Cayman Islands DIY M416(US) / M101 (CDN) trailer (2 Viewers)

[mmajsw]

So here is the deal. I have 4x6 utility trailer that I built about 20 years ago with a Dana 60 axle out of a Ford E350 van. I was going to build a second trailer to use for expedition purposes but decided that since I never use the first trailer much, I might as well convert it to what I want.
My top 10 reasons for wanting to build a M416/M101 type trailer are:-

1. I like the looks of it.
2. I want to have a place to store /carry items when making trips to the beach - cooler, fridge/freezer, generator, water and other associated camping stuff.
3. I like the concept.
4. I want to create a weatherproof structure so no worries of things getting wet.
5. I like the looks of it.
6. I will need to carry a kayak or sleeping tent on the top.
7. I like the concept.
8. It is expensive to buy a used military trailer, ship it to Miami and then to Cayman plus no parts are locally available.
9. I like the looks of it.
10. I have a few ideas I would like to try out.

So, without any further ado, it is time to wade into the project.

This is what I am starting off with. 3/4"AC painted plywood sides, front and back. Pressure treated 2x6 on the flooring which I will keep for the strength it provides. I will have to make then fit better to seal out dirt and water intrusion from the bottom.
Inside will be coated with bed liner and a suitable cover will be made.

Inside dimensions are 47" wide x 76" long x 23" high.

The perimeter frame is 2"x3"x1/4" steel. Tongue is 2"x2"x1/4" 2.5"x2.5"x1/4" and runs the full length of the trailer box.
Crosspieces are some 3/16 galvanized metal I had picked up somewhere that was about 6" wide. There are 4 of them in the inside. All joints in the frame are fully welded.

It has been load tested with 2 cu. yds. of sand and survived with no problems. The current tires are 235/85R16 and I will probably end up keeping them for now. I do have spare Land Cruiser rims that can be used in the future if needed.

The depth is good for me as it allows two milk cartons to be stacked upon each other and still stay below the trailer rim. It also allows 5 gallon bottles of water to be carried.

The tailgate just drops in but a hinged unit is in the books.

Some of the smaller pieces of metal will be replace - the tongue to body brace pieces to start things off.

 

[mmajsw]

I have decided to list some of the options I would like to have in the expedition trailer. Some are just wishes that may never come to fruition, while others are readily done. It is not too different from other builds.

This is not an exhaustive list, and will probably definitely evolve as the construction progresses.

Axles – while there is currently a Ford Dana 60 full floating 5000+ lb capacity axle in place (minus the differential, diff housing and axle shafts), it terminates in hubs that require 8 bolts on a 6.5” circle – different from the Toyota 6 on 5.5”. The Dana 60 hub diameter is 120mm while the Toyota full floating axle in the FZJ80 is about 105mm. So it is no possible to mate the two as I do not want to modify the rims.

The other option was to somehow adapt two 3500 lb. hub stubs that I already had with the 6 on 5.5 bolt pattern into the existing axle. Don’t believe that that can be done is a safe manner. Hence, I will be making a new axle

For the build, I am looking at a couple of major ideas items,

Weatherproof assembly – this means a cover with rack and proper, sealed doors. I am looking at a bedliner lined interior and a sealed outside to stop water intrusion. I am currently looking at a plywood body covered in fiberglass – like a boat build. It is affordable and very DIY. The metal trailer sides and frame will be supporting the plywood. The only question is do I build the plywood box then fit the metal frame or build the frame then fit the plywood? Leaning towards the latter right now.

Ability to carry extra fuel and water. I will be looking at around 30 gallons of fuel and around 30 gallons of water. They will be low in the frame or below the frame and will have suitable pumps. The aim is to have around 1000 mile fuel range.

Battery box – definitely a tongue box is called for to hold the deep cycle battery and associated electricals. Solar charging is something I will explore.

Spare tire – a strong enough rear door should be able to carry a tire on it. Or bolt it to the rear of the trailer – either way will work.

