Nv4500 swap

[Concrete]

Hello, I’m looking for insight on swapping to a 5speed. The ax15looks to be the simple solution. The crate motor I’m gonna be dropping in is over 400 hp. So the nv4500 seems to be the better of the two. No rock crawling just some minor off roading driver. Looking for insight. Thx

 

[Drucifer]

I’ve got a NV4500 in mine. Swap is pretty easy with the advanced adapters kit. You’ll want at least a 1” body lift to make it simple.

If I were doing it today, I’d go for the TR4050 instead. Roughly the same specs but lighter and still being produced. Parts for the NV4500 are becoming harder to come by.

 

[Timmy390]

I would look at a ZF if your worried about handling HP and torque.

I went M5ODR2 because it shifts better than the HD ZF. Couldn't be happier.

Tim

 

[Broncobowsher]

Nobody does the NV4500 anymore. That was a swap from the 90s. Decent transmission, but nothing I would call great. Once the ZF adaptor came out and you could get a transmision that just bolts up to the engine with all factory parts and the only adaptor was to the transfer case, that is what people run these days.

Keep in mind that the ZF and the NV4500 are big truck transmissions. Gear spacing is very much like the old 3-speed but with a granny low and an overdrive.

For what you are describing your needs, the Mazda transmission sounds like a better choice. While still a truck transmission, they drive more like a car. A variant was used in the Thunderbird Supercoupe as it could take the torque where a T5 could not. The transmissions are quite strong. The weakness is a few rubber plugs on the shifter that age and fall out. This lets the gear oil splash out and the transmission run dry. The normal fix is to replace the rubber plugs with metal ones. Problem prevented.

 

[okorangebrnco]

If you want to cruise around and some off road action, I would consider the newer options available. I swapped to an NV4500 in 2003-2005 timeframe and it has been great, but it drives like a truck! You can take off in 2nd and 2/4 skip shift in most cases.

 

[lars]

Adding to the chorus, I've had an NV4500 in mine for 17 years. Rebuilt it myself back when OEM parts were still available. Those have long since dried up. And as the others described, it's a truck transmission and shifts as such. It can definitely take the torque; mine is behind a 408.

If I was doing a transmission swap now, it wouldn't be an NV4500, even if I were planning on rock crawling (I'm over that). I'd probably go with the Mazda transmission and enjoy the fact that it bolts right up, and the easier shifting. But I won't be swapping in a manual anymore; I'd find a nice lightly used 6R80 auto, a topic for another thread.

 

[jamesroney]

Nobody does the NV4500 anymore. That was a swap from the 90s. Decent transmission, but nothing I would call great. Once the ZF adaptor came out and you could get a transmision that just bolts up to the engine with all factory parts and the only adaptor was to the transfer case, that is what people run these days.

Keep in mind that the ZF and the NV4500 are big truck transmissions. Gear spacing is very much like the old 3-speed but with a granny low and an overdrive.

For what you are describing your needs, the Mazda transmission sounds like a better choice. While still a truck transmission, they drive more like a car. A variant was used in the Thunderbird Supercoupe as it could take the torque where a T5 could not. The transmissions are quite strong. The weakness is a few rubber plugs on the shifter that age and fall out. This lets the gear oil splash out and the transmission run dry. The normal fix is to replace the rubber plugs with metal ones. Problem prevented.

hi @Concrete ...Nobody except me out here in CA. I'm building another trail truck, and it is getting another NV4500. In an early Bronco, it is an excellent transmission. The only problem with the NV4500 is that it was offered as the OEM solution behind the Cummins starting in 94. High torque at low rpm in 5th gear pulling 20,000 lbs was a problem. It got a bad reputation for 5th gear falling off, well...because 5th gear fell off.

But nobody ever complained about 5th gear in the GM version, or any 2WD version, or any version that got the upgraded 5th gear nut. Fast forward 20 years, and the only problem with the NV4500 is that the input shaft gear is too small (it's bigger than the ZF version...) and twists off behind 700HP diesels.

It also got a bad reputation because people run the wrong gear oil in it. Anything other than Castrol Syntorq, GM 12346190 , and maybe Redline MTF causes the carbon fiber glue to de-bond from the synchro balk ring. Replacing all synchros with bronze takes care of that.

