Nothing Special's '71 Bronco

[Nothing Special]

Well done! Now for the real project.

A lot of work with a little to show for it. I decided the first thing to do would be to make clearance to clock the transfer case up. The Atlas 2 transfer case has 4 sets of holes for the mounting studs. Putting the studs in different holes will rotate the 'case up or down. When I first installed the Atlas I found that it had to be clocked in the lowest position to clear the frame.

That hasn't been a huge issue with the dropped radius arm mounts because it was still higher than the arm mounts. But now that I'm going to be raising the radius arms I want to get the transfer case higher. Here's an out-of-focus side view showing the current situation. The tape measure is showing 15.5" clearance under the lowest point on the transfer case.

I started off cutting as little as I thought I could get away with, then tried fitting the transfer case in with the studs moved to the second position. I kept finding where it was hitting and gnawing off a little more metal until I could fit it in position 2. Here's the hole in the frame I ended up with...

... and here are the places where more material needs to be removed if I'm going to go any higher

I don't really want to cut much higher on the frame, and I'm a little afraid that I might need to even go through the top of the flange to get to the third position. And opening up the hole more to the front would require moving the trans cross member mounting holes which gets a little challenging. (This last picture also shows the original radius arm mounting holes above the current dropped location).

On the plus side, going up one position won't require making a new trans cross member (it would have to go below the front driveshaft rather than above if I go up another step. But on the minus side, I only gained about 1/2" under the transfer case

My original plan was to finalize where the transfer case was going to end up and then reinforce the frame where I cut it before moving on to other parts of the project. But I decided to put the transfer case on hold for now. I'm not at all sure that I want to do what it will take to go up another step, so I'll get the radius arm mounts back to stock height, get the wedges cut off the axle and rotate the pinion up to see how the front driveshaft lines up. At that point I'll see if it looks like clocking the transfer case higher will gain me enough to be worth the extra work.

[Gary Lewis]

A lot of work with a little to show for it. I decided the first thing to do would be to make clearance to clock the transfer case up. The Atlas 2 transfer case has 4 sets of holes for the mounting studs. Putting the studs in different holes will rotate the 'case up or down. When I first installed the Atlas I found that it had to be clocked in the lowest position to clear the frame.

That hasn't been a huge issue with the dropped radius arm mounts because it was still higher than the arm mounts. But now that I'm going to be raising the radius arms I want to get the transfer case higher. Here's an out-of-focus side view showing the current situation. The tape measure is showing 15.5" clearance under the lowest point on the transfer case.

I started off cutting as little as I thought I could get away with, then tried fitting the transfer case in with the studs moved to the second position. I kept finding where it was hitting and gnawing off a little more metal until I could fit it in position 2. Here's the hole in the frame I ended up with...

... and here are the places where more material needs to be removed if I'm going to go any higher

I don't really want to cut much higher on the frame, and I'm a little afraid that I might need to even go through the top of the flange to get to the third position. And opening up the hole more to the front would require moving the trans cross member mounting holes which gets a little challenging. (This last picture also shows the original radius arm mounting holes above the current dropped location).

On the plus side, going up one position won't require making a new trans cross member (it would have to go below the front driveshaft rather than above if I go up another step. But on the minus side, I only gained about 1/2" under the transfer case

My original plan was to finalize where the transfer case was going to end up and then reinforce the frame where I cut it before moving on to other parts of the project. But I decided to put the transfer case on hold for now. I'm not at all sure that I want to do what it will take to go up another step, so I'll get the radius arm mounts back to stock height, get the wedges cut off the axle and rotate the pinion up to see how the front driveshaft lines up. At that point I'll see if it looks like clocking the transfer case higher will gain me enough to be worth the extra work.

It looks like with the radius arms back in the stock position that the radius arm brackets and the Atlas will both have about the same clearance. Could you put a plate off the radius arm bracket to protect the Atlas and call it good?

And how are you going to reinforce the frame? Can you lay a piece of channel the same height as the frame on the outside and weld it on?

[Nothing Special]

It looks like with the radius arms back in the stock position that the radius arm brackets and the Atlas will both have about the same clearance. Could you put a plate off the radius arm bracket to protect the Atlas and call it good?...