Lots of other things to add, but I need to build the trailer first. The first thing is to take the old trailer apart..

 

[mmajsw]

Today I started on the axle. I had checked the local metal supply store for 2x2" tubing that was 1/4" thick but they do not carry it any more. I had to settle for a piece of 2"x2" tubing 3/16 thick. This meant that I needed to make shims to make up the difference.
Starting with the hub, I took a piece of 1.5"x1.5" angle that was 1/8" thick and proceeded to machine and grind it to act as a shim. I got two pieces 3.5" long which suited my hub which was also 3.5" long.
The hub dimensions are shown below. The pic was stolen borrowed from the internet and dimensions changed to reflect what I had. I crossed out the stolen because I returned the image to the internet, right?

The first test fit of shim with spindle and axle. It was tight and required more machining and grinding.

When everything works, one gets a good fit.

What the other side of the same spindle looks like.

And there is a 1/2 space for welding.

One down, one to go. But first, I need to determine the axle tube length so that the wheel mounting surface between the trailer hubs is the same as my FZJ80 for tracking purposes. I will be using the same rims on both the truck and the trailer.

 

[mmajsw]

The Land Cruiser wheel mounting surface (WMS) distance is 63.3" in the front and 63.5" in the rear. I wanted to duplicate the 63.5" on the trailer axle. Assembling one hub together, I got the following measurements

Forgive my poor illustrations. My hands were dirty and I did not stop to take any pictures.

The math was as follows.


Axle tube length = 63.5 "- (2-3/8x2) - (1/2" x2) = 57 3/4"

63.5" = the factory WMS distance

2-3/8 x 2 = 4-3/4" Two times the hub assembly thickness

1/2 x 2 = 1 The space to weld the hubs to the axle.

The axle tubing was to be cut to 57-3/4" long and this was done.

The second spindle was inserted the correct distance into the axle tube, making sure that the shims in both cases were on the same side and leaving 1/2" space to weld.

The left side

And the right side

I will also need to drill some holes for plug welds to hold everything together. A couple on each face of the tubing should do it.
I am not happy having to use 3/16 thick tubing so I will be strengthening the axle by welding two pieces of 2x2x3/16 angle to each side for additional strength. I prefer to have it overbuild than to accidentally bend an axle.

This diagram will illustrate what is planned.

I do not expect any axle tube problems. Hubs maybe, but not axle.

 

[mmajsw]

Today was welding the axle together and installing the hubs and wheels. Nothing really out of the ordinary to report. Weld, wait for the welder to cool down so that I do not exceed the duty cycle, weld some more. I used 5/32 6011 rods at 150A on my old AC buzzbox. Penetration was great.
Tomorrow I will drill some plug holes down to the hub shaft stubs and plug weld to hold everything together.

The end result is this

A detailed view at the end with the original 3/16 axle with the additional 3/16 angle steel stitch welded to it.

Then some Land Cruiser rims and tires were added to see how everything looked.

The final distance between the wheel mounting surfaces was 63.4". I am happy.
The next step is to get the spring mounts welded it but that means removing the old axle first. And it has been bolted in for about 20+ years! Penetrating oil and heat will resolve that issue.

 

[mmajsw]

I forgot to mention that I replaced the trailer hub 2" long x 1/2" NF studs and nuts with Toyota M12x1.5 x 50mm long (I believe) studs so that I could use the same washer wheel nuts as used on the truck. It was simple knock the hub ones out out and replace with the new.

 

[mmajsw]

I have an issue that I would like advice on. I cannot get any axle bolts made in Cayman as no one will do it nor has the equipment to do so..
The current bolts around the tubular axle are 5/8" dia. I can buy 5/8 steel rod, cut it to length and use a tap to thread the ends. This can then be heated and bent to the square U shape.

I need to bolt the axle to the leaf springs. There are two choices. both views are from the hub looking down the axle tube.

