Who Has Bought a Rebuilt NSG370?

[g.hayduke]

And the fact that they already had a TSB by February of 2005 for a transmission first released in MY 2004 means a good portion of them were not going to wait until warranty expiration to pop up.

I've been reading everything I could find on the NSG370 and its problem with reverse since I bought my '05 about 5 years ago. Most if not all the reports I've read have the issue surfacing well beyond the warranty period. When a TSB was published has very little relevance to what portion of repairs were done under warranty.

The warranty on my '05 was only 70K miles. My NSG370 never popped out of reverse until it had about 105K on it, about 35K beyond the warranty limit. Based on my reading, this is pretty typical. So I doubt they had much concern about shipping potentially bad units that would likely never come back under warranty. If a few did come back under warranty, that's the cost of doing business.

 

[g.hayduke]

Pix/procedure?

See post #53. Looking from below left side of transmission. It's just a 1/4" street 90 and a barb fitting, 1/4" NPT to 3/8" ID hose, then 3/8" fuel line hose with a vent cap terminated as high as possible on the firewall or wherever you want to put it.

Procedure: Drill and tap a hole in the shift tower being careful to avoid metal chips getting into the mechanism. Keep the hole as low as possible to avoid interference but still have room to screw in the street L.

 

[freedom_in_4low]

I've been reading everything I could find on the NSG370 and its problem with reverse since I bought my '05 about 5 years ago. Most if not all the reports I've read have the issue surfacing well beyond the warranty period. When a TSB was published has very little relevance to what portion of repairs were done under warranty.

The warranty on my '05 was only 70K miles. My NSG370 never popped out of reverse until it had about 105K on it, about 35K beyond the warranty limit. Based on my reading, this is pretty typical. So I doubt they had much concern about shipping potentially bad units that would likely never come back under warranty. If a few did come back under warranty, that's the cost of doing business.

I think the TSB issue date has more relevance, because it means they'd had enough of them come back within the first year to know it was a real issue, develop a fix for it and then acknowledge it by publishing documentation of it. It may have been a minority of the 48,000 NSG370's they shipped in TJ's that year, but it was enough for the data to come back from dealerships in large enough quantity to notice. I would think that would have had to take several hundred going tits up before MY 2005 production had finished and very few would have had more than 20k miles on them by that point.

EDIT: Did some googling and found reports of NSG370 slipping out of gear (first mainly) in Chrysler Crossfires. One of the complaints was dated 11/2003, with only 1500 miles driven on an '04 model.

More in support of your assertion than mine, my 2005 LJ with the NSG had no reverse issues at all when I sold it in September 2012 with 69,395 miles (unrelated, but for less than I paid for my 06 with 119k in November 2020 ).

 

[g.hayduke]

And the fact that they already had a TSB by February of 2005 for a transmission first released in MY 2004 means a good portion of them were not going to wait until warranty expiration to pop up.

Everything I see says the NSG370 debuted in a wrangler in MY 2005, not 2004. Seems like they were putting known potentially defective transmissions in almost from the beginning.

Given how few seem to have this problem with low miles, I doubt warranty returns on '05s triggered the TSB.

 

[freedom_in_4low]

Everything I see says the NSG370 debuted in a wrangler in MY 2005, not 2004. Seems like they were putting known potentially defective transmissions in almost from the beginning.

Given how few seem to have this problem with low miles, I doubt warranty returns on '05s triggered the TSB.

A wrangler yes, but they started using it in the Chrysler Crossfire in 2004. Development testing would have long since closed before the first 05 TJs and KJs rolled out of assembly. If it didn't come from warranty claims then they knew about it from testing and misjudged how frequent it would be, or knew how frequent it would be and deemed it acceptable. If it's the latter it kinda makes me mad, but sadly it falls in line with the quality of engineering they were doing at the time when I consider the OPDA, PCM, and fuel filler issues that plague those model years as well as my understanding of the culture at Chrysler during the Daimler years. (my 05 DID have fuel filler and OPDA issues that Chrysler was willing to do jack $#!+ about)

And it only strengthens my confidence in the decision to swap in a transmission that shares its guts with Toyota, when they were peaking in the 1980s, rather than something the Germans (who seem to have grown a large tolerance for automotive mediocrity over the past 3 decades) just tossed in there to save a few bucks without actually proving it out.

 

[freedom_in_4low]

FYI for anybody considering tackling their own TSB reverse fix, the kit is (of course, because Chrysler) discontinued, including all the superseding versions out to AE.

05175903AA Kit, Reverse Gear - 4x4 or 4x2 (inc. internal
shift subassembly, reverse gear, reverse
syncrho sleeve, reverse blocker ring,
retaining snap rings, oil seals, and counter
shaft seal plug )

I haven't been able to find it in stock anywhere. I've found some of the parts individually but not all of them.

 

[Claytone]

Has anyone just swapped the internals out of an 07+ into one of our cases? I do see low-mile take-outs pop up for relatively cheap.
I may give this a shot sometime.

 

[freedom_in_4low]

Has anyone just swapped the internals out of an 07+ into one of our cases? I do see low-mile take-outs pop up for relatively cheap.
I may give this a shot sometime.

haven't been able to find it again, but I seem to remember coming across someone who said there was something about the inside of the case that made an important part of the internals not swap over. Might still be worth a shot though.

The idea of not casting a case and a separate bellhousing makes no sense at all to me. Seems like it ought to be more modular and cost effective to cast a single box that you can use for decades and just change bellhousings based on what engine you want to put it on. Maybe it's just a manufacturer thought process. For all I know all Mercedes block bolt patterns are the same and it never even occurred to them to change it.

