View Full Version : tj-yj np231

dirt balls
05-01-2006, 07:15 PM
so i was under the jeep today making a big list of broken parts and came to the conclusion my t-cass might not be up to par dont think they work to good when the rear out put is pointing to the right tire :eek:

so heres my question if i take whats left of my tail shaft and rear out put housing will it fit and work on a 2000 tj tcass i got laying around it from the some motor tranny any one know

05-01-2006, 07:41 PM
Nutbars probably the only one that would know that answer !

Good luck !

05-02-2006, 01:36 AM
The case itself is pretty much the same but to use the yj stuff you will need the yj mainshaft rear bearing housing and extension housing

05-02-2006, 01:38 AM
use teh 231 for the calwer box an make a doubled setup[36][36]

dirt balls
05-02-2006, 08:00 PM
thanks for the help nutbar[cheers] im going to give it a try this weekend. i like the idea of the doubler setup but i think im going to go with a dana300 and build her up just got to find me one now ;)

dirt balls
05-03-2006, 11:16 PM
ok so i had some time tonight so i pulled my tcass turns out i snapped the main shaft:D . so this is my new crazy wack out idea ready for this one why cant i just bolt the tj cass straight in is there any reson i cant just use the tj as a straight swap it looks like it will work

05-03-2006, 11:27 PM
the tj case should bolt in the only thing you might have trouble with is the drive shaft on the tj the mainshaft sticks out of the bearing support and is sealed there then the driveshaft slips over it externally on the yj the mainshaft comes through the bearing support and into the extension housing then the driveshaft sticks into the extension housing onto the mainshaft and seals the unit. So you will probably have to find the tj driveshaft and it might fit or at least the tj slip yoke for the driveshaft, the yj one might fit have never tried that swap before I think the tj mainshaft is slightly shorter than the yj one.

The only other thing you will have to do is swap the frt output yokes on the t cases the one on the tj is for a cv drive shaft so it has unthreaded holes through the yoke for the bolts to hold the cv yoke and the holes are in the wrong position for the standard style driveshaft.

dirt balls
05-04-2006, 09:55 PM
thanks again for the help nutbar [cheers] im going to try and run my yj drive shaft and yoke for now ill let you know how it gose

dirt balls
05-06-2006, 10:54 AM
how much inwould travle should i have on my rear output yoke when sitting on flat ground any ideas

05-06-2006, 12:41 PM
Depending on how much lift you have if it is stock you should get about 1 inch of in travel from sitting at ride hieght to full compression.