The Road Ranger. 1997 SEMI

[Rick W]

Step Trailer Update:

The Road Ranger and step trailer are motoring down the road great. But I noticed the framework for the trailer “pin” is scraping the truck bed, on the inside corners where the “fifth wheel“ assembly is, when I’m making turns. When I first built the trailer, that fabrication was hitting the back fenders on a sharp turn, and I had redone it all before I went up for nationals this year. I measured it 1000 times, and before I finally welded it, I went in the church parking lot across the street and drove it every which away and in circles and turns. Everything cleared. But I can see the scuff marks, and of course that scares me, I don’t want to bind it and break something.

I haven’t gotten much done with all the hurricane Rugrat refugees in the house, but I took a couple of them across the street, and I did everything to that truck I could think of, measuring everything, and I think I figured it out.

I don’t have the classic pin in the plate fifth wheel. It’s an upside down ball trailer hitch, so the trailer can tilt side side. I knew that, and I thought I had still left plenty of clearance for anything that would happen on the road. And it looks like I was right.

First, the bed of the truck tilts up a little bit towards the back. That was by design a little bit, so when I have a load, it will level out. The only place it’s scraping is on that last 2 inches, on top of the light assemblies. That’s 1/8 inch aluminum on top of some fairly thin 2 x 2 tubing. The pin pivot point isn’t centered between the two axles, it’s actually just a few inches in front of the back axle, which was also by design, so the truck would “pull” that axle and the trailer, not “carry” either one.

Since the city widened the road and put in a slightly elevated sidewalk at the end of my driveway (that’s now a steeper incline), there’s a pretty pronounced hump. That sidewalk/hump is right under the rear wheels when I turn left or right out of the driveway.

Apparently, when I pull out and I’m turning, the truck will tilt as much as 6-7 inches from one side to the other, which doesn’t happen on the road. At the same time, the back wheels of the trailer are still sitting square on the driveway. That one location/turn is apparently where I’m getting interference.

There’s only a scrape on top of the light assembly on the left. When I turn left, I have to cross the lane on my side of the road, so it doesn’t tilt as much as if I turn right. On the right, the pin assembly has actually caught on the inside corner of that part of the bed, and actually bent the 2x2 tubing, crushed it, about a half inch. I figured out that happens because it’s a much tighter turn to the right creating a bigger slant on that hump..

The frame and fenders are all attached solid to the truck frame, it’s only the axle that floats underneath it. When I did my twist and turn test across the street, I also realized that in tight turns that rear axle will move left or right about an inch to either side. No big deal because it tracks going down the road, but that has the effect of moving the pinpoint to the left or right, which affects the clearances in a tight turn.

With all that, I would have to make some pretty substantial changes to the 2 x 2 frame I installed on top of the truck frame in the back. The other solution was just to use a longer offset hitch for my pin, which just raises the assembly up a couple inches. That’s easy to try and remove if it doesn’t work. So, that’s what I did, I swapped out the 4 inch offset for a 6 inch offset.

One of the other reasons I redid that whole pin assembly before nationals, was because the trailer was not square left to right with the back of the truck (just top step deck). It also slopes up a little bit towards the front with that same idea that when there was a load on it, it would all level out. I haven’t seen it on level ground since I swapped the hitch, but I’m concerned it might slope up too much now.

I can fix that by correcting another oversight. On the rear of the trailer when I put my axle mounts on the frame, I put all three the same on each side. With the double axle and the equalizer, the one in the center should actually be longer so it hangs lower. Now, the springs can hit the bottom of the frame when I go over a speed bump or something like that, they’re not totally free on that equalizer at its limits.

So my plan is the next time I hook it up, which will be Saturday, I’ll measure it all out again, and then replace those middle spring/equalizer mounts with longer ones that will level the trailer front to back where I want it. That will bring the tail end up a couple inches, but I can live with that.

I now have all my brake parts to do the brakes on those two back axles, so I’ll just do it at the same time, but not right now.

Two points in presenting all this.

First, I would want everybody to have the most up-to-date information and findings if they’re going to try to do something like this, buttt….

Second, I’ll reiterate my disclaimer again that I don’t advise anybody to do this, certainly not the trial and error way I put it together, it’s all a toy for me, and I make no representation about the road worthiness or load handling capability, especially if someone put a serious load on such a thing. I have a unique combination of engineering experience, hands-on, mechanical and fabrication experience, experience with trucks and trailers, etc. that makes me feel comfortable with what I’ve done. But in this posting, there is certainly not a design for others to duplicate.

But it is a blast!

 

[Rick W]

I forgot to put in the picture of the special equipment I used when I was measuring everything, as well as a couple pictures of the damage.

On the right, that’s an every day pair of dollar store needle nose. You can’t have enough of them. Spread out across your workshop.

The red bar and pointer device is a premium SW&CH hitch level and alignment tool sourced from the SOM. (scrap wood and coat hanger from the shed of miracles). A scrap piece of a 2 x 2 pressure-treated stake, and scrap pressure treated 1 x 2 painted red from a different trailer project. The 1x2 was measured, centered, and notched to sit level across the bed, with the 2 x 2 at a perfect 90° angle to sit in the tightly in the coupler at deck level, fasted with a couple of scrap screws from my scrap screw bowl. I did use a good sheet rock screw for the pivot point.

I actually switched to a virgfull-size coat hanger and cut it up and straightened it with a loop on the end because the white one in the picture was a drop scrap from a coat hanger partially used from who knows what, that was about a half inch too short.

It seems silly, and I presented silly, but A lot of getting the job right is the right tools even if they’re not commercially available. Of course I use pressure-treated for durability so it will last between the tractor trailer projects..

 

[sgtsandman]

The only thing I can say is, when you blaze a new trail, there is going to be bumps and scrapes along the way.