 

[Claytone]

The Benz patterns are the same as I remember. That transmission was in a lot of non-US vehicles. The 163 in the part number denotes it was first developed for the first generation M-Class 163 SUV chassis. non-US only since there were no manuals available here.
I don't try to make sense of what the MFGs do, it rarely makes sense from our vantage point.

 

[freedom_in_4low]

I don't try to make sense of what the MFGs do, it rarely makes sense from our vantage point.

Ingersoll Rand modeled their entire product development process after Toyota, so I just get into the headspace from when I was a design engineer for them for 5 years and I can almost always make sense of it, and it even becomes intuitive...But it breaks down a lot when I try to apply Toyota logic to Chrysler. They do a lot of stuff that doesn't make sense. I think it says a lot about both manufacturers that Toyota has used their Aisin made, R series transmission family (that the AX15 is based on) in dozens of models spanning nearly 4 decades, while Chrysler didn't manage to keep a manual transmission or an ignition system in the TJ for more than 4 years. To me that's indicative of whether the company commits the bulk of their engineering resources to new product development and making sure the next model released is as good as they can make it, vs putting the resources toward "value engineering" products already in production looking to save a few bucks per unit.

Don't take this as being a Toyota fanboy...I think they've been producing the most boring and uninspired vehicles in the industry since the mid 1990s but they have among the best, if not the best, approaches to engineering a large volume, complex, configurable product.

 

[Claytone]

Chrysler changing hands constantly doesn't help their continuity either.

 

[Ericshere03]

Since we're talking about this - I'll ask the question that nobody seems to have an answer for, but maybe something's changed. If/when I need to rebuild mine, I'd be *VERY* interested in the so-called "Wide Ratio" version - apparently used on Diesel Libertys or some such. It has a deeper 1st and 2nd gear. Are the parts to accomplish this available, or are they unobtainium?

Lots of people have asked this question, nobody seems to know much about it...

I would “THINK” that any Jeep NSG will work if you swap the proper input shaft, throw out bearing slide collar and “bellhousing” (front half of transmission case)… I had it in the back of my mind to someday swap a 2018 JK transmission when mine bites the dust. It has the same ratios but a deeper overdrive.

In my head this should work, plus we can scavenge JKs for replacement transmissions and have all the updates they made along the way.

I’d like a deeper overdrive so that rehearing more aggressively will result in better highway manners; eg 4.88 with 33 or 5:13 for 35

 

[JMT]

@g.hayduke how is the High Impact NSG-370 doing?

 

[g.hayduke]

@g.hayduke how is the High Impact NSG-370 doing?

No complaints. I'll try to check how many mile since the swap when I get home. Probably 10K ish.

 

[g.hayduke]

No complaints. I'll try to check how many mile since the swap when I get home. Probably 10K ish.

@JMT
It's been in for 18K miles. No issues. Does it shift like my old TSX? No. Is 5th a little vague at times? Yes but probably normal.

Do I wish I'd gone with an AX15? No. I like the 6 speed ratios. And with the 4:1 low, it's a good combo for my usage.

The only issue I ever had with it was with reverse. The rebuilts all have the updated parts that eliminate the inherent reverse issue on the early specimens.

 

[JMT]

@JMT
It's been in for 18K miles. No issues. Does it shift like my old TSX? No. Is 5th a little vague at times? Yes but probably normal.

Do I wish I'd gone with an AX15? No. I like the 6 speed ratios. And with the 4:1 low, it's a good combo for my usage.

The only issue I ever had with it was with reverse. The rebuilts all have the updated parts that eliminate the inherent reverse issue on the early specimens.

Your situation was just like mine. R is my only issue. I just saw a TJ/LJ NSG-370 pop up on FB 10 minutes ago for $900. I queried and the owner says it shifted perfectly before his LS swap. I’m so reticent to try it bc of the R issue. seems it will just happen again. I’m leaning toward rebuilt for $2K+. Thank you for sharing your experience. I also like the ratios with my 4:1, and a swap to an auto seems beyond my reach/skill.

 

[g.hayduke]

I think some TJ NSG370s got the good parts but mine is a 2005 and definitely came with the defective reverse.

Any used NSG370 is probably a gamble at best.

 

[g.hayduke]

And if anybody cares, I've been running Valvoline Synchromesh per warranty requirements. I'm going to try Redline MTL next change and see if I notice any difference.

 

[TRevs]

Time to update this thread, as more of us with NSG370’s start to have problems. Mine is really not bad yet; hopefully I can get another year or so out of it, but I have to start thinking about it.

The AX-15 swap seems reasonable, but reading @freedom_in_4low ‘s thread is a bit intimidating. I came across this thread and am hoping @g.hayduke can give us another update on the High Impact rebuilt NSG.

I’d be happy with either transmission, and they’re about the same price. But an NSG bolt-on would save a lot of time. I could use the same shifter, boot, crank sensor etc.

 

[g.hayduke]

Mine is still fine. The first/reverse issues were a design flaw that was fixed in late specimens and all rebuilts.

I don't love the way it shifts but I have no problems finding gears. I do like the ratios.

Swapping in a rebuilt is definitely the cheapest, easiest, quickest way to solve the actual problems with the NSG370. It won't make it shift like an S2000 or anything similar but works well enough for me.

I think I have about 30k miles on it since swapping it in. Works the same now as when fresh.

I do advise not putting any pressure on the shifter when not actually shifting. I believe the helps the shift fork's longevity.