NV 4500 Threads/Help

[rhsautoshop]

Our shop build is going with an NV4500 in the 66 bronco to replace the 3 speed. Is there a detailed build thread for this? If not can anyone tell me a list of what we will need to consider.

Also I see that we can get just the adapter kits or I see this at Toms Bronco Parts

https://www.tomsbroncoparts.com/product/nv4500-5-spd-transmission-adapter-kit-66-77-early-ford-bronco

Does $3150 seem right or high? I favor a one stop shop just because it will simplify things for our customer and for us. Meaning a faster build time.

Also the 3550 is less expensive bay $500 would you consider the 3550 as comparable to the 4500?

The goal is a fun mountain driver, for hunting and fishing and around the ranch. Maybe light wheeling in Moab and some mountain trails. We are going with a slightly build 302, fuel injection and a lift with 33s or 35s.

Will be need a different cross member or can the old one work if relocated?

Thanks bunch. Any other sources for the 4500 and adapters? I know Advanced makes adapters, and does wild horse, but they all seem the same...

 

[thegreatjustino]

When the NV4500 kit came out nearly 20 years ago, it was around $3,500 for the kit with a brand new transmission from New Venture. Since new transmissions are no longer available, the only option is a rebuilt unit which drops the price accordingly. Depending on your tire size, the overdrive gear may require you to re-gear the differentials.

The 3550 is a light duty Jeep transmission. The 4500 is a heavy duty truck transmission. The choice is generally based on the end use of the Bronco. Street driven only, the 3550 would be fine. It's also a sporty shifting transmission that's a lot of fun to drive. The 4500 shifts like a heavy truck transmission but will stand up to the rigors of off road use.

From your description, the 4500 would be my choice with 4.56 or higher gears in the differentials.

The conversion kit you linked to will come with the correct cross member for the conversion.

The adapters are all made by Advanced Adapters. Toms, Wildhorses, etc. all sell the AA parts.

 

[thegreatjustino]

You can download a pdf copy of installation instructions from Wildhorses website:

https://www.wildhorses4x4.com/category/Bronco_NV4500_5-speed_transmission

 

[Broncobowsher]

Didn't realize anyone was even looking at 4500 conversions these days. Thought everyone was just going for the ZF these days. Less adaptors and 5th gear doesn't fall off. Clutch is off the shelf parts (no mixing this disk with that pressure plate, and what throwout bearings works? Pilot bearing is off the shelf and not custom as well).

 

[sykanr0ng]

/\/\ +1 on the ZF5 over the NV4500
But for as light duty uses as you are building it for the M5OD might be an even better choice.
The NV3550 isn't bad, but the M5OD is easier, cheaper and very available.

If you are not building a hardcore off-road machine no need for a crawler grade transmission, especially one that drives like a heavy truck where you will be driving it the most.

 

[01JLH]

Rockland Standard Gear sells a trans they call “the Terminator”. It is basically a souped up AX15 that is supposed to handle 450lbs of torque. I have one and it is very good. You can get it with a little lower first gear as well. Talk to George there and he can fix you up. You will need to get the adapters from Advanced Adapters for a AX 15 but it really is a nice trans that works great on road, has enough strength to handle most anything you throw at it and looks like a factory installation when finished. Also, if you already have appropriate driveshafts you wont need new ones. The NV3550 and AX15 are referred to as medium duty transmissions.

 

[Apogee]

I have been driving an NV4500 for the better part of 20 years in my '77 F150...probably going to put it in my EB at some point. That said, for what you've described, the NV3550 or AX15 would probably be a funner transmission to drive and plenty strong. Otherwise, the ZF or M5OD would be both easier to swap and less expensive.

 

[DirtDonk]

Everybody that's done one of the larger transmissions (4500 and ZF) should mention what they had to do to get it to fit. Whether adding a body lift, cutting the tunnel for clearance, or both.
Seems the ZF needs a little more work in that department than the 4500, but they both need at least some sort of compensation in the tunnel area.

What all did you guys have to do to get them to fit cleanly?

Paul

 

[tacobronco]

I installed a NV4500 in my 67 with no body lift about a decade ago. Some said I'd have clearance problems without a body lift, but I used the tunnel cover from Tom's, and it worked great - full coverage of the tunnel and no clearance issues.

One thing to be aware of with both the NV4500 and ZF is that these are WIDE ratio boxes. You end up with a granny low first, gears 2-4 are about the same as 1-3 on the stock 3-speed, and a deep overdrive 5th. They also have long-throw (slow) shifting action. This is why people are rightly recommending the NV3550 for a more street-oriented or light-duty rig. That said, I've been very happy with the NV4500 in my application, which is more trail-oriented, but still with some highway driving. Some complain that the deep overdrive is useless, but I took advantage of it by going to steeper axle gears than I would have otherwise, 5.13's with only 35 inch tires. This gives me 2-5 as usable gears on the street, and I can grab 1st while still in high range for a mild obstacle.

As for the 5th gear issue, I researched this heavily because I had originally planned to do the ZF, but ran across a new NV4500 for a song. I ended up concluding it was more of an issue with high-torque, low RPM resonance in modified diesels. Then, when I got my trans, I noticed that the 5th gear nut had a HEAVY stake on it. Maybe NV updated the design? At any rate, I can't imagine that thing loosening, certainly not with my little stock 5.0 EFI motor.

In the end, for a dual-use rig that leans toward trail use, this ended up being my second-favorite mod, right after the EFI conversion.

 

[Apogee]

...As for the 5th gear issue, I researched this heavily because I had originally planned to do the ZF, but ran across a new NV4500 for a song. I ended up concluding it was more of an issue with high-torque, low RPM resonance in modified diesels. Then, when I got my trans, I noticed that the 5th gear nut had a HEAVY stake on it...

As you pointed out, the 5th gear issue at this point is pretty much moot, as I haven't seen any NV4500, new or used, that hasn't had at least one of the fixes applied. There are actually new mainshafts available now that address the issue as well by extending the splines all the way through 5th gear, along with an updated nut design. I may go this route, as I need a new mainshaft now that I'm no longer going to be running a spud adapter between my NV4500 an NP205 as I have an ATLAS that it can mate with directly.

https://nv4500transmission.com/nv4500-upgrades

 

[73azbronco]

NV4500 5th gear and nut issue are for tannies used on the Dodge diesel trucks and most had well over 100,000 miles before the issues developed. Most likely any newer NV already has the mod to stop this issue.

That said, for stock 351 and mild 302's, you really can't go wrong with a 3550.

I'm using the 4500 cause well, my motor is slightly improved........