JK NSG370 bellhousing pattern

[DirtyComanche]

I'm getting some conflicting info on this, is the JK 3.8L NSG370 the same pattern as the 4L/TJ applications, or is it the same as the KJ 3.7L applications?

 

 

I found a low mile JK NSG370 for dirt cheap...  No, I don't really like the NSG370, but it could be worth exploring.

[Jeep Driver]

Here's the skinny.........depends on what bell it comes with. 

 

http://www.novak-adapt.com/knowledge/transmissions/manual/nsg370

[DirtyComanche]

Here's the skinny.........depends on what bell it comes with. 

 

http://www.novak-adapt.com/knowledge/transmissions/manual/nsg370

 

 

I hate to break it to you, but Novak is wrong as often as they are right.  They also don't mention anything about this application (3.8L).

 

 

Edit.  They do mention the 3.8L.  My bad.  They don't mention anything useful though, other than it will bolt to it with the correct bellhousing.  Which could imply that the 3.8L used it's own bellhousing, or that they don't have a clue and didn't want to get pinned down on that one...

[johnj92131]

Found this:

 

http://www.pirate4x4.com/forum/jeep-non-hardcore/892870-5-speed-6-speed-swap-cps.html

 

and this:

 

http://www.jeepforum.com/forum/f11/nsg370-6-speed-cherokee-1018529/index2.html

 

Last post seems to have some good information:

 

Nsg370

Howdy, I currently have several transmissions on my garage floor, including a NSG370, NV3550, T5, SR4, TF727, AX15, TF904, and an AW4.

The NSG370 and NV3550 share nearly identical flywheels, but the crankshaft position sensor is in a different spot. On the NSG370 it is a round hole on the side with a round sensor and on the NV3550 and all the other 4.0 transmissions the sensor is a rectangle on the top of the bellhousing. If you look closely at the flywheels the notches are the same, but they are clocked differently. You must have a NSG370 flywheel to match the transmission for the sensor to work properly.

The shift linkage for the two transmissions are identical and interchangeable. The slave cylinders are almost identical, but very slightly different. The NV3550 has a plastic spacer on the end of it that adds a quarter inch of thickness to the flange. The NV3550 slave cylinder does not have that plastic piece and they should be interchangeable but I'm not totally sure. I put the two next to each other and they have the same dimensions. My NV3550 slave is plastic and the 370 is metal. You're best buying the right slave cylinder to match the trans. The connection (weird o-ring and rod setup) on the end is exactly the same and the rest of the clutch system can be left alone.

The pilot bearing for the two is exactly the same. If you are putting it behind a 258 crank it will still work just fine. There is a little extra lip on the 4.2 than the 4.0, but it doesn't effect anything. The earlier transmissions like the T5 are a smaller bore nose with the same splines. Clutches should be totally interchangeable. When you order the pilot bearing make sure to get the whole assembly. Its a bearing inside of an aluminum ring that get pressed together into the crankshaft. When I got one at Autozone only the bearing part came, and to remove it you will damage the adaptor so that part was totally useless. I then got it at Advanced, and the whole adaptor and bearing part came as an assembly. Thats what you need.

All 4.0 flywheels are a quarter inch less thick than 258 and AMC V8 Flywheels. I don't know if the slave cylinder will adjust enough to make up for it. I would love to see if someone has successfully installed one behind a V8. The V8s cannot use a neutrally balanced flywheel and you don't have the option of putting a 4.0 flywheel on a V8, even tho it will bolt up. I ditched the NV3550 bellhousing and used a T5 bellhousing with stock V8 thick flywheel and shift linkage and then used an Advance Adaptors adaptor that bolts between the NV3550 and stock T5 bellhousing. That setup lets you retain the original mechanical or hydraulic clutch linkage you already have. I used the original clutch assembly except for the new pilot bearing. The integral bellhousing on the NSG370 doesn't allow that option and I used mine behind a 4.5 inline six.

The AX15 with an internal slave cylinder will bolt up to the NV3550 external slave cylinder bellhousing with very slight modification. I like the AX15 the best, it feels less like a truck to me, but its weaker than the 370 and the 3550. All three of those are much much much stronger than a T5. Even a "World Class" highly modified T5 is junk compared to all three of them, and many people have had T5s behind AMC 360s without trashing them. If you're gentle all these transmissions will last forever.

-Dave Spillane-
AMC Eagle SX4 with 401 NV3550
AMC Eagle SX4 with 4.5 NSG370 MPI
CJ8 with 4.2 NV3550
Soon an AMC Eagle SW with SD33T and NV4500

[DirtyComanche]

That's some interesting info.  For a Renix application a guy would have to make a hole/mount for the CPS, or get one of the now non-procurable CPS relocation kits, or perhaps there is some other option.

 

Looking at it, it looks like it would be something of a PITA to swap in a transmission that I honestly don't feel is much better than the AX-15 or NV3550.  If they had actually made it a double OD transmission I would be more likely to try it.

 

Now, that said, I COULD put it in my severely underpowered J-truck that currently has a 258/Turbohydraslushomatic-400/CyBorgWarner Quadrainsanity combo.  I am debating picking it up either way as if nothing else it can live in the shed (it can keep my spare AW4 company) and be a spare for my JK.

[johnj92131]

I don't see any real improvement over the AX-15, just a slightly steeper first gear and a lesser overdrive ratio.  Maybe a replacement for the AX-5 in a 4 cylinder?  But even then, the AX-15/NV3550 would be a safer path.

[88whitemanche]

This guy was attempting the swap but not sure if he finished it....

 

http://comancheclub.com/topic/49211-comanche-chief-aged-to-perfection/page-2

 

There's another one on jeep forum that I'll search for the link now and edit back...

[Cooky]

@RAY 2446420 are the bellhousing bolt patterns the same.  Nowhere can I find that answer.  And after wasting $1200 with Novak on my last project I will never trust them again.

[ghetdjc320]

The NSG370 has an integral bellhousing. The actual location of the cps has been a non issue for conversions with the HO flywheel since it uses 3 sets of equally spaced reference points and the CPS was just at the next set of marks. I know Renix also uses 3 marks equally spaced but I’m not sure if their position is the same as the HO.