1. A DIY U-bolt around the axle tube to the spring plate. Looks like this with the bolt in red. The current bolts around the tubular axle are 5/8" dia. I can buy 5/8 steel rod, cut it to length and use a die to thread the ends. This can then be heated and bent to shape. It will not be tempered but on the other hand, 5/8 dia rod can take some abuse. I can do the same thing much quicker with 5/8 all threaded rod.

2. Involves welding some 1/4" thick angle iron to the axle tube and then using Grade 2 or Grade 5 5/8" dia. bolts, lock washers and nuts to hold everything together. The ends of the angle will need some triangulating and possibly the middle between the nuts too.

Option 2 will have stronger bolts.
On the other hand, plain 5/8 rod is rated at 1800 lbs hanging capacity, it's tensile strength is 13500lbs and the shear is 7200 lbs.
Factory bolts on eBay and trailer suppliers are 1/2" diameter and usually hot dipped galvanized.
Depending on how you calculate things, I will have either 4 (option 1) or 8 (option) bolts holding the axle.
Is either of the above approaches a safe design considering the axle hub rating is 3500 lbs and my trailer weight rating will probably not go over 2,000 lbs? Or should I try and order custom axle bolts?

 

[mmajsw]

In the intervening weeks between updates, I managed to strip the trailer down to just the bed. The sides and back were bolted in rather than welded. The only problems I ran into were severely rusted bolt head and threads, which makes removing them very difficult. I ended having to cut some off with the grinder. It also makes a very good case for using stainless steel bolts when reassembling, despite the cost.

This is where I started this morning.

I began to grind through the welds that hold the front of the trailer on and it was tough. I did not realize how well they were welded in. About half way cutting through one side, I asked myself why was I removing them when I was just going to weld more corners in? I decided to take the easy way out and modify them as they are. I will be replacing the 1x1x1/4 stabilizing arm with 2x2x1/4 for greater strength.

The first thing was to make the rear corners using 2x2x1/4. Overkill but I work for free so it balances out.

Measurements were made and cuts followed after more measurements. It only takes three pieces to build the corner and here they are.
The long piece on the left is 18", the center piece is 6" and the top is 4". All measurements are along the corner of the angle.

They were clamped to the welding table and spot welded, then double-checked for correct angles.

After I was satisfied, the whole thing was welded together on both sides.

The corner above is for the left rear. A mirror image one was made for the right rear.

For now, I will be using 2x1/4 metal bar for the intermediate supports which will be 2' apart. I started off by transferring the measurements and then cutting deep grooves with the grinder and an 0.045 cutting wheel. The metal was bent to 45 degrees and I will be welding the grooves to maintain the shape and to strengthen the metal. Note that the notches are on opposite sides of the bar for the different ways it had to bend.

 

[mmajsw]

Comparing the bent bar to the welded unit and all is well. Still undecided on the cut v.s. weld option. Leaning towards the weld as it maintains the strength.

The axle bolts on the old axle as rusted in place and will not budge. Continuing to soak them with penetrating fluid. I could heat them up and get it over with but I am too lazy to move the oxy-acetylene set to the trailer. If I bring to trailer to the torch, I cannot bring it back without putting the new axle in.
Right now I am leaning to option 2 axle mounting as the most practical.

 

[mmajsw]

This morning was welding time.
Using the fab blocks that I got when I bought the table (which are great for welding), I clamped them together to get 135 degrees and then clamped the 1/4" flat bar to it.
The setup ready for welding. I have to get a couple 5/8" x 1" or 1.5" long bolts with nuts to be able to bolt the angle blocks together. All hardware stores are closed in Cayman so that will have to be done tomorrow.

And the welds and penetration were good. A bit of grinding is needed for looks

After grinding, they look like this and I am happy.

I decided to go and fight with the axle instead of welding the brackets on. If I needed to turn the trailer over, the added metal would just make for more weight. Thankfully, after a two hour fight, I was able to successfully remove the old axle and it is on its way to the new owner. I am left with a blank canvas to begin my build.

