Ultimate 4x8 utility trailer, 2,700lb capacity with brakes
 

This is what I have been moving toward with the odd questions I was asking.

http://ecomodder.com/forum/showthrea...ire-34883.html

http://ecomodder.com/forum/showthrea...5-a-34939.html

Pretty much a ground up rebuild.
This trailer started out as a bolt together motorcycle trailer with about a 900lb capacity in 2004. I got it in 2008 and rewired it, put a new hitch on it along with better tires, axles and springs.
Last time this trailer went under the torch was 2012. I converted it from bolt together fold up to ridged welded frame. On top of a 2,000lb idler axle and about 1,800lb worth of tires.
On my road trip last year I could feel the deficiency in the tongue design on very rough roads, roads in NY are worse than I have seen in war zones, WTF is up with that. And the mild 800lb gross trailer weight was pushing the car around a lot more than I would have liked when I tried to stop.
So it's getting a brake axle and new tongue design.
The spindles are ez-lube brake hub ready spindles rated 1,350lb each using 1-1/16'' inside and outside bearings. The axle is a schedule 80 steam pipe measures 1.5 inch inside diameter.
Ez-lube means that the spindle has been rifle drilled with a small hole from the spindle nut to between the grease seal and inner bearing. They should probably call it lazy lube. The only reason I want it is so when I get a surprise long distance trip I can hit the bearings with some grease with out taking the spindle apart.
It's still a good idea to clean and really pack the bearings every 2 or 3 years.
The axle and spindle are at the machine shop being machined down to fit together, I weld them.
The spindle bases are bigger than 1.5 inches, so they don't fit into my choice of axle tube.

Looks like the tires I will be going with will be load range E 145/80R12 rated for 1,600lb each.

Total cost of the brake axle up grade is going to be around $550.
The brake drums, brake set and spindles were all about $270.
The tires and rims will run about $200 for the pair.
Heavier springs are $25 each at the local trailer supply.
6 foot of schedule 80 steam pipe was $24.
I didn't ask how much the machine shop was going to charge.
And I need to find some U bolts.
I should have all the nuts bolts, hangers and shackles.
If you wanted to do one your self you could definitely save some $ by going with cheaper tires if you don't need load range E and if you stuck with cheap steel rims or even better, used steel rims. I want new aluminum trailer wheels.

You may think 2,700lb gross and around 2,400lb capacity is way too much for a car. IMO a 800lb gross weight no brake trailer is too much for most cars. but I also have the suburban and the over powered big brake firebird.

My friend's dad had a pretty scary encounter with losing one trailer brake.
Driving along one day on the interstate with the family camper behind a half ton SUV at some point something, likely a peice of tractor trailer tire severed the wire to only the drivers side trailer brakes. He was unaware this happened.
When he got in the off ramp lane he put on the brakes and it put him back in the left lane. Lucky there were no other vehicles around.
Hit the breaks again and it almost put him off in the median.
This guy is a cop so he has had plenty of driving training and is really cheap, and will run tires till they fail. So he has had plenty of trailer tires and vehicle tires fail, more than I ever will and I have had a lot. So he has a lot of experience when things go bad.

So to prevent this I was going to test what happens when I wire the brake coils in series. I'm thinking that shouldn't really be a problem since old style brake controllers used a really big resistor and only sent a few volts to the brake coils under most braking situations.
It should only cut braking force in half and you use under half braking power practically any time you hit the brakes.
This way if one brake quits because of an electrical break then there will just be no brakes on the trailer.

Actually I feel the best thing to do would be to run multiple brake wires to the trailer in multiple directions!! The power is pretty much split between the two so having a wire go along the axle will having two others go to the front should give better redundancy!!

From what I understand with what your talking about oil pan there will be only one wire going to the brakes in the end?!? Which could still cause a problem because the one that most likely will break is the one running along the axle!!

The magnetic coils could still burn out.
They may not even work very well in series, only way to find out is going to be to put the axle on with the coils wired in series.
The way I wire stuff I would run the brake wires into the trailer tool box and attach them to a terminal block.

Most trailer axles run the wires inside the tube. I prefer to run separate pairs to each brake from the junction box. My brakes work much better with the grounds hard wired all the way.

Yeah I started wiring grounds all the way back to the trailer plug back around 2008. A bad ground is what causes the lights to not work most of the time.

