Arkansas
Posts: 853
It's not too bad. Put a stand under it, take the skid down, then put a floor jack under the tranny. You'll unhook the linkage--one connection--, take 6 nuts loose, pull the vacuum connector off of the top, pull the speedo cable, remove driveshafts, pull the vent hose and tug it off to the rear. It will weigh about 75 lbs if I remember right, so be ready for that. You might have to use the jack under the tranny to lower it a little for the top nuts. And before I forget again, drain the tcase first. The fluid doesn't taste very good.
lah2420 is offline   Reply With Quote
Unread 07-17-2007, 07:43 PM   #3
northjeep
Jeep parking ONLY
 
northjeep's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2006
Location: Auburn, NY
Posts: 1,491
Removing and replacing is very easy.
Drain first.

Mark the drive shaft to output yoke positions with a paint pen.

Set the unit to neutral or 4lo to make installation easy (I like neutral).



Now is a good time to make sure the new t-case is in fully functional condition. Make repairs b4 you have it installed and you will be laughing down the road.
__________________
-NorthJeep - >> Just Enough Essential Parts
RED Jeep Club member - YJ Club - 258's Unite
northjeep is offline   Reply With Quote
Unread 07-17-2007, 08:11 PM   #4
rustywrangler
Got my eye on you.....
 
rustywrangler's Avatar
 
Join Date: Apr 2005
Location: Syracuse, NY
Posts: 18,616
The only thing I would do differently than stated above is support the tranny first, not after the skid is dropped. If the tcase is already cracked, I would not support it all with that.
__________________

Congenital Heart Disease is a reality for me, BOTH of my children have it. Please read up and become aware for future generations

Lydia Ann-Acquired 08/05/05 Open Heart surgery 08/10/05
Jacob Patrick-Acquired 01/17/08 Open Heart surgery 02/15/08
rustywrangler is offline   Reply With Quote
Unread 07-17-2007, 08:17 PM   #5
learfxr
Registered User
2000 TJ Wrangler 
 
Join Date: Nov 2006
Location: Springtown, Texas
Posts: 682
Use caution dropping the skid if you're using a little floor jack. Had mine shoot out as I finished the last bolt and got smacked in the face with a skid plate with a big transmission pushing down on it. I treat it with much more respect now.
__________________
89 YJ TBI350 TH350 203/300 Rocks and 43's in work

00 TJ 8.8 swap, 35's and 4.88's
learfxr is offline   Reply With Quote
Unread 07-17-2007, 08:21 PM   #6
rustywrangler
Got my eye on you.....
 
rustywrangler's Avatar
 
Join Date: Apr 2005
Location: Syracuse, NY
Posts: 18,616
Quote:
Originally Posted by learfxr
Use caution dropping the skid if you're using a little floor jack. Had mine shoot out as I finished the last bolt and got smacked in the face with a skid plate with a big transmission pushing down on it. I treat it with much more respect now.
OWWWWWWWWWWWW, Yea, SUV jack comes to mind.
__________________

Congenital Heart Disease is a reality for me, BOTH of my children have it. Please read up and become aware for future generations

Lydia Ann-Acquired 08/05/05 Open Heart surgery 08/10/05
Jacob Patrick-Acquired 01/17/08 Open Heart surgery 02/15/08
rustywrangler is offline   Reply With Quote
Unread 07-17-2007, 08:25 PM   #7
lah2420
Registered User
1995 YJ Wrangler 
 
Join Date: Mar 2006
Location: , Arkansas
Posts: 853
Good point Rusty. My brain tranny must have been in neutral there.