The ZF is a decent transmission, and since no one puts any torque into them...they hold up pretty good. At the end of the day, the center-distance and gear ratio defines the torque capacity of the transmission. You will not break a NV4500 behind a small block ford. @nvrstuk tells you that he ran a NV4500 for 17 years. Take a look at all of the other stuff that he has destroyed...and that's quite a testamony. Yeah, he likes the 6R80 now. I'm sure it will get him to the grocery store.

If I were building an Early Bronco, (and I am...) It would get an NV4500.

 

[jamesroney]

Hello, I’m looking for insight on swapping to a 5speed. The ax15looks to be the simple solution. The crate motor I’m gonna be dropping in is over 400 hp. So the nv4500 seems to be the better of the two. No rock crawling just some minor off roading driver. Looking for insight. Thx

Oh, I forgot to do my rant on the AX15.

The AX15 has exactly the opposite problem as the NV4500. The NV has been put behind everything imaginable, and beaten to death. The AX15 has never been put behind anything powerful, and has rarely been abused to failure. Thus resulting in undeserved accolades. The AX 15 was used behind the AMC 4.2 and 4.0 in the 1/4 ton Jeep from 87-00. Pathetic engine in front of a lightweight car developing no torque. Resulted in a lot of blown up Dana 35 rear axles. But the trans held up pretty well. Also used behind a fair number of Toyotas as the R151, or the Supra Turbo as the R154. So lots of RPM, light weight, and a well earned reputation. Gears hold up pretty well, and aside from a bunch of broken bell housings, and aluminum cases...not too many complaints. I've heard rumors of R151's getting into the 10's at the track at 500+ RWHP. But Horsepower doesn't break transmissions. Torque breaks transmissions.

There are plenty of blown up R154's. 3rd gear is the one that gets stripped. There's a pic here.

I'm not saying that it's a bad transmission. It just isn't as strong as a Nv4500. And when you start to abuse it, it will fail. You will not break your NV4500 in any gear except 5th.

Now wait to hear about all of those grocery getters that "never had a problem.." and "anything will break if you abuse it..." or "you shouldn't be using it that way..." The same logic is the reason why the Dana 30 has been used (unsuccessfully) since 1966 and still leaving unsuspecting Jeepers broken on the trail.

 

[nvrstuk]

... well, if someone is going to say some thing about how I drive, what I drive and that what I drive ought to get me to the grocery store.... at LEAST quote me as driving with the right tranmission! lol

Quoted from above "...nvrstuk tells you that he ran a NV4500 for 17 years. Take a look at all of the other stuff that he has destroyed...and that's quite a testamony. Yeah, he likes the 6R80 now. I'm sure it will get him to the grocery store."


Correction: I actually ran a ZF with doubler (years before there were any kits for ZF's with doublers) from '99 till 2011 when I put in a 4r70W with a doubler, then in 2019 the 6r80.

This pic below was taken when I took the wrong turn on the way to the grocery store. Gotta start paying more attention.

 

[Timmy390]

When you get up in the 400HP range, the trans is NOT the weak link IMO.......Other things tend to let go......Did the below with stock 3 speed going into second.......

With the Bronco being so light.....ZF or M5ODR2 will be fine.........

Tim

 

[jamesroney]

... well, if someone is going to say some thing about how I drive, what I drive and that what I drive ought to get me to the grocery store.... at LEAST quote me as driving with the right tranmission! lol

Quoted from above "...nvrstuk tells you that he ran a NV4500 for 17 years. Take a look at all of the other stuff that he has destroyed...and that's quite a testamony. Yeah, he likes the 6R80 now. I'm sure it will get him to the grocery store."


Correction: I actually ran a ZF with doubler (years before there were any kits for ZF's with doublers) from '99 till 2011 when I put in a 4r70W with a doubler, then in 2019 the 6r80.

This pic below was taken when I took the wrong turn on the way to the grocery store. Gotta start paying more attention.

I am so sorry, and I do apologize. For some reason, I thought of you when I read @lars post. I will pay more attention in the future.

 

[nvrstuk]

We're good James!! I wasn't offended in the least, zip.

I do seem to be a "parts toughness tester" for some reason! Could be the tens of thousands of miles and many of them are tough on parts-even to the grocery store!!

