Thanks for any help!

I know you want more storage but you would be better off placing anything heavy in the Highlander, as far forward as possible. Just behind the front seats is ideal. The lighter you travel the more pleasant and safer the drive will be. 

When I purchased the R-Pod from a private party it came with the Pro Series weight distribution/sway bar hitch.  I had a long drive home from central Idaho to northern California and it really made it feel more secure to tow.  I rented an R-Pod 190 this summer to get a feel for it and the owner did not set me up with a weight distribution/anti-sway bar.  I could tell the difference.  

I slept in the R-Pod during our PG&E Public Safety Power Shutoff.  It was handy to have for heat and also a shower in the morning.  I notice a "creak?" in the plywood below while I slept.  After pulling the mattress out above I now know where the creak came from.  The larger piece of plywood is warped.  I imagine I can get a new piece from Home Depot that is not warped and replace it.

Thanks for mentioning about the tires.  I have done a lot of reading on this forum and I have seen that mentioned before.  I just went out and took a picture of the tires.  They are Westlake tires ST235/75R15, load range C  6PR CR857+.

Thanks again for your help!

I have the same weight distribution hitch, works fine with my Highlander.

Yep, just get a replacement piece of plywood the same thickness, you might even just flip it over (if its symmetrical) and see if that works.  

Re your tires, that is an oddball size not readily available, I think came on the west coast (HRE) version. I think one of our members was able to determine it is rated at 2340 lbs, which is not bad. So I think you can keep them for awhile, others might disagree. Do keep them inflated to the pressure listed on them, measured when cold. Check the pressure daily when travelling. 

You might want to get an IR thermometer like this one, check the tire temps whenever you stop for gas, if one is getting a lot hotter than another that would be an early warming of possible tire failure. You can use it to be sure your trailer brakes are working evenly too if you check it after a few stops using your brake controller manual slide lever. If one brake is much cooler then its not doing its job. 

https://www.amazon.com/Etekcity-Lasergrip-1080-Non-Contact-Thermometer/dp/B00DMI632G/ref=sr_1_5?dchild=1&gclid=Cj0KCQjwreT8BRDTARIsAJLI0KKqfe9OP6TSPv5TF208b-kCFq5FlQLKWy-h3oiZryLYsIHxBCcaPtEaAjNWEALw_wcB&hvadid=326607819484&hvdev=c&hvlocphy=9008704&hvnetw=g&hvqmt=b&hvrand=9295544025922241191&hvtargid=kwd-325254504195&hydadcr=28545_10017593&keywords=infrared+thermometer&qid=1603930454&sr=8-5&tag=googhydr-20

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. 

I like your explanation of measuring the height at the front axle.  My driveway is gravel and it is not level where the trailer is parked.  (I am going to try to get some work done on the driveway so that it is closer to level.  I want to get some bamboo removed anyway so that I can move the R-Pod over further so that I can get my Highlander back under my carport style garage.) I also like the benefit of getting the weight distribution/sway hitch just right so that I can pull in somewhere for the night and not have to unhitch to sleep comfortably.  I would imagine it would be good to put the stabilization jacks down too or not necessary??

I have a Tekonsha Prodigy P2 brake control on the Highlander. I believe it is currently set on "2" from when I rented an R-Pod a couple of months ago.  The braking seemed fine on that level when I drove home from Idaho but perhaps I should have it at a different level?? I have used the sport mode to select a lower gear.  Is using the cruise control while towing an absolute no-no?

I recently watched a John Marucci You-tube video about weighing my Highlander and R-Pod.  Is it necessary and/or better to have it weighed at a CAT scale?  The nearest CAT scale near me is quite a ways away.  There is a local concrete/rental equipment business not far away that has a scale I could use but not sure how it compares to a "CAT" scale.  I do want to have this all figured out before I travel again.

Thanks again!

Welcome to the forum. Here are a couple of things to consider-

1-you do not have to use a CAT scale-it is usually at truck stops and a fee is charged.  I used a free scale at our local land fill. you just need to load your pod and tow vehicle as you as going on a trip.  start with the weight distribution hitch bars loosened and the pod hitched to the tow vehicle. Drive the tow vehicle with all 4 wheels onto the scale and note the weight of the tow vehicle.  this is weight #1. then drive forward so that  both the tow vehicle and pod are on the scale and note the weight. this is weight #2. then go somewhere close and drop off the pod. Return to the scale and weigh just the tow vehicle again. Note the weight.  this is weight #3.

You have just weighed your rig.  the first weight is the tow vehicle and tongue weight combined.  the second weight is the combined gross combination weight of the tow vehicle and pod. The third weight is the tow vehicle itself without the pod or tongue weight of the pod.  subtract the last weight(tow vehicle only) from the first weight(tow vehicle with tongue weight) and you will have the pod's tongue weight.  subtract the last weight(tow vehicle alone) from the second weight(tow vehicle and pod) and you will have the pod weight.

2-you may or may not put down the stabilizers when stopping for a quick overnighter. the pod is still connected to the tow vehicle.  If you don't put down the stabilizers, there will be some bouncing and swaying as you walk around inside the pod, but nothing bad will happen.  Usually, I disconnect the power cord from the vehicle so as to not drain the tow vehicle battery. Otherwise, the pod is functional with it's own battery power and everything works except the AC and microwave.

good luck and safe travels

Vann

Thanks Offgrid for your additional comments!! 

In the meantime, I've also learned a lot on youtube (and often its helpful too see the explanation.) Here's one video, I think, on your WDH  https://youtu.be/d8ZRiJ-8i7w

And the opposite way to hitch up. First lower onto the ball and lock it on, then raise the jack a few inches, lifting the back end of the tow vehicle. Installing the spring bars will require no effort at all if you raised it enough.  This also proves that you are completely connected to the tow vehicle as well. Don't want to find out the hard way you weren't actually clamped to the ball. 

That's the way we do it. Crank up the connected combo far enough, and the spring bars just swing into position. No pry bar needed. We do the same thing when we disconnect.

+1 to mjlrpod

grease the hitch/bar connection but not the bar to l bracket connection

making noise lets you know it is working properly

Vann

note-I also use a lithium spray lube on the trailer ball prior to hooking up