As far as the skid, I removed the tranny bolts, loosened all the skid bolts, and then took one side down at a time with the floor jack. Much easier to control that way.
lah2420 is offline   Reply With Quote
Unread 07-17-2007, 08:55 PM   #8
learfxr
Registered User
2000 TJ Wrangler 
 
Join Date: Nov 2006
Location: Springtown, Texas
Posts: 682
Sucks to have shop accidents and you're the only person around. Had to reach for the floor jack and lift the skid back off of me. Hit me at the side of one eye and gave me a good lump and bent my glasses. I had the skid off a hundred times trying to mount the 727 transmission. It sucked
__________________
89 YJ TBI350 TH350 203/300 Rocks and 43's in work

00 TJ 8.8 swap, 35's and 4.88's
learfxr is offline   Reply With Quote
Unread 07-18-2007, 08:10 AM   #9
Tim Berry
Registered User
1991 YJ Wrangler 
 
Join Date: Sep 2006
Location: Kansas City Area
Posts: 167
You may need to drain the trans too - I don't see which one you have but the ax-15 uses the t-case input to seal the rear of the transmission case.
__________________
Two lifted jeeps and a Radio Shack Microphone.
Tim Berry is offline   Reply With Quote
Unread 07-21-2007, 09:43 AM   #10
jeephobbie57
Registered User
 
Join Date: Jul 2007
Location: New Jersey
Posts: 14
T - Case Change OUt

Thanks for all the feed Back. A ;lot of good tips , I wasn't aware there a vent , I saw a metal tube I thought that was the vacuum line. Where is the vent tube?

Also different question Should I lube " grease the spline before I join the tranny and T- Case If so ... What type of lube or grease ?

Is it a good Idea to put the jeep front end up on ramps or jack stands ? The jeep is not lifted ... and it just has 31 X 10.5 tires with 15 in wheels Basically a stock 91 YJ jeep with some new or used parts as needed ... a 4.0 Motor AX15 tranny
overall the jeep is in desent shape . frame is not rusted out ... with 188K miles

How long to do the job ? What do you guys think ? a good mechanic 4 hours and me maybe 8 hours ... I know it's hard to answer that question ..


Thanks the jeephobbie57 guy !
jeephobbie57 is offline   Reply With Quote
Unread 07-21-2007, 10:52 AM   #11
ncjeepinyj
Registered User
 
Join Date: Aug 2004
Location: Mooresville NC
Posts: 1,075
Quote:
Originally Posted by lah2420
It's not too bad. Put a stand under it, take the skid down, then put a floor jack under the tranny. You'll unhook the linkage--one connection--, take 6 nuts loose, pull the vacuum connector off of the top, pull the speedo cable, remove driveshafts, pull the vent hose and tug it off to the rear. It will weigh about 75 lbs if I remember right, so be ready for that. You might have to use the jack under the tranny to lower it a little for the top nuts. And before I forget again, drain the tcase first. The fluid doesn't taste very good.

Only thing i can think of to add to this is that you might atleast need to take the t-case shifter knob off so wont get hung up on the way down.
__________________
95 YJ, SOA, 35's, 4.88's, 8.8
ncjeepinyj is offline   Reply With Quote
Unread 07-21-2007, 05:01 PM   #12
King03Kev
Registered User
1987 YJ Wrangler 
 
Join Date: Oct 2005
Location: NJ
Posts: 615
Like mentioned above, support trans/motor after jacking weight off of skid plate. Remove skid, vacuum lines, vent, driveshafts and linkage. I did not support transfer case on it's own, removed the 5 or maybe 6 bolts? and slowly pulled transfer case away from trans and lowered by hand. Not hard at all but maybe 6-8 hours start to finish including tool search and cleanup. I would support Jeep on four good jack stands to make it easier. Good luck. Almost forgot, I have a 1" body lift that made it much easier to reach top bolts on transfer case, maybe remove shifter boot for access.
__________________
kevyj87 '87 I6 5spd, 215,000+ miles, Herced, Nuttered, Weber, HEI, RE 4", 1" BL, 4:11's, np231, 33x12.5's, SYE & shaft, 1" brown dog mm, home made bumpers front & rear, Ramsey 8,000lb winch
King03Kev is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.