Scout II BUILD with Rockwells, Cummins 12V, and 46" Claws

[Blak Falken]

A couple more:

[Blak Falken]

Here is the front Rockwell after modification, rebuild, and reassembly:

[Blak Falken]

While I had been working on the steering and brakes for the front axle, I was also working designing the spring hangers for the front.

I wanted to run a reverse shackle setup. As previously mentioned I bought some Chevy 56" leaf springs for the front, these springs use a 4.00" offset center-pin. I choose these springs so I could get a long spring in the front while keeping my approach angle decent. It proved to be a little difficult designing the front hangers to get an equal amount of lift as the rear spring hangers while using a reverse shackle configuration.

With some simple Trigonometry I figured out some critical dimensions and sketched out the design. Next I turned to Solidworks and started modeling the spring hangers. Once the design was done I had them laser cut, Tony welded them up, and I tacked them in position. At this point I still had the IH drivetrain in the Scout to set the angle on my shackles. Since the new drivetrain with the Cummins would be a little heavier I figured the springs would compress more and the angle would increase when the Cummins goes in.

This was the sad day I dropped out the IH drivetrain (IH 304, 727TF, Dana 20) after getting my spring hangers positioned:

[1966Scout800]

Axle looks clean, good writeup and thread. But why not the 304?

[Blak Falken]

Originally Posted by 1966Scout800

Axle looks clean, good writeup and thread. But why not the 304?

Thanks. Sarcasam aside...I was pretty dead set on keeping the IH drivetrain for a little while until I started looking at different transfercase options, this meant a different tranny...which ultimately meant a different powerplant especially when I started looking at EFI or MPFI conversions. I decided my money would be better spent doing a Cummins swap i.e. lots of torque, no issues with carburetion, improved efficiency, more readily available parts, etc.

[Blak Falken]

On the axle I figured out that the leaf springs would sit at roughly 12 degrees below the horizontal, this meant way to much of an angle on the axle. So I set the perches on the axle in the same orientation with around 7 degrees below the horizontal, thus netting around 5 degrees on the Rockwell axle housing giving some caster at the kingpins.

Here is how I set the perches in:

[Blak Falken]

The shackles were cut from 0.500" steel plate, the spring hangers were cut from 0.250" steel plate, and cross braced in the front with 0.250" wall DOM.

Once everything was fit-up and tacked in position, Tony burned them in:

[Blak Falken]

Next on the list was the motor mounts and frame plates.

Here are a couple pictures of the Cummins 12V when I got it, and after pulling off some of the stuff that I didn't need:

[Blak Falken]

Here is the adapter I bought to mate the Th475 up to the Cummins . If you look closely at the adapter you will notice that it tilts the Cummins in relation to the transmission, this angle of tilt is 10 degrees. This is the same adapter that Cummins used to mate 4BT's up GM trannies in "bread-van" applications.

[Blak Falken]

With the Cummins and the adapter at my disposal I started pulling a lot of dimensions off the 6BT and considering different options for the motor mounts. I decided to use polyurethane bushings for the motor mounts, but I also wanted a cross-member to rigidly connect the two frame rails to eachother so they wouldn't be twisted with the torque of the Cummins. I also wanted the cross-member to be a bolt in unit so if I ever needed to remove the oil pan from the Cummins I could have access.

So after some initial concept sketches I started designing in Solidworks, here is a rough animation of what I came up with:

International Scout II to Cummins 4BT/6BT Motor Mounts for tilted GM Tranny Adapter - YouTube

[Blak Falken]

Here are the motor mounts after being laser cut (there are a few other misc. tabs in the picture that aren't part of the mounts):

[Blak Falken]

Here are the motor mounts after fit-up and welding.

[Blak Falken]

As I was working on the motor mounts, I started pulling dimensions off the front of the frame and putting them into Solidworks. Just as I had plated select portions of the rear frame with 10 gauge steel plate I started designing the frame plates for the front. For the front I decided to plate both horizontal planes and both vertical planes of each frame rail due to the torque of the Cummins and the extra drivetrain weight, I wanted to minimize the possibility of a frame related failure.

Here are the frame plates for the front after being laser cut:

[keeptahoewhite]

Originally Posted by Blak Falken

Here are the frame plates for the front after being laser cut:

[Blak Falken]

Taking a little detour...

I wanted to add a little more of a custom touch to the Rockwells. In keeping with the spider web and Iron Cross theme I designed these flanges to bolt onto the pinion flanges on the Rockwells opposite the driveshafts, one per axle.

Here is a Solidworks animation:

2.5 Ton Rockwell Axle Ripper - YouTube

[Blak Falken]

Here they are after being laser cut, I bolted one to the front axle to see how it looked...I was pretty happy with how they came out. I was thinking of countersinking the bolt holes but I threw some SHCS in there, I think they look pretty good.

What do you guys think?

['71 800B]

[Buck Dodson]

Originally Posted by Blak Falken

Here they are after being laser cut, I bolted one to the front axle to see how it looked...I was pretty happy with how they came out. I was thinking of countersinking the bolt holes but I threw some SHCS in there, I think they look pretty good.

What do you guys think?

Nice work, but that thing spins, right?

[keeptahoewhite]

No synthetic winch rope for you...

[Blak Falken]

Before I could start plating the frame I had to take care of a problem with the motor mounts. The frames on a Scout II have a section that is necked down on both of the vertical planes of each frame rail, four spots in total...this is where my motor mounts needed to go for the Cummins swap.

You'll notice the problem I was referring to in these pics:

[Blak Falken]

Here is how I took care of it. I made a planar surface for the mounts to be welded in to by cutting some filler plates out of 0.250" steel and welding them in.

Pictured is one pass on the filler plate with the welder, and after it was sanded smooth for a seamless non-necked down frame. I welded these plates into all four necked down sections and sanded them smooth.

[Blak Falken]

Next I started cleaning the rust and build-up off the frame and fitting up the fish plates. Once that was done I coated the frame and inside of the fish plates with weld through primer and burned them in

Here are some pics of the process:

[Blak Falken]

My angle was slightly off on the the fish plates that mount to the vertical planes of the frame so I cut the plates at the transition, tweaked the angle slightly and burned them in.

[Blak Falken]

A couple more:

[Blak Falken]

A few more: