DISCLAIMER: I had no prior experience in trailer fabrication prior to making my own car hauler. However, I did use my near 20 year experience in trucking to help me along. I’ve learned a lot during this project but I must stress that what works for me may not be what will work for you. These DIY tips are a “take it or leave it” thing!
I recently received an email from someone who liked my trailer design and wants to build his own trailer. He had a few questions for me and I thought that I should share the information that I passed along to everyone else interested in fabricating their own hauler. This will be in Q & A format (I’ve added a few on my own).
Q: Would you be willing to share more details of the aluminum trailer that you built; dimensions, sizes of channels, etc?
A: On top of my head, I simply cut 20 feet long 3″x2″ channels into 3 equal pieces each to make the seven cross-members plus the two frame ends. That makes for 2 feet cross-member spacing. That will net you a platform (deck) that is 80.5 inch wide and 16 feet long when completed. However, that can vary depending on the length you decide that you want your deck to be. I used 1/4 inch thick aluminum as “overkill” just to be sure it’d be strong enough but I reckon you could use 3/16 inch thickness. For more info on my frame design, CLICK HERE.
Q: Where did you source the axle mounts?
A: I was to fabricate my own axle mounts but the shop where I sourced the axles made me a price too good to pass up. I had them made out of stainless steel for strength and rust protection. They are not difficult to fabricate and, if you don’t feel up to it, any fab shop can make those for you. The spacing of the brackets will depend on the axles, suspension, and the desired ride height. Any trailer parts store will be able to figure that out for you if you explain what you want.
Q: Where did you buy the tilting / swivel / moving fenders?
A: I simply used generic aluminum fenders for a tandem application. The tilting/swivel system is of my own design and fabrication. It’s not hard to do, just look at my pictures and you’ll figure it out: CLICK HERE. It was inspired by rental units I once used.
Q: Did you use a company or shop to help design your trailer?
A: Not at all. However, I did use various visual sources for inspiration. I custom fabricated it to fit my particular needs, such as available garage space, size of my rally car, and more importantly my budget. Being inspired by someone else’s design is fine but it should not be replicated down to the minute details. I would strongly suggest that if you are willing to take the time and effort to fabricate your own trailer that it should be what you need, what you want, and how you want it. If this is your first rodeo, I would recommend that you go and eyeball commercial units for sale. The internet, as always, is a quick and easy way to check out multiple designs too.
Q: Why did you go with a flatbed / flatdeck design?
A: As per my experience in trucking with such units, although the size doesn’t compare, they make a versatile trailer for hauling almost everything that needs be hauled.
Q: Wouldn’t a dovetail design have been better for car hauling? I.E.:
A: I had considered it but my driveway has a strong incline. I once rented a similar trailer to haul small machinery and a rear corner of the dovetail would rub on the asphalt due to reduced ground clearance. Secondly, my 12 feet ramp system would not have worked with such a design. In brief, it had too much cons than pros, for my own usage that is. It doesn’t mean that it wouldn’t work for you though.
Q: Why did you choose aluminum instead of steel?
A: Wintertime is exactly why I chose aluminum for my trailer since I am in Canada. Salt will make a mess of a steel trailer in just a few years. It also makes for a lighter trailer, which in turn helps fuel economy as well, but admittedly it is a metal harder to fabricate with. That being said, try to isolate any steel parts from the aluminum frame. Using duck tape is the easiest way, or a thick coat of paint works as well. That avoids electrolysis between dissimilar metals which will make them rust sooner that normal. If that cannot be avoided, use galvanized or stainless steel parts/hardware.
Q: It’s looks like you used a 3 inch square tube for the tongue?
A: Yes, however, I would recommend that if you go for a long tongue like mine (4 feet protrusion from the deck) that you get the thickest gauge available. Mine was 1/4″ thick and I observed a lot of up and down flexing when someone was jumping on the deck. For long term safety, I hammered another 3/16″ thick aluminium tube tightly inside the tongue, making a total thickness of 7/16″. Furthermore, be certain that your tongue beam reaches at minimum the 2nd cross-member (mine reaches the 3rd for added strength), and safety guidelines require, in addition to welding, that you add a bolt to the tongue beam and your “anti-twist” V-shape beams directly to the frame. If your welds ever fail, those 3 bolts will most likely save your life.
Q: How did you determine where to put the axles?
A: Normally, it is suggested (on a car hauler) that you use a F60/R40% split, meaning that the centerline of your tandem axles is at 40% of the length of your deck from the rear (or at 60% from the front, same thing). Under normal conditions, that will prevent your trailer from titling on its rear due to load weight (if uncoupled from the tow vehicle). However, for my application, I went with the reverse weight bias of my rally car (F55/R45%). Meaning that, on my 16 feet deck, the centerline of my tandem is at 7.2 feet from the rear (or 8.8 feet from the front). That makes for a perfectly level trailer/pickup ride height. Remember, the closer you go to 50%, the easier that the trailer will be able to be moved by hand, but you risk titling it if more load weight is on the rear. I suggest that you do not go rearward past the recommended 60/40% split since that will balance the weight forward and can possibly overload your tongue weight rating.
Q: How did you align your trailer’s axles?
A: It is important that you use triangulation from the tongue’s tip when drilling the left and right side mounting holes for the axle brackets. This is the way that you do the alignment for a perfectly straight tracking of the trailer when going down the road. If you don’t do this, and simply drill the holes at the exact same measurement on both sides, your trailer may track a bit sideways behind the tow vehicle. It depends on how far off you were on perfectly squaring your trailer frame and tongue. It can also make for uneven tire wear and reduced fuel economy.
Q: How much did your trailer cost you to fabricate?
A: Without getting very specific since prices vary wildly by location and country, my aluminum car hauler has cost me, in materials and parts, just about the same price of a similar commercially available steel unit. However, like I said, it is tailored to my needs and I like to fabricate things on my own so it makes it even better. It’s also a bit flattering when people walk up to you and ask where you bought it… then you can proudly say that you fabricated it yourself!
Q: Do you have any other suggestions?
A: As I’ve said before, research multiple designs, and find out what works best for you based on; main usage, tow vehicle (towing specs, ground & hitch clearance, etc), season(s) of use, type of cargo, expected length / width / height / weight, load ratings, possible accessory need (chest, winch, extra storage, spare tire, etc), attachment / anchor points location, available work / garage / yard space, availability of tools / materials / parts, legislation (i.e: DOT rules, local long term trailer storage rules, etc), and last but not least your budget.
Q: Do you have any future modification plans for your trailer?
A: Now that the sliding tarp system is done, there is not much else to do but improve upon any weakness that I might find in the future.
Do you have more questions for me? Then simply use the CONTACT ME form and I’ll add it on here!