The first thing is to remove and dismantle the springs. I am going to lose the 2nd, 4th and 6th leaves counting from the top. I will be adding polyethylene strips between the leaves to reduce friction and hopefully allow more spring action.

 

[mmajsw]

This past weekend, I took the springs apart and did a bit of cleaning and lost the leaves stated above.
The initial thought was to remove the whole spring pack, but after doing some research, I decided to leave the main leaf in and remove the others.

One disassembled pack.

After wide brushing each leaf, and doing general clean-up, I reassembled the pack with polyethylene anti friction shims at each leaf end.

The next job was preparing the axle.
First, I determined the position of the spring locating bolts and drilled into the metal so that the locating bolt at the spring center would be recessed and allow the spring pack to sit flush.

I cut 4 pieces of 2" angle by 1/4" thick and 5.5" long and welded each piece to the axle shaft. They were centered on the hole and are flush with the top of the axle tube.

Using 5/32" diameter 6011 rod at 150 amps. Good penetration and lots of welding to be done. Time was spent not overheating the welder as it only has a 20% duty cycle. A heavier duty unit is on the way - a 1985 Lincoln Idealarc 250 AC/DC round top tombstone model with a 50% duty cycle under 200A.

Once the welding of the angle iron is done, the next step is to triangulate ends and possibly the middle with more 1/4" steel for added strength. It might be overkill but I believe in doing it as strong as I reasonably can.

 

[mmajsw]

It was a productive day today. My goal was to get the axle on the trailer and bolted in. And as the picture shows, I succeeded. I had to work between the short rains we had which means packing and unpacking things away but the goal was met.

A couple things extra were done. I stitch welded the 3/8 angle iron to the 2x2 tubing axle shaft. I just felt that the six or so 1" welds were a bit weak as seen in image#5. So I alternated welding 1.5" on each piece of angle along the whole length - for both pieces. Took a bit longer than planned but I am much more confident that the metal will act as one complete unit now.
Then it was measure and drill 5/8" holes to allow everything to be bolted together. I managed to get this quick image of the mounting plate before the rains came down again and stopped all work.
Rough measurements say that things are pretty well all lined up.

Springs are now showing some movement when the trailer was lowered to rest on the wheels. I have the old leaves I took out so the springs can be made stiffer if needed.
I can now pay attention to the body and look at installing some shock absorbers.

 

[mmajsw]

I have been welding up the side slowly during the week. As the sun sets later, I can get home and spend an hour or so setting parts up and welding.
The driver's side supports are complete and I am now working on the passenger side

Everything is at the same height and I should have the rest of the side supports and top rails welded by this weekend.
Note that the front corner support was cut using a 22.5 degree angle and bent so that I did not end up with the strange top piece that is seen in the back. The two middle supports do flex to be in line with the corners.
I will have to grind the welds smooth so that the metal is flat. Side welding is not my strong point although the vertical did come out quite good. Penetration is there so it is a strong joint.
More pictures this weekend.

 

[LAMBCRUSHER]

way to make it happen!!! more than one way to skin a cat... keep it up!

 

[mmajsw]

Thanks LAMBCRUSHER. If you can't get it, at least try and make it!

I managed to get everything welded up and measured out so the top support of the trailer is now complete. The only issue was the welding. I started out with 6013 rod because it is medium penetration. But when trying to do the vertical welds, the weld puddle just kept dropping off - it was not freezing quick enough. I thought that 6011 would have blown through the 1/8 thick metal, even at low amperage. After a couple welds with the 6013, I went back to 6011 and was a happy camper. Redid the 6013 welds and finished off the job.
And this is how it looks!

Before I welded the top supports, I considered building the box, drop it in and then weld it up. But that would not have been practical. The new plan is to build the two sides, the front and the bottom in individual pieces, then drop them in individually. The pieces can be fiberglassed together with filleted joints.
I will also brace the back with a bolt in piece of 2x2x1/8 angle at the top of the sides. It will help reinforce the back end but can be removed if needed for whatever reason. Need to design and build a tailgate.

