The elusive NP205 6x6 transfer case

[Will Scarlet]

http://localhost:8080/conversions/usa-6x6.html

You can contact us by email: [email protected]

The link you had with localhost:8080 wil try to connect to port 8080 on the local computer, so here's the correction for the link you provided:

USA 6x6

During the years USA 6x6 was in business, it did build 6x6 conversions of various vehicles

6-wheel-drive.org

 

[M92PV4U]

The link you had with localhost:8080 wil try to connect to port 8080 on the local computer, so here's the correction for the link you provided:

USA 6x6

During the years USA 6x6 was in business, it did build 6x6 conversions of various vehicles

6-wheel-drive.org

Weird, I was on the website and copied the link.

 

[PAToyota]

No. Because if you're hauling enough weight in a light truck to require 3 axles it's cheaper, quicker and easier to go with a medium/heavy duty truck that already was engineered, designed and built with three axles.

The army in WWII figured this out with the Dodge WC62/63 6X6.

They're pretty popular over in Australia to have more capacity on a smaller vehicle that will fit through their backcountry trails. The Land Cruiser 70 Series is a popular platform for them. Most seem to use a custom pass-through (or through-pinion) Land Cruiser axle for the middle axle.

Please share the context of this contraption

A "gearover box" - a series of gears to permit pass-through to the one differential and also "up and over" to a driveshaft to the rearmost axle.

The infamous USA6x6 was doing that back a couple decades ago...

Another option is Differential Engineering Inc. that makes pass-through (or through-pinion) Ford 9" axles: Differential Engineering

They do the axles for the Hennessey VelociRaptor 6x6:

And the Hennessey Mammoth 6x6:

 

[PAToyota]

As well as options all those Jeeps everyone keeps doing:

 

[shortbus4x4]

I would love me a Landrover Perentie 6x6 from down under.

 

[total newb]

Well shit. I guess i have to find that goofy fuck dana setup pic again.

 

[gozuki]

Now, that's some sexy engineering. I'd love to look at the thirds

 

[shortbus4x4]

Now, that's some sexy engineering. I'd love to look at the thirds

Whoa, there buckaroo. Nobody peeps at the sexy thirds without putting some money on the barrel head first.

 

[PAE]

Whoa what are you now a pimp ?

Whoa, there buckaroo. Nobody peeps at the sexy thirds without putting some money on the barrel head first.

 

[shortbus4x4]

Whoa what are you now a pimp ?

Depends on who's asking?

 

[PAToyota]

 

[total newb]

That answers one question but i now have more.

 

[Penetrode Offroad]

Thanks for stepping up with the pic I shared. It was a random FB post.

 

[PAToyota]

That answers one question but i now have more.

Such as?

 

[total newb]

* as i was typing i understood something so i got it now.

Dont ever swap the 3rd out for a different one. The housing and 3rd are line bored so the pinion is sqr'd. I couldnt wrap my head around how the pinion would be sqr if you had to adjust things, but i get it now.

 

[arse_sidewards]

* as i was typing i understood something so i got it now.

Dont ever swap the 3rd out for a different one. The housing and 3rd are line bored so the pinion is sqr'd. I couldnt wrap my head around how the pinion would be sqr if you had to adjust things, but i get it now.

Is that from the manufacturer or just your take on it?

Because it sounds dumb and there's better ways to do that but I guess when you're trying to shave cents so you can line your pockets with the difference I guess it makes sense for low volume shit.

 

[highway101]

I have ideas for doing this as well using NP203 differential parts and two GM 14 bolt axles. The front one would be flipped over to drive from the rear and an input shaft would come through the back cover to the NP203 differential similar to a championship quick change rear end. I will start a new thread when the time comes to design all that.

 

[highway101]

I have been refining the design of the counter shaft setup. When I use the NP203 main shaft for the counter shaft I ran into the problem of the rear thrust bearing having less than 1/16" on the edge. The way to fix this problem is to turn down the front end of the shaft to fit the NP205 case and then bore the shaft out to 7/8". Either turn down the NP205 shaft or use a 7/8" bolt to hold it in place. By doing this the counter gear sleeve with all of its gears and shift collar will be installed with the front thrust washer. The shaft will go through and seat against the front thrust area. The rear thrust washer will be installed and then the through bolt will be installed and tightened against the rear thrust and the shaft.

 

[highway101]

More measurements and another slight revision. The NP203 mainshaft is only slightly smaller than the larger part of the NP205 countershaft pin. The problem with that is the floating thrust washer has less than 1/16" of support.

New design is turning down the front of the NP203 transfer to match the NP205 countershaft pin. The back part will be machined off with a step and threads inside the rear of the shaft. The rear end of the NP203 shaft will be short of reaching the rear of the case. A thrust washer will be slipped in and then a rear piece will be threaded into the shaft that fits the thrust washer and the back hole of the case.

Assembly will be put the NP205 case on its front face on 4x4 blocks. Install the front thrust bearing. Install the assembled counter shaft with its needle bearings and spacers inside. Carefully slide the counter shaft pin through and install washer and nut. Slide rear thrust bearing and thrust washer in. Install rear plug and tightened it down to center and sandwich the thrust washer.

 

[highway101]

I just picked up an NP202 to look at how they did the counter shaft. It was pretty full of water but I think I can get it apart and still figure it out. I mainly am interested in the counter shaft parts but am also thinking about documentation of difference and interchangeability of the parts in the NP200, NP201, NP202, and NP205 as they are in the same family. I'm not totally sure but I think that some NP203 parts are interchangeable with the NP205.

 

[Winchested]

Matt's offroad is building that med duty truck using two np205s I believe second one set up as a splitter box for two outputs to two dana 80s with a carrier bearing on the first axle for the rear axle.

 

[highway101]

Matt's offroad is building that med duty truck using two np205s I believe second one set up as a splitter box for two outputs to two dana 80s with a carrier bearing on the first axle for the rear axle.

That is one way to do it if you don't care about weight. With the set-up that I want to build, it will all be in one NP205 case. The other thing that it will have is a differential between the two rear outputs.

 

[Winchested]

That is one way to do it if you don't care about weight. With the set-up that I want to build, it will all be in one NP205 case. The other thing that it will have is a differential between the two rear outputs.

Righto, they used ORD for their NP205 splitter and said rather than mount the carrier on the front axle they will be using a carrier off the frame. They're using two dana 80s. So no option for differential driven rear axle.

 

[highway101]

I ordered thrust bearings and washers, along with a 3" needle bearing. I also bought some shift forks and collars off ebay. Once these show up then it's time to get some machine work done. I'm probably going to work on the counter shaft assembly as it will be one of the harder parts to build.