Any NSG370 experts out there?

[williambmac]

Shortly after changing the fluid on my transmission 6 months ago, I started hearing a gear whine that has gotten progressively worse. I just drained and refilled with Redline and the noise is still there. The fluid came out clean like I just put it in.
The noise is definitely in the transmission. I was considering tearing the transmission down and rebuilding it, but the parts are expensive.
A friend of mine has a transmission that he got out of a wrecked JK that only had 4k miles on it. I know the bellhousings are different and a 3.6 transmission won't bolt up to a 4.0.
I looking to see if anyone can confirm if the internals are the same.
I was entertaining the idea that I could just swap the internals over into my LJ.

 

[fizzlebottom]

Just out of curiosity, are you just hearing this from inside the cabin or is it from the outside as well? Are getting more heat down in the footwell around the transmission tunnel?

I'm only asking because I was getting a lot of noise all of a sudden in the cabin, as well as heat, and learned that it was a torn inner shifter boot. Just want to make sure this isn't your issue before you go tearing the transmission out.

 

[freedom_in_4low]

A friend of mine has a transmission that he got out of a wrecked JK that only had 4k miles on it. I know the bellhousings are different and a 3.6 transmission won't bolt up to a 4.0.
I looking to see if anyone can confirm if the internals are the same.
I was entertaining the idea that I could just swap the internals over into my LJ.

I haven't come across any examples of this being done. At one point I thought I read there was something different on one of the shafts that would prevent a total internals swap but it was in the context of getting a different ratio for one gear and I haven't been able to find it or any evidence that the ratios are different so it may have been balderdash.

You'd be taming new frontiers if you did it and pulled it off, which would be pretty cool, but if downtime is a problem you might need a backup plan in case you find something like a countershaft having a journal in the wrong place.

 

[williambmac]

Just out of curiosity, are you just hearing this from inside the cabin or is it from the outside as well? Are getting more heat down in the footwell around the transmission tunnel?

I'm only asking because I was getting a lot of noise all of a sudden in the cabin, as well as heat, and learned that it was a torn inner shifter boot. Just want to make sure this isn't your issue before you go tearing the transmission out.

I get what you're saying about the torn boot. I had that issue a couple of years ago. I ponied up the big bucks to replace it.
This is definitely in the trans and it gets worse as it heats up.

 

[williambmac]

I haven't come across any examples of this being done. At one point I thought I read there was something different on one of the shafts that would prevent a total internals swap but it was in the context of getting a different ratio for one gear and I haven't been able to find it or any evidence that the ratios are different so it may have been balderdash.

You'd be taming new frontiers if you did it and pulled it off, which would be pretty cool, but if downtime is a problem you might need a backup plan in case you find something like a countershaft having a journal in the wrong place.

I spent a couple hours last night searching and I haven't come up with anything either. My backup plan is a call to High Impact gear.

I was going to just rebuild it, but when you start pricing out parts you easily exceed the price of a High Impact unit.

 

[P man]

Here's the problem with the nsg370..the shift fork assemblies always need replaced and they are expensive. They do interchange across the tj to jk line though. In the end you will find it cheaper and less frustrating to buy a reman or swap to an ax15.

 

[P man]

I spent a couple hours last night searching and I haven't come up with anything either. My backup plan is a call to High Impact gear.

I was going to just rebuild it, but when you start pricing out parts you easily exceed the price of a High Impact unit.

Also don't forget about specialty tools required to rebuild

 

[williambmac]

Here's the problem with the nsg370..the shift fork assemblies always need replaced and they are expensive. They do interchange across the tj to jk line though. In the end you will find it cheaper and less frustrating to buy a reman or swap to an ax15.

This I know. The shift fork is expensive AF and they are indeed a crappy design. Everything else for this trans is also expensive. German engineering for you.
Having had an NV3550 and an AX15 in the past, I actually prefer to stick with the six speed. I'm not saying there is anything wrong with the AX15. I just like the six speed on the street.

Also don't forget about specialty tools required to rebuild

I have access to the specialty tools required for the job. I just need to confirm that all the internals are the same. I may contact High Impact and pick their brain.

 

[JKP]

The OD ratio is different on the JK. It would drop the RPMs more than the TJ version.

Have always wondered if the internal swap would work as that would mean you could use Liberty and JK internals in our cases. More spare parts.

 

[williambmac]

The OD ratio is different on the JK. It would drop the RPMs more than the TJ version.

I would be fine with that. I'm turning 3600 rpm's @ 75mph with my 5.38's.

 

[JMT]

This I know. The shift fork is expensive AF and they are indeed a crappy design. Everything else for this trans is also expensive. German engineering for you.
Having had an NV3550 and an AX15 in the past, I actually prefer to stick with the six speed. I'm not saying there is anything wrong with the AX15. I just like the six speed on the street.



I have access to the specialty tools required for the job. I just need to confirm that all the internals are the same. I may contact High Impact and pick their brain.

I’ve looked at all of this. I just can’t remember the details of the compatibility of internals. I ended up deciding that I’d go with the High Impact with all the upgraded internals.

 

[JKP]

It looks like you would need to swap out parts 31 and 51 to change the OD ratio.

I have read that the input shafts are different lengths, so you would probably have to use the TJ input shaft.

 

[Zorba]

I would LOVE to be able to swap in the "wide ratio" 1st and 2nd come rebuild time. That what should have been there in the first place!