NV3550 replacement / rebuild advice

Wombat

Wombat

TJ Enthusiast
Joined
Jul 18, 2018
Messages
333
Location
Melbourne VIC, Australia
Hi all,

Well it looks like the 4.6 with its 400 n/m has had it's way with my much loved NV3550. It's making a grinding noise if you load it up under 1,500 RPM in second and third gear, and leaking a small amount of oil from the bellhousing making the clutch shudder a little at very low revs. Strange thing, it if I drive it like I stole it the box sounds good.

I would like to rebuild it and not sure what kit or parts to buy from rockauto. How do I work out which one of these kits suites my countershaft bearings 1.30 or 1.18?

Trans. code NV3550; 0.9 inch wide input/output bearings, 1.30 inch I.D. counter shaft bearings, multi-piece 1st-2nd gear synchro rings, w/reverse synchro ring
Trans. code NV3550; 0.9 inch wide input/output bearings, 1.18 inch I.D. counter shaft bearings, multi-piece 1st-2nd gear synchro rings, w/reverse synchro ring
https://www.rockauto.com/en/catalog/jeep,2001,wrangler,4.0l+l6,1373723,transmission-manual
I would appreciate any advice as to what else might be worth replacing after 120,000+ miles of service? Keep in mind apart from the two issues mentioned above (grinding noise if you load it up under 1,500 RPM in third gear and leaking a small amount of oil from the bell housing) it is shifting just like it did when it was new.

Also, I have a near free shipping option from CA to AU so a full replacement/recondition box is also an option.
 
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Have you just considered replacing it with a brand new AX15 like @CodaMan suggested? You get a brand new one for pretty cheap, which is hard to beat.
 
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Also, figure in tools for the rebuild. The NV3550 takes some specialized fixtures to hold the main and counter shafts and reverse gear. The case kinda slides over the shafts, and you have to have reverse in position before you do so.

This is a member here. He's rebuilding the 6 speed, but the theory is similar.

 
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bromel said:
Normally I'd say replace with an AX-15, as recommended above. But the AX-15 is rated for 300 ft/lbs, right where your 4.6 is. I would consider the Rockland Terminator.

http://tcase.rsgear.com/products/transmissions/terminator™.aspx
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Agreed. They are a good bunch to work with.
 
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Thanks for all this info! - You guys ROCK!

bromel said:
Normally I'd say replace with an AX-15, as recommended above. But the AX-15 is rated for 300 ft/lbs, right where your 4.6 is. I would consider the Rockland Terminator.

http://tcase.rsgear.com/products/transmissions/terminator™.aspx
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Awesome

I called them to get a price but they are closed for a holiday? Does anyone know what the price is?

I'm not a big fan of the AX15 and the NV has a lower 1st with a taller 3rd and overdrive, IMOP it shifts smoother. Also, third gear is taller and I like that a lot - with the right gearing you only need to go back to third in most intersection provided your on flat ground and dont need to load it up - because makes for better economy and less shifting in general.

I would consider the six speed but again, this means shifting more with much the same result and after playing around with my buddies TJ six speed - is the 6 speed a direct bolt in? - I find it makes a sort of click sound/feel that I don't really like much, nevertheless I'm sort of splitting hairs here as all three boxes are pretty good, however, for me the NGV 3550 is the cream of the crop - it's never jumped out of any gear, has better ratios that suits my driving style and it's stronger.

I'm also looking at a smallish turbo in the future so I do want something that's going to deal with 350 - 400 HP. I also spoke to novak and they say the NV is a better choice for my 4.6, particular if I plan to turbo or supercharged it.
 
Wombat said:
Thanks for all this info! - You guys ROCK!


Awesome

I called them to get a price but they are closed for a holiday? Does anyone know what the price is?

I'm not a big fan of the AX15 and the NV has a lower 1st with a taller 3rd and overdrive, IMOP it shifts smoother. Also, third gear is taller and I like that a lot - with the right gearing you only need to go back to third in most intersection provided your on flat ground and dont need to load it up - because makes for better economy and less shifting in general.

