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moonshinefuel 11-10-2011 06:52 PM

I am drilling in three stages, smaller drill bits to larger. This is the second stage, going out to buy the largest drill bit I need. It's coming out really good.

moonshinefuel 11-10-2011 10:47 PM

This transmission is burly, and physically larger than the ax5. Some have reported they have been able to fit it in the original shifter tub holes without trimming the tub. Setting mine up in there to get an idea, I have trimmed my tub some to allow for an easier fit. Approx 2 inch area behind the original shift tub holes.

moonshinefuel 11-11-2011 02:02 PM

I am going to be posting a few images of the clutch I am going to use. I stated earlier in this thread that I am going to use the primarily Dakota clutch system. I am not going to do that, at this time anyways. I am in agreement with RollinThunder that it really does not matter that much in his view. Though, I think the dakota pressure plate might be slightly better, its probably negligible. So the 20 dollar advance adapter bushing I am using in my ax5 flywheel, with the ax5 pressure plate, and the converted clutch disc, with the original throughout bearing as well. One thing to take note on, is the AA bronze bushing fit fine when not inserted into the flywheel, but as soon as I pressed it into the flywheel, the I.d. of the bronze bushing was compressed some, enough to be a problem for the input shaft to fit into upon install. I have since honed the bushing out just a little, until a nice fit was established which was done with a fine cylindrical sandpaper rotary tool bought at Harbor Freight Tools for ten bucks. It did not take much, just a tad bit of honing. Again, with fine sandpaper tube fittings. At first, the pilot on the input shaft would not even go into the flywheel bushing, but again, that was an easy fix. (just take flywheel off of the engine after you press the bronze pilot into it, and test it on the input shaft of the nv3550)
Just like RollinThunder, I had an old pilot bushing alignment tool hanging around that did not fit the splines for the disc, but the o.d. was there for a snug fit, and the pilot centering was too small, so I wrapped electrical tape around the pilot tool tip to bring it to .750 for centering in the pilot bushing. So I made the old alignment tool work excellent. I also soaked the pilot bushing in oil for quite a while.

moonshinefuel 11-12-2011 05:51 PM

Today am swapping in a 23 spline compatible gear for the t case. I know its been mentioned before, if you have a complete 23 spline t case ready to bolt up, you will save yourself more work, and time. This is the second time I popped open a t case, its not real difficult, just time spent, that's all. Lots of gasket seal to clean up and re-apply as well.
There are some good 231 write-ups out there. I am not going to go into all the aspects if this because of that. But, I will discuss a few things regarding my experience. Get a good set of transmission snap ring pliers, not the small ones, the larger ones. There is a snap ring that holds the gear shaft and keeps it in the case. When you remove the 4 ten mm bolts and remove cover, you will see it. I set my case half as you will see in the image facing down. Put some rags, or something under on the inside to catch the planetary. Apply the pliers to the snap ring and expand the ring enough, the weight of the planetary will simply pull it down by its own weight, and its out. I find it works a lot better than trying pull the ring off the shaft. Just let the shafts weight do the work. Again, it works excellent. In the above image, there is a larger clip ring that needs to be removed. When you look into some write ups on that ring, some say it is troublesome. I found it easy to remove with small a small pic tool set, basically another harbor freight tool item, they look like dental tools with various angled pic tipped instruments. Made quick work of this, real easy.
Regarding planetary gear swap compatibility, this seems to be a subject of its own. Through some research I will explain this as best as I can as follows.
It is my understanding that the gear cut changed somewhere mid stream 1994. I do not think you can see the difference with the average eye. But your t case will know the difference, and you will hear it, and more. So, I found that three sets of numbers that can be found on the t case circular tag is deemed to be compatible with the post 95 t cases. If your 94 or 95 case has any one of these numbers, it simply means the gear cut is compatible with post 95 input t case gear shafts. I am putting a 97 t case gear in my 95 t case.
So, on my t case, on the image above, the tag shows my t cases assembly number, which is 52098361. What that means to me is that it is compatible with post 95 np231/ 23 spline shafts, as my replacement shaft is from a 1997 np231 t case.
To quote another source; Because of the differences in the cut of the gear, as a general rule, one should not interchange 1987-1993 gears with 1994-present gears.
But that is stated as a general rule, not a definitive delineation.
A good website that discusses this subject is here: I have the later narrow bearing late gear cut on my t cases. One Thing I don't see mentioned though, is the case bearing that supports the gear/shaft. I had to swap out the case bearing with the shaft. They both are the narrow bearing style, but, there was too much play for shaft fitment into the bearing housing I.d. NVG states 40 something input gear variations, and swapping these gears has been described as elusive, and tricky by another source.
I have spent way too many hours on my T-case alone. I had to pop it open a second time to swap the bearing after noticing the above mentioned problem. I think its right now, but its concerning. This is why I am stressing get a complete 23 spline t case ready to bolt in at the same time, or before the swap if you can, and do your best to avoid splitting the t case for an input gear swap.

