NV4500 5 speed

[19654x4]

Has anyone installed a NV4500 5 speed into a 4x4 truck?? Any transfer case ideas? Divorced NP205 seems to be the way to go. Any other ideas. Thoughts?

[FORDification]

I saved the following from a 4wheeloffroad.com tech page that is no longer online:

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As is the case with many vehicle mods, the information and parts availability for Ford swapping are somewhat limited compared to other makes, especially with all but two of the trannies we’ve focused on for this article. Although none of the Chevy automatics can be adapted to Ford transfer cases, it should be noted that Advance manufactures a replica of factory adapter kits to mate a C4 or C6 tranny to the Bronco Dana 20 transfer case. Both of these trannies are stout in stock form and can be upgraded with a variety of aftermarket parts. In addition, Advance offers adapters for the World Class T-5 manual and AOD automatic to Bronco 20 transfer cases.

There is some good news for owners of full-size Fords equipped with married transmissions and transfer cases. Most of the transfer cases were equipped with 31-spline input gears and shared the same mounting flange bolt pattern (including the NP205 and NP208 and the Borg-Warner transfer cases). This means that in many cases, swapping the transmission simply requires unbolting the old tranny and bolting in the new one, provided the bellhousing bolt patterns and clutch linkage are the same.

NV4500

Adapting an NV4500 to a Ford engine is surprisingly easy. A Dodge NV4500 is required along with a Ford bellhousing that has a 6-1/2-inch depth and a 4.848-inch index diameter (most common Ford three- and four-speeds use this bellhousing). A simple plate connects the bellhousing to the Dodge tranny case. The OE clutch linkage can be altered to work in most situations, however the bellhousing adapter is not compatible with the internal hydraulic clutch assembly used in some full-size trucks.

When adapting a Dana 20 transfer case to an NV4500, it’s necessary to use a two-piece tailhousing for the tranny that utilizes a spud shaft to mate the Dodge tranny to the Bronco transfer case. This adapter also has provisions for a seal to isolate the tranny fluid from the transfer case. The assembled length including the bellhousing adapter is 19-1/4 inches, about 1 inch longer than the original three-speed, so driveline modifications may be necessary. Advance offers a special transmission support mount but warns that major crossmember modifications will be needed. A new clutch disc will also be needed, and you’re on your own for making the transfer case shifter linkage work.

For the full-size trucks, Advance has a kit for both the standard-duty and heavy-duty Dodge trannies. The difference lies in the output shaft spline count (23-spline on the standard-duty and 29-spline on the heavy-duty), and the heavy-duty version has the obvious advantage of greater beef. Both types use the original Dodge tailhousing combined with an adapter to mate with NP205 and NP208 transfer cases or any transfer case with a 31-spline input and a circular bolt pattern. The swap requires shortening the output shaft of the tranny and using a spud shaft to mate with the female 31-spline input of the transfer case. Driveline mods are necessary in most cases, and a transmission support bracket is available to work with a modified original crossmember.

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[averagef250]

Had one in my '70 behind a 390 for awhile. It was expensive and actually took a good bit of work to get a crossmember made and t-case shift linkage hooked up.

All in all the NV4500 gained me maybe 1-2 MPG over the 435 it replaced and I liked the 435 better. The NV4500 feels a little girly to me in an old truck, especially when you're used to shifting a 435 for a couple hundred thousand miles.

If you have your heart set on it do not go divorced. The dodge 2wd NV4500 is too long for divorced, but you can swap on a chevy 2wd mainshaft and tailhousing $$$$ like I did to get a fixed 1350 yoke and about 4 more inches of driveline.

What I've done since then for other swaps is utilize a dodge 4x4 transmission and buy a new dodge NV4500 2wd mainshaft. I have Kieth at Dutchman motorsports cut down and respline to the 2wd mainshaft for the proper Ford stickout and Ford 31 spline. Once you do this you can bolt any ford fullsize t-case right up, no adapters.

The resplining is under $100 if you don't have them re-heat treat the mainshaft. It gets spendy with heat treating and I only have them re-heat treat for high HP diesel applications. You won't strip those splines with average big block power.

If you have a six, small block or 429/460 go with the Ford ZF 5 speed.

[robroy]

Hi Dustin!

When you installed your NV4500, did you need to make a custom crossmember because of the 4x4 nature of your application, or would have have had to do that even if it were a 2WD truck?

Also, did you need to use a different clutch than what your truck came with from the factory? Or was there some kind of adapter for that?

One more question: could you elaborate on how the NV4500 felt "girly?" Does that mean the shift action felt too light?

Thanks very much Dustin!
-Robroy

[averagef250]

The NV4500 will mate to an FE in a roundabout way if you use the dodge gas V8 version. You have to use a chevy or dodge clutch disc inside a ford pressure plate with a custom pilot bushing.

2wd or 4x4 you will need to make a new crossmember and your driveline will be different.

The NV4500 shifts with minimal effort compared to a 435 or T-18/19. For me, the NV4500 behind a truck 390 (4500 RPM brute torque) the NV4500 felt wrong. I found it very interesting how even with all the torque that engine made it did not like to cruise in overdrive. The engine was far happier to cruise at 2800 RPM than 2100 at 70 MPH. I chocked it up to the downfall of a carbed engine not being able to develop the low end torque modern EFI engine's can. All in all I enjoy shifting a stiff old 435 better than an NV4500 in an old truck.

The NV4500 has very similiar ratios to the granny four speeds with an added very steep .73 overdrive.

For a performance application I would want a transmission with closer ratios than the NV4500 offers.