You want to make sure you have some tongue weight.  Otherwise when you hit a bump the trailer is going to throw the rear end of your tow rig around.  You want around 10% of your trailers total weight to be on the tongue.

http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/tongue-weight.htm

So it really depends on what and where you put things in the trailer on where your axle needs to be.

One thing to remember:

Max towing capacity on a Samurai:  1000lb
Max towing capacity on a Tracker:  1000lbs without trailer brakes, 1500lbs with trailer brakes.

Stock weight on a 4 door is around 2700lb, so you are going to have to shave off over 1200 lbs in order to safely pull your trailer IF you install trailer brakes.  That means you are going to have to swap over to some trailer axles.  Otherwise you are going to have to cut down 1700 lbs in oder to safely pull the trailer around.

Yeah, that axle's got to move forward. Stock numbers for towing capacity are kinda out the window. It's based on vehicle breaking power, and torque. Those things are going to be modified from stock. The tow vehicle will be 500-1000lbs heavier, the breaks are getting beefed up with the Yota axles, and I'm putting in the 2.7L V6. I should have more than enough weight & tire contact patch to keep traction, loads of breaking power, and pulling power to spare.

I'm mostly concerned about the welds. I don't think I used enough amperage to get good penetration. Thinking about re-practicing on scrap, grinding the existing tongue welds down, and starting over. Will kill another couple days, but better to do that than watching my trailer fall off. From there, it's all about putting the trailer on a diet.

Leaving the roof on?  Or cutting it off?

I think keeping it on will look better, and provide good shelter and security for all your crap.

When you move the axle forward....are you going to move the wheel wells too?   The doors would be an obstacle for that kind of fabrication....but I think it would look goofy/ugly if you keep the existing wells, and have the wheels in the middle somewhere.

If anything...you could probably just cut out the wheel well humps on the inside to give you more room inside, and cover them up if you aren't using them.  I'd photoshop something for you....but I suck.

Okay, to add some tech, looks like the XL7's towing capacity is 3500 lbs. Since I'll be using it's power plant, be at a similar weight, and have better breaks - I think I'll be okay.

Roof is staying on. I'm kinda screwed no matter what way I go, but function's more important to me than form. There's not really any room to move forward without getting into the door. I can go about 6" forward from where the Toyota axles are now before rubbing. There's a few ways I can think of to do this right now:
* For looks, I think I can weld over the rear wheel wells to make it look better (maybe a battery box on one side, and a "compartment" on the other?)
* I can install 27"ish wheels on wide axles, cover the lower part of the rear doors, and make some kinda exterior fenders. Maybe i can cut the rear doors in 1/2 or something to keep side-trailer access (front doors are going to be removed for 1/2 doors on tow vehicle). Something like this maybe:



* I can find some small tires that will fit under the rig (may have to do tandem axles - wonder if I can do two axles on one spring?), and still leave room for suspension travel.
* I can install 27" tires as far forward in existing wheel well as possible (about 6" further forward than the 35" pictured), and cut about 12-18" off the front of the body & frame.
* I can install 27" wheels with a 3" body lift (I want to avoid this, but it's not ruled out)

As far as trailer brakes, what about using a hydraulic master cylinder/tongue from a boat trailer or car hauler, and tying it into the original rear drum brakes?  Might be easier than setting up an axle for electric brakes. 

I'm going to gamble towards stripping weight off, which means switching to lighter weight axles. I'll keep the tracker axles around for a while just in case, but hopefully I can avoid trailer breaks all together.

I think my towing capacity will be around 3500 lbs, and the loaded trailer will be under 2500 lbs. At least - that's the plan.

You want to make sure you have some tongue weight.  Otherwise when you hit a bump the trailer is going to throw the rear end of your tow rig around.  You want around 10% of your trailers total weight to be on the tongue.

I can't find my handbook right now but I'm pretty sure that the max. tongue weight is 50kg/110lbs. Thats with our (UK) very generous towing limits.

On welding, crank up the amps. You don't have enough heat or penatration.  Clean the area where you are welding, (ie... grind the area that is going to be welded).

Your welding to rusted and painted steel, need to clean that stuff off.  Take your time and practice on some scrap before making your final pass.

What type/make welder are you using? Pic?

Montgomery Ward 295

Ah, old school.

Like I said before, make sure your metal is clean.  If you weld over crap your welds will be crap.

Also, make sure you are using the right rods and that they are fresh (have not been left out in the weather or have been wet).


Good luck.