I have a 1994 Jeep Grand Cherokee Ltd 5.2L with a NP249J TC. I have removed the front driveshaft due to the TC going ka-fluie with clunk-clunk-clunk during turns. So I have begun the process of finding out how to correct the situation. I read this thread and I have been searching for a replacement TC. I have read early in this thread that the NP249J TC has a 1.55" input shaft.
Recently I purchased a NP231J TC that has a 0.840" input shaft out of a 2000 Jeep Cherokee Sport. I know I can bolt the TC to my 46RH tranny.
BUT... will the 0.840" input shaft engage the 46RH tranny input shaft?
If not can I exchange the input shaft in my NP249J TC with the input shaft with my NP231J TC? Will the NP231J TC operate correctly with the 1.55" input shaft in it?
I read that the NP249J and NP242J input shafts can be exchanged successfully. Where does all of this leave me with the NP231J TC?
I'm certainly not an expert, and I haven't even performed this swap yet, but I've read the opening post to this thread a few times.
According to everything I've read and discussed with other members, you should not have a problem swapping the 1.55" input shaft from your 249 into your 231.
The problem I think you might run into is the annulus gear cut change which apparently occured mid-94. You wrote that you have a 94 GC but have a replacement 2000 231 t/c. I couldn't find anything in the post discussing whether a front case swap would be possible btw 249 and 231.
In addition, JrMechanic notes that the shift indicator sensor from the 249 will not work in the 231.
I almost lost the 242 that I was planning to use, and started even considering getting a 231. Thankfully, I'll be getting my 242 in 3 days. I have a 93 5.2 Ltd, and was lucky to find a 242 built in jan 94. All in all, I would think this thread indicates that it is a much more difficult swap to the 231.
Here's a question I don't think has been directly addressed, which I now need answered.
The 242 I'm looking at getting is an ISY, but doesn't have the actual rear yoke (i'm referring to the clamp thingy which looks like a robot's hand. Is yoke the right word?). It has the front output only. I've seen them with and without the rear (mostly without)
From what I gather from the FSM, the front yoke is attached to it's mate on the front drive shaft by 4 bolts, which face the t/c. Located here 3 1/4" from the t/c:
I assume these are unbolted and the front driveshaft will then be disconnected.
As for the rear, I don't see any bolts which marry the yokes together:
It would seem to me then, that the rear drive shaft must slide in & out of the rear housing of the t/c, for installation and removal. If so, where does the room come from to do this, without disconnecting it completely from the axel? The FSM only mentions disconnecting the driveshafts at the t/c.
Am I way off?
@ tinow, where exactly does the rear ouput seal go (haha)? I couldn't find it in the FSM. Is it the red bit located 7 3/4" on the external housing of the ISY where the rear driveshaft meets the t/c?
Also, regarding refilling the transmission and t/c after installation. Is this just as easy as topping up the level for the trans in the engine compartment, and filling the t/c up to the bottom of the fill hole plug?
You will have to remove the rear drive shaft from the rear differential and then slide it out of the transfer case. Yes that is the rear output seal of the transfercase at the 7 3/4" mark, but when you swap to a 242 transfer case, it has an external slip yoke which you will want to get a drive shaft that will correctly work. Yes topping off the trans fluid as putting fluid down the pipe from the engine compartment but do it while the engine is running and fairly well warmed up, and yes you just fill the transfer case up through the fill hole until it comes out. As far as looking at used transfer cases, as long as you can shift through each mode and the input shaft turns the outputs you should be fine, you'll know if doesnt feel right. I'd wouldn't worry about it being stuck in 4hi right now until you swap in the 242 and just make sure all the linkage freely moves once you dis-connect it from the transfer case.
Just wanted to say: This is the best forum with the nicest and most patient members i've seen, and I'm proud to be a member. Next this thread BLOWS my mind! It's soooo good and years long too. We can all use it and Jr Mechanic gave us better info than anyone could ever hope for. Like to advise new folks to this thread to PLEASE start at pg. 1 its all there for real. This info could easily be sold and we would all buy it. God bless