Right now, I am leaning towards having the spare tire mounted on the tailgate, but that will mean a swing-away gate. The other option is to build a tire carrier so that the tire will swing out of the way, and the drop down tailgate can be used as a table. Liking the latter idea better as it allows tailgate use.

I still have to plan what options to weld in font and behind the tires - things like a propane tank holder (have to use the 20lb ones as the small 5 or 10lb units are not available here), jerry cans, ammo boxes and whatever catches my imagination.

 

[mmajsw]

Over the past week, I have been building fenders. A hour or so every afternoon allows me to me steady progress.
Fenders were made from 1.25x3/16 angle iron and this is how they were done. I was trying to use up what metal I had before going to but more.

The first thing was to determine the total length of each side. I ended up with 4' long. Then the design was made - 24" straight with each end side bent down 45 degrees and welded. This is what each side looked like sitting on a sawhorse. 4 were made.

Then I cut for pieces of 1"x1"x1/8" square tubing 12" for the end supports. I had previously determined that a 12.5" wide fender would give me full tire width coverage. Each side was tacked welded and checked for 90 degrees both ways before fully welding then in.
Then the matching side was added, ensuring that the width between both sides was uniform. Once all measurements checked out, the second side was secured. I did not weld the V notches for two reasons. First, the open notch gives me a greater welding length to keep the fender on. Secondly, there was some warpage when welding it together and I wanted to use that to my advantage as much as possible when installing them.
Finally, I welded two pieces of 1" x 1/8" strap in 1/3 intervals to keep the sides of the fender secure.

The fender was then test fitted and clamped in place before being welded in.

This shot shows the end of the fender and the overlap to the frame. The end was welded to the frame.

After the position was determined, the fender was then welding into position. This image shows the increased welding surface caused by the unfilled V. There is a lot of slag in the picture.

And how the fender looks from the back of the trailer. You can see the 1x1/8 strap in this image.

Repeat for both side and the framework is done.

 

[mmajsw]

The view from the back showing left fender. It looks like it is on an angle but it is 90 degrees to the frame. Picture distortion.

With the fenders basically completed from a welding point of view, I turned to the trailer tongue brace. I had previously used 1x3/16 angle and upgraded it to 2x1/4 angle. That will be strong enough for my use, The old braces were readily cut out and the new ones were trimmed to fit and welded in. A couple strips need to be added between the braces and the frame as they are only butt welded at the moment.

I have to move the trailer jack to make space for the next item - a tongue box.

I had marked out the size on the trailer and began to cut the base out when it was time to call it a day. I had a few pieces of bed frame lying around so decided to use those here instead of buying more metal.

I will continue the box during the week. There is also a lot of painting to be done to protect the bare metal from rust!

The next big item coming up is plywood and epoxy fiberglass!

 

[mmajsw]

The little triangles missing from the fenders were added, welded in, ground smooth and painted.
I removed the rest of the 2x6 flooring and you can now see the bracing that is underneath.

The next step is the shocks and painting of the underside. So we flipped the whole thing and sat the trailer on it's rear, tied off to a couple trees for safety. It is stable and the tree tie off was in case anything movement happened, it would be away from the person working on the bottom. This will only be for a couple hours as finishing off the bottom is a priority so that the trailer can be placed on it wheels ASAP.

 

[YMT]

I like how you've fabbed the sides and am anxious to see the finished product. Do you have a final, empty weight as a target? I would suggest not using the 2x6 floor, since you won't be able to keep out the sand/dust.

 

[mmajsw]

Hi YMT. I have no weight goal. And no idea as what it even weight right now but three of us easily lifted it up on its back.
My couple days on its back has turned into a whole 10 days and counting as the rain continues to fall in Cayman from Invest90, just southwest of us. Maybe this weekend might allow some time to work on the trailer.