Run your wiring inside conduit. Is how I've seen a lot of cattle trailers setup , to armor the wiring for brushy pastures.. my preference is for Tekonsha brake controllers based on info circa 2000. They have a confirmation of connection to the brakes and ground. It has a pendulum to ramp up the brake power based on g force. . Had my 7way plug get striped by a stick . Saw the led went out so know there was a problem before it was a surprise. 4'x8' +? tung are you planning an A frame or pole?
Glad you see fit for brakes most states require them at 1500lbs and the average shoper is unaware that they have to modify a 2000lbs Harbor Freight fold up to be leagal.
. Looking forward to pictures.

Helpfull hint
Always test the application strength for the current load before taking off . I learned that the hard way . Me my wife my kid some one played with the knobs between tows. City 25 mph first brake application above 2.5mphI had to hit the brakes hard . Some jack head pulled out in front of me @21k lbs. I had the up to 6 axel controller on a 2 axel 8000lbs ea turned all the way up and off level. It tryed to lock the tires 1 axel did as told 1 axel crushed the spring hangers , twisted the U bolts and spun 3 revolutions winding up the slack in the wiring disconnecting the brakes. Made me glad for 4wheel disk brakes on my 79K-20 . Fortunately the other driver realized the way was suddenly cloudy and raining 5thwheels and stoped clear. I was able to lemp to the new spot and had to call in a warranty claim as the traler had about 2000mi all asphalt in the previous 6 months . The trailer was bought new so no abuse from previous.

The trailer brake coils ohm out at 4 ohms each.
That is likely too high to series and be effective.
I will wire everything back to a terminal box so all I have to do is switch a few wires if it doesn't work.
Still waiting on the machine shop to get to my axle. They are going to press fit the spindles into the axle.
When I get a lathe and milling machine it won't be to save money, I can afford the machine work, the waiting is the hardest part. It will be done to save time.

I took my little trailer to Lowes today and loaded it up with some fairly light stuff, a load of cement, sand, grout, tiles, concrete backer board. Im sure it was pushing 1,000lb gross trailer weight.
That was enough to push around my firebird. I was actually even able to lock up the 11 inch wide yokohama s-drive tires which are real sticky summer only high preformance tires with the corvette front brakes.
Trailer brakes are not a bad idea.

Still waiting on the machine shop, but they said it should be done this week.

I built the harbor freight "super duty" 1790lb folding trailer last year. I took out the bearings and re packed with good grease and built a floor out of 3/4" pressure treated and used 1/2" treated for the sides. I took it a couple hundred miles no issues and to the dump and on mulch run. Good little trailer but I don't intend to fold it.

The fold option makes them kind of flimsy.

I got my axle back from the machine shop. This week I'll put the trailer in the back yard and start working on it.

I have needed my little trailer for multiple projects so I couldn't take it apart and chop it up like I wanted when I wanted.

I pulled the idler axle off and took all the measurements I need to build the heavy duty brake axle.

Also decided what to do with my old idler axle, springs and trailer tongue.
I'm going to turn my 17.5kw generator into its own little trailer. But that will be later on.

Been working on my trailer.
The new tires have already had the special treatment.
http://ecomodder.com/forum/showthrea...air-28914.html

http://ecomodder.com/forum/attachmen...1&d=1495314300

Brake drums on the new axle.
http://ecomodder.com/forum/attachmen...1&d=1495314300
http://ecomodder.com/forum/attachmen...1&d=1495314426

Hunting down, grinding away and sand blast as much rust as possible.
http://ecomodder.com/forum/attachmen...1&d=1495314501

Aligning the new spring hangers with a threaded rod.
http://ecomodder.com/forum/attachmen...1&d=1495314592

A decent construction red-LED laser will also help you get/keep things aligned...when directed onto a white cardboard marked with cross-hair.

Since I am going to beat this thing like I rented it I welded it as if to prepare it for the apocalypse.
A tig root fusion only pass at 105 amps.
http://ecomodder.com/forum/attachmen...1&d=1495698193

Then followed by a very hot mig (GMAW) pass.
http://ecomodder.com/forum/attachmen...1&d=1495698193
And that was over head. I never weld over head.

The hitch attachment.
http://ecomodder.com/forum/attachmen...1&d=1495698723

I have been using this trailer ever single day that I have not been working, even some days I work I take it to work. I work about 14 days a month because of I work 13 hour shifts.
Been working perfect.