BA10 to NV3550 swap

[Oizarod115]

anyone else blessed with this amazing peice of french engineering?

 

i've decided id really rather not wait for the BA10 in my truck to crap out and looking at tranny swap options the NV3550 looks better than a AX15. anyone tried/done this?

 

any opinions on which is better? (AX15/NV3550)

 

-nick

[Pete M]

The 3550 is newer and stronger, so I guess that makes it better. Either one is a good choice (as long as the trans is in good condition of course). Pay attention to the spline count of the tranny-to-Tcase shafts (the 3550 will be 23, your t-case is 21) and TJ/YJ trannys are different (can be a good thing or a bad thing depending on what you're looking for).

Jeep on!

--Pete

[Eagle]

Having driven all three, I think there is no comparison. The AX-15 is stronger than the BA10/5 but, IMHO, shifts harsher and makes more noise. The NVG3550 has a much lower first gear than either one, is stronger, and shifts incredibly smoothly. It is also quieter when driving. It does have one peculiarity -- when sitting at a light in neutral with your foot off the clutch, there is some "chatter." The techs at my Jeep dealer tell me that's typical and not cause for concern. Sounds almost like a sloppy release bearing, but they tell me it's actually the tranny.

 

It's definately the way to go if you have the $$$ to do it. Remember that it won't mate to a 21-spline transfer case, so you'll need both boxes.

[Stumpy]

i love the 3550 that is in my TJ and the only bad thing bout it is the chatter while in neutral but i put royal purple in and it has gottin a lot more quite.

[Pete M]

If I remember this right (what are the chances of that?) The TJs got a slightly different 3550 than the XJs. Something about a different cut in the gears (plus the typical differences of course).

Jeep on!

--Pete

[Oizarod115]

yeah, i was lookin at a kit on advanceadapters or highimpact both came with new input gears for my np231 so i wasnt real concerned about the t-case splines not matching

 

you say XJs had different 3550s than TJs?

is this cause for concern or is it just shift characteristics and the like?

 

thanks for the advice

-nick

[87manche]

If the 3550 for the TJ is anthing like the AX-15 for the tj then the shifter is different, and I think the bellhousing is different. I've been looking for an AX-15 myself, and the TJ ons have some differences i how they bolt up.

[Oizarod115]

so if i buy a kit with the bellhousing and all that will it still mate up to my 4.0 i6? i wouldnt think the bolt pattern on the engines would be different

 

and does that mean floorboard modification if the shifters are different?

[Pete M]

The TJ transmissions are different in many ways, clocking of the t-case, shifter tower, t-case shifter linkage style, trans mount, etc. The XJ one is a direct fit. That being said, I have a 99 TJ AX-15 in my 88. Go to picturetrail.com/petermontie and look in the drivetrain folder.

Jeep on1

--Pete

[Vandenborg1]

So I'm trying to get a list together on doing an nv3550 swap in my 88 mj but its currently 2wd so I'm trying to figure out what my best option is here. What t-case? will I need a custom driveshaft or can I buy one somewhere? Will my bell fit or will I need an adapter? Any other recommendations i missed? 

[Eagle]

First, does your '88 have a 4.0L engine? If it's a 2.5L, you can't do the swap.

 

Assuming you have a 4.0L, the BA10/5 uses an internal slave cylinder/release bearing. The NV3550 uses an external slave, so you will need the 3550 transmission and the bell housing. Since you will need both, you will not need an adapter.

 

I don't know about the driveshaft length.

[omega_rugal]

save the BA10/5 for some poor ZJ with a bad 42RE, i have seen many ZJs in good shape being thrown to the trash because the transmision suddenly loses 4th gear and Reverse...

[schardein]

I have an NV3550 in my CJ.  I had an XJ one in it, then when I swapped in a Chevy 5.3, I used a TJ one.

 

As already stated, I think the t-case clocking is different.

 

The shifter stub (on the trans shift tower) for the XJ has a slight "s" curve to it, which moves it backwards slightly.  It is square, and the shifter lever has a female end that slips over it and is secured by a set screw.

 

The TJ shifter stub is straight, and is a round with a flat on one side.  It also has a threaded hole going straight in the middle.  The shifter stick has a rubber isolated piece on the bottom that slides onto the stub, and a torx head bolt goes straight in securing it to the shifter stub.  The stick is actually welded to the steel encased rubber isolator.  

 

First pic is shows the shift tower with curved stub, and non-isolated stick.  Second pic shows rubber isolated stick.  Random pics from google.

 

I didn't try it, but I bet you could swap shift towers if one worked better than the other for swap purposes.  

[schardein]

OK, correction/addition to the above post.  Something kept itching at the back of my mind, and it finally hit me.  That first picture above isn't an XJ shifter.  Those must be 2 different versions of a TJ shifter.  

 

Here is an XJ shifter on a NV3550.  The base still has a square stub, but a slightly different bend.  Shifter is rubber isolated, shorter, and points more to the driver.  Uses 2 bolts/set screws to secure to the stub.