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NV3350 SWAP?

J

jeepxj21085

NAXJA Forum User
Location
joppa md
NV3550 SWAP?

im considering buying a nv3550 to swap intp my 1990 xj the ax15 is on its last leg. From what i can find out its a direct bolt in is this true same clutch,slave cylinder etc... what about the throwout bearing and shifter what do i use ????? THANKS
 
Last edited:
From what I've read it's a 1996 or newer bolt on.I swapped a 96' AX15 into my 91' and had
to do some mods nothing serious.Pilot bushing from AMC 304.The input shafts on pre 96' is smaller than nv3550/AX15 96+.I hoped this is a little helpful
 
1sickhick said:
From what I've read it's a 1996 or newer bolt on.I swapped a 96' AX15 into my 91' and had
to do some mods nothing serious.Pilot bushing from AMC 304.The input shafts on pre 96' is smaller than nv3550/AX15 96+.I hoped this is a little helpful
Click to expand...

EDIT: The bushing is for cj 304 73-78

JACK
 
jeepxj21085 said:
im considering buying a nv3550 to swap intp my 1990 xj the ax15 is on its last leg. From what i can find out its a direct bolt in is this true same clutch,slave cylinder etc... what about the throwout bearing and shifter what do i use ????? THANKS
Click to expand...



Very interesting.

Isn't the NV3550 the one in the new jeeps?

If so I would recommend using the newer jeep throwout.

Shifter... Get one and make it the way you want! its just a shifter...

I will be watching this thread as we are in need of a 5 speed for the 99'


XJR
 
i had to do something simular to that when i did my motor swap the 1990 pilot busing wouldnt fit in my 94 block the 94 pilot bushing was diffrent so in order to use the 1990 bushing i drilled out the crank shaft VERY CAREFULLY and it worked great
 
XJ Rubicon said:
If so I would recommend using the newer jeep throwout.
XJR
Click to expand...

X2 You have a Ford style system slave is in bell houseing.YOU will need everything from master cylinder to slave.
 
1sickhick said:
X2 You have a Ford style system slave is in bell houseing.YOU will need everything from master cylinder to slave.
Click to expand...

Not a problem, I put an 96AX15 in my 87' so I know the drill. =)
 
if it's an NV3550 out of a wrangler, and not a cherokee the transfer case will be slightly clocked up. It will hit the floor....Ask me how I know., I re-drilled the trans to re-clock the case so it wouldn't hit the floor. You can always cut the floor, but I chose not too.

I went from an '96 AX-15 to the NV. When I swapped it from the first 2wd AX-15 to the newer style AX with the bigger input shaft I used the pilot bearing from a newer one...No bushing for me. I Have swapped transmissions 3 times on the jeep and have used the same factory shifter on all of them. I have pics if you want them, it's not much. As of right now I'm running a 2003 NV3550 out of a wrangler, a hydraulic assy. out of a '96, and the shifter out of my '89

Justin
 
If you are set on going the NV3550 route, take some time to Google for 'gear selection', 'disengagement', 'clutch drag' problems that will cause premature failure. Our TJ had to have a new one after only 45,000 miles.

The theory is that when used offroad, the NV3550 is intolerant to heat build up that may cause the flywheel to distort. The symptoms take a while to surface, but by the time they do, the damage is already done and the synchros are permanently damaged. When we replaced ours we got a new flywheel, kevlar clutch and CPS from Hesco.
 
Vince said:
If you are set on going the NV3550 route, take some time to Google for 'gear selection', 'disengagement', 'clutch drag' problems that will cause premature failure. Our TJ had to have a new one after only 45,000 miles.

The theory is that when used offroad, the NV3550 is intolerant to heat build up that may cause the flywheel to distort. The symptoms take a while to surface, but by the time they do, the damage is already done and the synchros are permanently damaged. When we replaced ours we got a new flywheel, kevlar clutch and CPS from Hesco.
Click to expand...

So the problem is with the flywheel right? Causing drag on the clutch even while its disengaged?

Are there aftermarket flywheels Avalable?
Can't I just use the AX15 flywheel?


I'm starting to think I should just pickup another AX15...


XJR
 
I swapped out a perfectly good AX-15 for an NV3550 with 60K on it. The NV is cheaper too fix when chit happens.....and less complicated to re-build. I'll take the NV any day, Even over an NVG370 6 speed.

Just start gathering parts, and when you get it all then start on the swap.

Justin
 
Our first NV3550 had more than 300 hours use offroad with the transfercase in low ratio before it had 20,000 miles of road use. The engine never overheated during that time, but the slow speed use offroad provided enough heat soak to warp our flywheel. The Jeep was a 2001 4.0L TJ.

As I said, the problem we had was with our flywheel. That problem may be unique to our model year, a small range of years, or just some flywheels out of a batch.

Someone I know, also found they had a warped flywheel same way we did, replaced it with a new stock flywheel and a new NV3550 and the same thing happened again. Before fitting his 3rd NV3550 he installed the Hesco flywheel and it's been in there nearly 3 years now without a problem. Our new one has been in 2 years with the Hesco flywheel and clutch and it's never thrown 2nd gear or had difficulty engaging any gears.

In 2005 the repair parts we needed for our NV3550 cost more than a replacement transmission. If repair parts are cheaper now, that's certainly good news.

The NV3550 is a strong transmission. Our stock 2001 flywheel just wasn't capable of withstanding the heat from driving for long periods in low ratio. It's just unfortunate that the NV3550 ends up being the victim of another fault.
 
If my AX-15 ever goes out I'll probably put in a 3550, cuase I don't like how clunky the AX-15 is, even though it's a strong transmission.
 
Would it be possible to swap in an NV4500 out of a dodge pickup instead? I haven't heard of any problems with them, and you have assurance that your tranny can handle anything you can throw at it :)
 
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