moonshinefuel 11-14-2011 10:00 PM

Here is a 1995 Yj factory skid plate. The top slots fit my ax5 transmission mount bolts. (top slots are closer to front of jeep)
Below, in this image, are the rear slots on the skid plate. At this time my engine is still supported, so its raised up a little from dropping onto the plate. But, the nv3550 is now installed onto the engine. This is where the mount is going to, and does, rest on the skid plate, right in the center of the rear slots, a perfect fit on the plate.
Below is an image of where the shifter housing rises up through the tub floor shifter hole. It comes very close, and rubs up against the metal around the rear side of the hole metal shift boot securing ring. You might want to trim about a half inch off selected areas, but more than that right now seems unnecessary. You will want to remove the shifter stub housing on top of the transmission, the.4 small bolts, as it will get in the way when its time to put the transmission up in there. Not a big deal, just bolt it back on when transmission is in place. I did more cutting than what was necessary to the tub, but that gives me a little more view down there from topside I guess. The metal flap actually is down about an inch more than what you see in the image, I cut it on one side, and it is flapped.up a bit. And what you don't see is about 2" that I notched out behind the shifter in the tub, behind that flap.
Below is an image of how my stock four cylinder exhaust bracket worked out mounting into the ax15 torque arm bracket. It fit right into the bushing to support my exhaust pipe. I was surprised at that. It was a good thing to see how that worked out.
Below is an image of the torque arm bolt holes in the ax15 plate, and in the skid plate below it. They align perfectly, the only thing I need to do is put some washers in the topside of the skid plate under the bushings. Fits really well though.

Opihi59 12-14-2011 02:05 PM

I have updated my IMG codes for photos that were not showing up. Anyone is welcome to inform me if I have missed any in this valuable thread, or in any others. My apologies to Moonshinefuel for having left these holes in his FAQ thread. :wave:

moonshinefuel 12-15-2011 01:40 AM

Thanks for checking in, and updating the codes, appreciate that.

Mr.ThunderMakeR 07-09-2012 12:46 PM


You guys still around to answer some questions? I'm just beginning a similar swap on my 91 YJ, except I'm doing a Rubicon Tcase as well, so its AX5/NP231 to NV3550/NP241OR.

My first question is about the clocking angle issue. I'm trying to avoid this issue altogether if possible. From what I understand, the problem is the clocking is different between Wrangler NV3550's and other Jeep NV3550's. Is this true? So if I make 100% sure I'm getting a TJ transmission, I shouldn't have any clocking issues with the NP241 correct? I will also be doing a 1" body lift, so this might negate the clocking issue anyways.

My next question is about the clutch setup, you switched your plans so many times I lost track of what the final plan was. Will this setup work?

- Dakota Bellhousing 96-98
- Centerforce Clutch
- Advance Adapters Pilot Bushing (p/n 716167)
- Stock YJ 2.5 Flywheel (resurfaced)
- Stock YJ AX-5 Pressure Plate
- Stock YJ AX-5 Throwout Bearing
- Stock YJ AX-5 Clutch Release Arm
- Pre-Bled YJ AX-5 Clutch Master/Slave Combo (External Config)

And thanks for the great thread!

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