I think the transfer case will be lower, but time will tell.

And I am planning on putting a skid plate under the transfer case. I don't know exactly what it will look like or where it will attach yet. That all is yet to be determined.

... And how are you going to reinforce the frame? Can you lay a piece of channel the same height as the frame on the outside and weld it on?

The plan is to re-box it by welding pieces in. I might also plate the outside of the frame. But I don't have much room for a channel there. It's wide open now, but that's where the aux fuel tank lives. I pulled that out for the drivers side rock slider last year and left it out until this project is done. But I do want to put it back in.

 

[Gary Lewis]

It looks like with the radius arms back in the stock position that the radius arm brackets and the Atlas will both have about the same clearance. Could you put a plate off the radius arm bracket to protect the Atlas and call it good?...

I think the transfer case will be lower, but time will tell.

And I am planning on putting a skid plate under the transfer case. I don't know exactly what it will look like or where it will attach yet. That all is yet to be determined.

... And how are you going to reinforce the frame? Can you lay a piece of channel the same height as the frame on the outside and weld it on?

The plan is to re-box it by welding pieces in. I might also plate the outside of the frame. But I don't have much room for a channel there. It's wide open now, but that's where the aux fuel tank lives. I pulled that out for the drivers side rock slider last year and left it out until this project is done. But I do want to put it back in.

The strength of a frame is in the top and bottom flanges, with the sides mostly supplying the strength to keep the flanges in place. That's why Ford was able to put holes in the frames, and why bridges have webbing keeping the flanges apart.

Cutting as you have had to do to rotate the Atlas up has significantly weakened the lower flange, so you need some way to give it some strength. If you can't put channel on the outside due to the tank how about a piece of angle with the flange at the bottom?

Or, drop down and go under the notch, possibly incorporating the strengthening into the skid plate's mount?

[Nothing Special]

The strength of a frame is in the top and bottom flanges, with the sides mostly supplying the strength to keep the flanges in place. That's why Ford was able to put holes in the frames, and why bridges have webbing keeping the flanges apart.

Cutting as you have had to do to rotate the Atlas up has significantly weakened the lower flange, so you need some way to give it some strength. If you can't put channel on the outside due to the tank how about a piece of angle with the flange at the bottom?...

I know. That's why part of the reboxing will be welding a horizontal "flange" across the top of the hole, from the inner frame wall to the outer wall. I know it won't bas as effective as the bottom flange since it's getting so close to the top. But it's one of the best things I can do in the space available. That's also why I don't want to go any higher with the hole, and especially why I don't want to go through the top flange.

... Or, drop down and go under the notch, possibly incorporating the strengthening into the skid plate's mount?

That's a good idea! I was planning on having the skid plate attach to the outside wall of the frame anyway. I'll have to figure out a good way to attach it that helps with the structure as well as just keeping it in place (and that I can get at to remove, even when the aux fuel tank is in place). But it's definitely something to keep in mind. And another reason to hold off on buttoning up the frame until the end of the project, so I can think about how it all will go together best.

 

[Gary Lewis]

The strength of a frame is in the top and bottom flanges, with the sides mostly supplying the strength to keep the flanges in place. That's why Ford was able to put holes in the frames, and why bridges have webbing keeping the flanges apart.

Cutting as you have had to do to rotate the Atlas up has significantly weakened the lower flange, so you need some way to give it some strength. If you can't put channel on the outside due to the tank how about a piece of angle with the flange at the bottom?...

I know. That's why part of the reboxing will be welding a horizontal "flange" across the top of the hole, from the inner frame wall to the outer wall. I know it won't bas as effective as the bottom flange since it's getting so close to the top. But it's one of the best things I can do in the space available. That's also why I don't want to go any higher with the hole, and especially why I don't want to go through the top flange.

... Or, drop down and go under the notch, possibly incorporating the strengthening into the skid plate's mount?

