NSG370 Rebuild

[rlinares40]

Finally decided to open up the NSG370 I purchased for my project. The guy said it would come out of 3rd gear while driving, he mentioned no other issues. I took some pictures of the assembly on the stand and was hoping some of you who have rebuilt the same transmission would be able to tell me what needs replaced.


Shift Rail Guide: I know for sure needs to be replaced as the plastic is broken. Ordered the bronze guide plate from Whitbread Performance.

5TH-6TH Synchro Assembly: Looks fine to be but i could be wrong.

Reverse Synchro Assembly: Looks fine but could be wrong. Maybe the sleeve looks worn? The shift fork pads looked normal and were not broken.

1-2 Synchro Assembly: These do look worn/rounded.

3-4 Synchro Assembly: Look a little rounded so probably replace?

also how do you tell when you need to replace the synchro assembly vs just the synchronizers & friction rings?

 

[JMT]

I think you’re breaking ground here buddy. I haven’t seen anyone dig in to one of these complicated Mercedes transmissions on the forum.

 

[sab]

@rraulston rebuilt one a few years ago. Here's his build thread:

https://wranglertjforum.com/threads/it-has-begun-my-attempt-at-rebuilding-my-6-speed-nsg370.39045/

 

[freedom_in_4low]

Reverse looks a little rounded to me, I'd probably change it simply because that's one of the more common issues and is what led to me pulling mine out. If it's an 05 for sure, theres a TSB for updated reverse parts to fix a known problem.

Bent shift rails is another one I heard is a common problem. It may be secondary to worn synchros and then the driver starts being more forceful to complete shifts, making things worse because the bent rail won't push things all the way home. Just my thought process there.

I didn't take mine apart as I was in a rental at the time and didn't have a garage set up for such an undertaking. I just swapped it and sold it to a rebuilder as a core.

 

[Zorba]

See if the 1st/2nd gearset from the "wide ratio" version will fit!

 

[Willys LJ]

Following! I'll probably end up going into mine sometime. It's still shifting ok and staying in gear for now. Nothing like 6 speeds and 6 cylinders of cast iron goodness.

 

[JMT]

Geez, my reverse is a horror. I gotta do something. The job is a black box to me, so I’m afraid to attempt it.

 

[rlinares40]

See if the 1st/2nd gearset from the "wide ratio" version will fit!

do you have a link to the parts??

 

[rlinares40]

Geez, my reverse is a horror. I gotta do something. The job is a black box to me, so I’m afraid to attempt it.

The job doesn't seem too bad if you have the stand and case puller. Got a pretty good deal on eBay for both.

I looked at the Ax15 rebuild, the NV3550 Rebuild and the NSG370 rebuild and by far the NSG370 looks to be the easiest

 

[rlinares40]

Update: Picking up a 3 claw puller today to start pulling some of these off.

 

[Zorba]

do you have a link to the parts??

Nope. Finding out information about the so-called "Wide Ratio" version is virtually impossible. Apparently, it was used in Diesel Liberties? It has a lower first and 2nd gear which would be fantastic. Don't know if the 1/2 gear assy would drop into a regular tranny or not. Once could hope...

 

[bluescapegoat]

Nope. Finding out information about the so-called "Wide Ratio" version is virtually impossible. Apparently, it was used in Diesel Liberties? It has a lower first and 2nd gear which would be fantastic. Don't know if the 1/2 gear assy would drop into a regular tranny or not. Once could hope...

I've always wondered that myself. According to a couple unverified sources it looks like the ratios are as follows:

Close Ratio
1 - 4.46
2 - 2.61
3 - 1.72
4 - 1.25
5 - 1.00
6 - 0.84

Wide Ratio
1 - 5.01
2 - 2.83
3 - 1.79
4 - 1.26
5 - 1.00
6 - 0.83

That'd take my crawl ratio from ~91.5 to ~103. Not insubstantial.
I've got an old NSG370 from a 2.4 sitting in a barn a couple states away and always wondered if they were actually different ratios, given the case is actually different with a different bolt pattern and the 4 banger the last couple years came with 3.73s. I assume the internals are the same, but never looked into it.