I would consider the six speed but again, this means shifting more with much the same result and after playing around with my buddies TJ six speed - is the 6 speed a direct bolt in? - I find it makes a sort of click sound/feel that I don't really like much, nevertheless I'm sort of splitting hairs here as all three boxes are pretty good, however, for me the NGV 3550 is the cream of the crop - it's never jumped out of any gear, has better ratios that suits my driving style and it's stronger.

I'm also looking at a smallish turbo in the future so I do want something that's going to deal with 350 - 400 HP. I also spoke to novak and they say the NV is a better choice for my 4.6, particular if I plan to turbo or supercharged it.
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Not sure what the price is. It's probably not cheap, given the quality of the parts. Try them after the holiday.
 
Wombat said:
Thanks for all this info! - You guys ROCK!


Awesome

I called them to get a price but they are closed for a holiday? Does anyone know what the price is?

I'm not a big fan of the AX15 and the NV has a lower 1st with a taller 3rd and overdrive, IMOP it shifts smoother. Also, third gear is taller and I like that a lot - with the right gearing you only need to go back to third in most intersection provided your on flat ground and dont need to load it up - because makes for better economy and less shifting in general.

I would consider the six speed but again, this means shifting more with much the same result and after playing around with my buddies TJ six speed - is the 6 speed a direct bolt in? - I find it makes a sort of click sound/feel that I don't really like much, nevertheless I'm sort of splitting hairs here as all three boxes are pretty good, however, for me the NGV 3550 is the cream of the crop - it's never jumped out of any gear, has better ratios that suits my driving style and it's stronger.

I'm also looking at a smallish turbo in the future so I do want something that's going to deal with 350 - 400 HP. I also spoke to novak and they say the NV is a better choice for my 4.6, particular if I plan to turbo or supercharged it.
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After delivery mine was $1808 and that was in Jan 2019. I thought that I'd notice a difference based on gearing but I didn't.
 
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Rec_Rider said:
After delivery mine was $1808 and that was in Jan 2019. I thought that I'd notice a difference based on gearing but I didn't.
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$1800? Wow, that's pretty cheap considering the stock AX-15 costs only a little bit less. Are you happy with your purchase?
 
bromel said:
$1800? Wow, that's pretty cheap considering the stock AX-15 costs only a little bit less. Are you happy with your purchase?
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Extremely. I don't put a lot of miles on my Jeep but it has worked great for as long as I've had it. You will have a buy a new shifter since you can't use the one from the NV3550. I made one which saved me a little and allowed me to bend it the way I wanted.

It was night and day from what I was dealing with. Since I crawl I didn't look into an automatic but that should have been a thought. Still, I'm not questioning my decision.
 
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I called in on Wed about the Terminator and they said they do nothing internally to change the transmission at all so I am not sure its any different from the Novak option. I got a quote for the Terminator where it was $1595 for trans and about $150 for shipping.
 
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XCRN said:
I called in on Wed about the Terminator and they said they do nothing internally to change the transmission at all so I am not sure its any different from the Novak option. I got a quote for the Terminator where it was $1595 for trans and about $150 for shipping.
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Weird. That is contrary to their advertisements. Maybe they stopped producing the original Terminator and just stock AX-15s now. That’s very disappointing.
 
bromel said:
Weird. That is contrary to their advertisements. Maybe they stopped producing the original Terminator and just stock AX-15s now. That’s very disappointing.
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I have been doing a lot of research on the subject, I have seen claims for being able to take more torque but never from RSG them selves. I called into Novak and they said their offering was could maybe handle 350ft/lbs but they even said thoes are not official numbers. I do not believe anyone sells the new AX15 with officially stated numbers.

So all I can say is either option would be equal, and for me they both come in shipped at around $1750, only thing I see Novak has over RSG Terminator is the Novak comes with a shifter that allegidly needs to be bent to fit. I never asked if the Terminator came with a shifter so cant say that it does or does not come with.
 