That's a good idea! I was planning on having the skid plate attach to the outside wall of the frame anyway. I'll have to figure out a good way to attach it that helps with the structure as well as just keeping it in place (and that I can get at to remove, even when the aux fuel tank is in place). But it's definitely something to keep in mind. And another reason to hold off on buttoning up the frame until the end of the project, so I can think about how it all will go together best.

The farther apart the upper and lower flanges are the stronger the beam, all else being equal. So if you can come down at an angle from before and behind the cut with a strap welded to the bottom of the frame, and then fill the outside gap in the strap with plate up to the frame it'll add strength. Then somehow attach the skid plate to that.

[FuzzFace2]

The farther apart the upper and lower flanges are the stronger the beam, all else being equal. So if you can come down at an angle from before and behind the cut with a strap welded to the bottom of the frame, and then fill the outside gap in the strap with plate up to the frame it'll add strength. Then somehow attach the skid plate to that.

It might be to late but what if you took the part you cut out and flipped it top to bottom and turned it 180* and welded it to the top & bottom then make plates to fill in the ends to close it off.

Is that what you were saying Gary?

Sometimes I have a hard time seeing what someone is saying on things like this.

Dave ----

[Gary Lewis]

It might be to late but what if you took the part you cut out and flipped it top to bottom and turned it 180* and welded it to the top & bottom then make plates to fill in the ends to close it off.

Is that what you were saying Gary?

Sometimes I have a hard time seeing what someone is saying on things like this.

Dave ----

I don't think so, Dave, but then I'm like you and really haven't gotten my head around what you said. But I wasn't talking about using the bits that came out. Instead I was talking about strap and plate, as shown below.

This view is from the inside of the frame looking out, and the strap would be welded to the bottom of the frame ahead of and behind the cut. The plate would be welded to the outside of the frame, or maybe bolted, and welded to the edge of the strap.

[Nothing Special]

I don't think so, Dave, but then I'm like you and really haven't gotten my head around what you said. But I wasn't talking about using the bits that came out. Instead I was talking about strap and plate, as shown below.

This view is from the inside of the frame looking out, and the strap would be welded to the bottom of the frame ahead of and behind the cut. The plate would be welded to the outside of the frame, or maybe bolted, and welded to the edge of the strap.

What Gary is showing is what I'm thinking about after his previous post. But rather than have the "strap" be the width of the frame rail (which I think is what Gary was saying), I'm thinking of having it be the entire width of the frame, going all the way to the right side of the vehicle. In other words, rather than adding a strap I want to see if I can tie the yet-to-be-designed skid plate in well enough that it's the reinforcement.

The main hurdle will be figuring out how to attach it to the outside of the frame. If it is actually the skid plate I can't weld it. If it's intended to be the frame reinforcement it can't just be a couple of bolts. And the aux fuel tank living there complicates things.

If I can't figure that out I'll likely do something like Gary is suggesting with a separate strap. But I'll have to see what it all looks like as I get to that point.

[Gary Lewis]

What Gary is showing is what I'm thinking about after his previous post. But rather than have the "strap" be the width of the frame rail (which I think is what Gary was saying), I'm thinking of having it be the entire width of the frame, going all the way to the right side of the vehicle. In other words, rather than adding a strap I want to see if I can tie the yet-to-be-designed skid plate in well enough that it's the reinforcement.

The main hurdle will be figuring out how to attach it to the outside of the frame. If it is actually the skid plate I can't weld it. If it's intended to be the frame reinforcement it can't just be a couple of bolts. And the aux fuel tank living there complicates things.

If I can't figure that out I'll likely do something like Gary is suggesting with a separate strap. But I'll have to see what it all looks like as I get to that point.

If it goes under the Atlas to be the skid plate then I think it has to sit lower than if it is just reinforcement. So what if it was two parts - the one I show that is wider than the frame rail by ~2", and a skid plate that bolts onto that with spacers that drop it down enough to go under the Atlas.

The ~2" lip, sticking in, is to bolt to. But that also means it'll have to go lower than if it was just the width of the frame.

On the other hand, if the strap was just the width of the frame but was thick enough I think you might get by with two holes in it to bolt to. That would minimize the drop in the strap, but then you'd have even more of a need for spacers to get the skid plate under the Atlas.