 

[rlinares40]

I've always wondered that myself. According to a couple unverified sources it looks like the ratios are as follows:

Close Ratio
1 - 4.46
2 - 2.61
3 - 1.72
4 - 1.25
5 - 1.00
6 - 0.84

Wide Ratio
1 - 5.01
2 - 2.83
3 - 1.79
4 - 1.26
5 - 1.00
6 - 0.83

That'd take my crawl ratio from ~91.5 to ~103. Not insubstantial.
I've got an old NSG370 from a 2.4 sitting in a barn a couple states away and always wondered if they were actually different ratios, given the case is actually different with a different bolt pattern and the 4 banger the last couple years came with 3.73s. I assume the internals are the same, but never looked into it.

https://webshop.ganzeboom.net/mb716-6

Case looks different but the internal shafts should be the same I think...

They have their 1st gear as a 41T vs the Jeep one which is 45T

 

[rlinares40]

https://webshop.ganzeboom.net/mb716-6

Case looks different but the internal shafts should be the same I think...

They have their 1st gear as a 41T vs the Jeep one which is 45T

43T for the Sprinter Van

https://www.ebay.com/itm/1555716281...d=link&campid=5337789113&toolid=20001&mkevt=1

 

[Zorba]

I've always wondered that myself. According to a couple unverified sources it looks like the ratios are as follows:

Close Ratio
1 - 4.46
2 - 2.61
3 - 1.72
4 - 1.25
5 - 1.00
6 - 0.84

Wide Ratio
1 - 5.01
2 - 2.83
3 - 1.79
4 - 1.26
5 - 1.00
6 - 0.83

That'd take my crawl ratio from ~91.5 to ~103. Not insubstantial.
I've got an old NSG370 from a 2.4 sitting in a barn a couple states away and always wondered if they were actually different ratios, given the case is actually different with a different bolt pattern and the 4 banger the last couple years came with 3.73s. I assume the internals are the same, but never looked into it.

Way I see it, 1st gear is virtually useless as it is. Its not low enough to crawl (in 2/4-hi), but its really too low to use in normal traffic but you have to anyway because 2nd isn't low enough to start off in without using more clutch than I'd like. I'm wondering what life would be like with the "wide" ratios.

Another thing I've observed, the crawl ratio of this Jeep in 4-lo is roughly twice that of my beloved childhood GMC - BUT - the Speed Over Ground is about the same between the two as the Jeep idles twice as fast as the old GMC did. A lower 1st would help that, although it wouldn't be the same as the GMC's 7+ 1st gear ratio, but the xfer case makes up for that. *shrug*

 

[JMT]

The job doesn't seem too bad if you have the stand and case puller. Got a pretty good deal on eBay for both.

I looked at the Ax15 rebuild, the NV3550 Rebuild and the NSG370 rebuild and by far the NSG370 looks to be the easiest

You tempt me to break mine open and try to fix reverse. That’s all that is wrong with mine. Other gears shift like butter. Like I said though, a transmission is a black box to me.

I need to find out what a stand and case puller are. Also need to find what parts to fix the reverse. I’ve pulled the transmission once to replace the clutch. That’s it though.

 

[Artsifrtsi]

You tempt me to break mine open and try to fix reverse. That’s all that is wrong with mine. Other gears shift like butter. Like I said though, a transmission is a black box to me.

I need to find out what a stand and case puller are. Also need to find what parts to fix the reverse. I’ve pulled the transmission once to replace the clutch. That’s it though.

I fixed my reverse issue with a Mopar Crate NSG in 2013…

 

[Ericshere03]

Let us know how that whitebread brass guide works for ya! My 05 NSG Leaks from the input shaft seal, thinking of swapping it because my second gear synchro is a little worn. I was thinking of getting a later NSG from a JK which has a deeper OD (just a little) and over a decade newer, they share the same input shaft part number, so I assume the bellhousing/front housing is the only thig that needs to be changed ... I'd further assume that a "Wide" ratio liverty trans will work too because it too uses the same input shaft. Just a thought.

 

[hear]

@rlinares40 I'm thrilled you're tackling this. I'm just down the road from you if you want help or a 2nd set of eyes. I'm fascinated with transmissions, but I've only messed with automatics. Would love to tear into a manual.

 

[rlinares40]

Let us know how that whitebread brass guide works for ya! My 05 NSG Leaks from the input shaft seal, thinking of swapping it because my second gear synchro is a little worn. I was thinking of getting a later NSG from a JK which has a deeper OD (just a little) and over a decade newer, they share the same input shaft part number, so I assume the bellhousing/front housing is the only thig that needs to be changed ... I'd further assume that a "Wide" ratio liverty trans will work too because it too uses the same input shaft. Just a thought.

I believe the bolt pattern may be different between the TJ and JK's. On TDI Conversions (I'm doing a diesel swap) they list different adapters for the 4.0L and the 3.6L.