I actually twisted the 35 spline ARB case in half on the way home from the grocery store. 6 grand shift into 2nd might have had something to do with it. Kind of a mess.

 

[lars]

I am so sorry, and I do apologize. For some reason, I thought of you when I read @lars post. I will pay more attention in the future.

James, confession... my reply above was, well, ahem... baiting a bit. I figured you'd take it, and my apologies, you did, and once again I learned a few (lot of) things. I'm no transmission expert, my NV works fine and I also learned a few things from rebuilding it oh so long ago (with those spendy carbon fiber synchronizers, as they were still available).

I am sorta slowly getting to trust my latest engine, not an easy thing as I'm a nervous nellie on a good day, but eventually I"d like to get together your way. Maybe round up a few of the other NorCal Bronco owner locals as well.

 

[jamesroney]

James, confession... my reply above was, well, ahem... baiting a bit. I figured you'd take it, and my apologies, you did, and once again I learned a few (lot of) things. I'm no transmission expert, my NV works fine and I also learned a few things from rebuilding it oh so long ago (with those spendy carbon fiber synchronizers, as they were still available).

I am sorta slowly getting to trust my latest engine, not an easy thing as I'm a nervous nellie on a good day, but eventually I"d like to get together your way. Maybe round up a few of the other NorCal Bronco owner locals as well.

No problem, evidently I like bait. (Hook, line & sinker…)
And a NorCal broncos reunion is way past due. Maybe we can get someone to set it up.

 

[Concrete]

Nobody does the NV4500 anymore. That was a swap from the 90s. Decent transmission, but nothing I would call great. Once the ZF adaptor came out and you could get a transmision that just bolts up to the engine with all factory parts and the only adaptor was to the transfer case, that is what people run these days.

Keep in mind that the ZF and the NV4500 are big truck transmissions. Gear spacing is very much like the old 3-speed but with a granny low and an overdrive.

For what you are describing your needs, the Mazda transmission sounds like a better choice. While still a truck transmission, they drive more like a car. A variant was used in the Thunderbird Supercoupe as it could take the torque where a T5 could not. The transmissions are quite strong. The weakness is a few rubber plugs on the shifter that age and fall out. This lets the gear oil splash out and the transmission run dry. The normal fix is to replace the rubber plugs with metal ones. Problem prevented.

What trans is the Mazda trans your speaking of? I’m learning as I go lol. I finished my 1st bronco build. Starting my second. I’m hooked lol.

 

[Broncobowsher]

M5R2 From F150. They were used behind small blocks in the 90's. But the '97 to mid '00s 4.2 V6 has a better shifter location and the same small block bolt pattern and is a better fit. You just have to find one that was ordered as a 4x4 and the V6, the 2WD transmission won't work.

 

[Timmy390]

Good info if I do say so myself

https://classicbroncos.com/forums/threads/m5odr2-conversion-complete.314563/

Tim

 

[Bajabrewer]

M5R2 From F150. They were used behind small blocks in the 90's. But the '97 to mid '00s 4.2 V6 has a better shifter location and the same small block bolt pattern and is a better fit. You just have to find one that was ordered as a 4x4 and the V6, the 2WD transmission won't work.

More info on the M5R2 - also called the M5OD-R2

https://www.f150hub.com/trans/m5od-r2.html

I'm in the middle of doing this swap now. You can take the V6(rear position) top plate/shifter from a 2wd version & with a little grinding on the shift rails replace the center position top plate/shifter on a 4wd one.
1st pic is the center shifter next pic is the rear position one.

 

[DirtDonk]

Did someone just say “Bronco party at James’ house“ by any chance?

Then again, if the groaning sound we hear is James’ wife rolling her eyes, there’s always a big parking lot to hang out in over at the GF’s Mongolian restaurant in Menlo Park.
It is a bit further way out west here, but just a little extra skip and a jump over the 84 bridge and you’re there.

 

[sprdv1]

Hello, I’m looking for insight on swapping to a 5speed. The ax15looks to be the simple solution. The crate motor I’m gonna be dropping in is over 400 hp. So the nv4500 seems to be the better of the two. No rock crawling just some minor off roading driver. Looking for insight. Thx

We want pics when done or the swap