Rec_Rider said:
$1808
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Well if it's got all the features they say it has I guess it's going to be worth it in the long run, quality is remembered long after the price is forgotten.
ejay said:
I'm trying to get a wrap around the issue here. Your stroker destroyed your NV3550?
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After 200,000 kilometers about (120 miles) I expected to have to replace the gearbox, was working fine beforehand but in my XP with building high HP cars you can bet your bottom dollar that when you replace an old motor in an old vehicle with a new one, it's going to destroy everything behind it.

It's like power travels down through the driveline components looking for old parts to have it's way with.
 
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bromel said:
Weird. That is contrary to their advertisements. Maybe they stopped producing the original Terminator and just stock AX-15s now. That’s very disappointing.
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...sheesh! why do I have to love the NV - has a higher torque rating, shifts are more fluid the the NSG or AX and the ratios are a tad better then the AX for crawling and highway driving, however...

...what are everyone's thoughts on converting to the six speed NGV? Is it a drop in plug and play or does it require modifying floor pan and other stuff?
 
Wombat said:
...what are everyone's thoughts on converting to the six speed NGV? Is it a drop in plug and play or does it require modifying floor pan and other stuff?
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Almost no one does that swap, for a good reason. The NGV is generally considered an inferior transmission, and the swap is very difficult. It involves getting a new bellhousing, flywheel, crank sensor relocation, etc. You'll see that all the swap threads are the opposite—i.e. from the NGV to the AX-15.
 
I have a 727 amc and I am looking at a cj999 transmission to install in the lj, if I can find a shifter from a 98 or so and the kick down linkage, it will be an easy install. My nsg growls so bad that I can’t trust it...and if I have to move the crank sensor, I might as well go auto without a computer or overdrive. Tim
 
bromel said:
Almost no one does that swap, for a good reason. The NGV is generally considered an inferior transmission, and the swap is very difficult. It involves getting a new bellhousing, flywheel, crank sensor relocation, etc. You'll see that all the swap threads are the opposite—i.e. from the NGV to the AX-15.
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Thanks bromel and I thought as much, I guess you could say I'm clutching at straws looking for a credible alternative or at least an affordable one.

I've always been of the opinion that the 2000 to 2004 model equipped with the NV was the most bulletprufe and capable TJ including the 2000 to 2002 having the best breakover angle as a result of the transfer skid being dropped lower after 02 to help with driveline vibrations issues that the TJ suffered during those 00-02 years.

I can still shift the tired old NV with my pinky, never jumped out of gear despite its age and condition so I love it and don't want another option if possible. I will contact Rockland on Tuesday - USA time Monday - and hopefully the below information continues to be correct and current...


The TERMINATOR Jeep XJ & TJ Trans Upgrade​

Jeep transmission upgrade for 2000-04 TJ and 2000-2001 XJ.​

Jeep owners now have an alternative to the New Venture 3550 5-speed manual transmission found in 2000-2001 XJ and 2000-2004 TJ Wrangler six cylinder models. The NV 3550 is infamous for the rattling sound it makes in neutral, grinding on the 1-2 shift and jumping out of gear on deceleration.

To make matters even worse, New Venture Gear is out of business, and the only replacement parts are inferior offshore components, or used salvaged parts. Rockland Standard Gear's new 5-speed upgrade appropriately called "The Terminator" is a direct bolt-in replacement with more torque capacity for extreme duty, and for Jeeps with engine modifications.

The Terminator uses the stock shifter (and 4WD shifter) in its original location. OEM replacement parts are guaranteed to be available for the next 10 years, and RSG carries a complete inventory of parts and transmissions. Best of all, upgrading to the Terminator is very affordable and ensures that you will only need to make this fix once.

astjp2 said:
I have a 727 amc and I am looking at a cj999 transmission to install in the lj, if I can find a shifter from a 98 or so and the kick down linkage, it will be an easy install. My nsg growls so bad that I can’t trust it...and if I have to move the crank sensor, I might as well go auto without a computer or overdrive. Tim
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Nice! but I'm not going to go back to an auto as my first new TJ had an auto and I didn't like it. I yearn for the challenge of selecting the right gear in the most challenging of situations, doesn't always come off right but when it does it's poetry in motion.
 
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