Originally posted by sbeninga
it says on the tire "Load single 2340 lbs at 350 kPa (50 PSI) COLD" and "Load dual 2040 lbs at 350 kPa (50 PSI) COLD". I am thinking that means single axle vs dual axle?? |
A dual axle is one with 4 wheels on it. A tandem axle is two axles one right behind the other. Tires are derated for dual axle use because they run hotter and its not possible to keep the load on them exactly the same. In your case the 2340 lbs applies. Since you have a 3500 lb rated axle (1750 per wheel) your tires have a safety factor of 2340/1750=1.34 or 34%, which should be OK, just keep them inflated to 50 psi cold (meaning after the trailer has been sitting for a couple of hours). My original 14 inch tires were only rated for 1750 lbs, giving me no safety factor at all. not good.
You should take the time to learn and set up the weight distribution hitch yourself if you haven't done so. That's because they are often set up wrong for the way you end up loading the trailer. When you hang the trailer on the tow vehicle it lifts the front axle up. Read the instructions and you'll see that the purpose of the wdh is to return the load on the front axle of the TV back to where it was before hitching up the trailer. Its not to make the tow vehicle "look level" as some folks seem to think.
So, get the trailer and TV loaded up, find a perfectly level parking lot, bring some painter's tape and a tape measure. Give yourself a couple of hours the first time so you're not feeling rushed. Put a little strip of painter's tape on your front fenders right above the front axle so you have a nice line to measure to. Unhitch the trailer and measure the height at the front axle. Then hitch up and adjust the wdh bar tension so that you get back to the same height you started with, or as close as you can. The Highlander will still be sitting lower in the rear than without the trailer, that's OK.
The trailer should also be level at that point, you might need to adjust the hitch height and/or angle to achieve that, then redo the tension adjustment. Getting the trailer level is important both for towing but also so you can pull in somewhere for the night and not have to unhitch to sleep comfortably. Once you have things set up you shouldn't need to do it again unless you change your loading significantly.
While you're loaded up in the nice big parking lot check your brake controller adjustment too. The controller max braking level should be set so that when you stop from 15-20 mph using just the trailer brakes (use you manual control on full) the trailer wheels almost lock up, but not quite. If they lock up then your emergency braking action is actually reduced. Many of us find that the rPod brakes are pretty weak and won't lock up even at full controller output, in which case you can leave the controller set on full.
Your trailer brakes are now set to give you max effectiveness in an emergency stop. The second adjustment (called boost level on my controller) sets how much braking they do under normal conditions. That is a personal choice. What I do is drive down a winding grade using mostly engine braking (I use sport mode to select a lower gear) but some wheel braking too. Then I use my trusty ir thermometer and check the temps of all 6 brakes. If the Highlander brakes are a lot hotter than the trailer brakes then I increase the boost, if cooler than I decrease the boost. I'm trying to get all the brakes sharing the job as equally as I can.
One more thing I highly recommend you do is weigh your rig fully loaded for travel. Most everyone is surprised how heavy things get, especially the tongue weight. You can do that at a public scale. If you roll one axle at a time on the scale you can get the weight on each axle by subtraction. Leave the wdh untensioned when you weigh so it doesn't throw off the numbers.
If you then drop the trailer off and weigh the TV by itself you can get the trailer weight by subtracting the second from the first weighing, and the tongue weight by subtracting to weight of the TV by itself from the weight of the TV's 2 axles from the first weighing. Then you can compare all the weights against the TV specs in the manual, the driver's door sill, and the trailer weight sticker to be sure you're within safe limits. In my case I had to readjust to get the tongue weight down to 500 lbs which is the Highlander's max. Like with the brake controller and wdh, you only need to do this once unless you make major changes, but its well worth it to understand and know that everything is safe and working as it should.