Hitch-mounted Cargo Box

The enclosed carrier is nice, but at 76 lbs empty it is already close to the maximum weight I would dare hang out there behind the hitch, before putting anything in it. I might want to increase the margin of safety by getting one of the lighter-weight carriers (some shown here) and, if weather threatens, add a cargo bag or wrap a tarp around the stuff.

The NHW20 Prius seems to have an interesting bracket on the underbody that's about perfectly placed for modding a hitch to better resist twisting under tongue weight. That might help.

-Chap

 

Some people are already doing this.
M\I recommend the Curt hitch, but it is only 1 1/4"
The Coastal Tech hitch comes in a 2" version but due to the way its is made you have to weld in another brace from the hitch to some point under the car (I forget where there are pictures on the site somewhere) or the hitch WILL bend, and badly.

The Curt doe not seem to have this issue with up to about 100lbs total.

 

I would have reservations using something at or near max for more than occasionally. You could try bracing, but it may have implications as yet unthought of.

If you have storage for it when not in use, I would recommend a small trailer. It would cause much less heartburn over the long haul (if you'll pardon the pun...).

 

I would not recommend it. The car is too low for such a hitch-mounted carrier, unless you can be exceedingly careful about parking lots. The extended bar beneath the cargo carrier will constantly be bottoming out if the lot has a grade to enter/exit, and this would probably damage your hitch, car, and the carrier.

We have a car with considerably higher ground clearance and this is a big problem for our hitch-mounted bike rack. I would never again buy a hitch-mounted item that extends horizontally more than two or three inches.

 

I'm a bit leery of trying the obvious experiment to see whether the first failure mode from excessive tongue load is bending of the hitch, or kinking of the unibody "frame" channels at the hitch attachment points....

-Chap

 

I bought this for a bike carrier:


It's great for dirty things like garbage/recycling, firewood, etc.

Theres no noticeable change in fuel economy, because the load is carried in the turbulent air behind the car.

I've jumped up and down on it, overloaded it, no problems. It's been hit by numerous other vehicles in parking lots and gas stations, with no damage to the car or the rack.

I do scrape the ground with in driveways and such; but that doesn't hurt anything, it just scratches up the bottom of the carrier and makes a loud embarassing noise.

BTW: Curt 1 1/4" hitch, Aluminum rack from JCWhitney about $300 altogether.

 

Yup, with the Curt hitch, a cargo carrier is possible. I wouldn't hang anything more heavy than a feather (small bird also!) on the Coastal hitch after seeing all the problems with them bending and rusting.

Go for a cargo carrier that has these attributes:

- lowest weight you can find (generally AL not steel)
- look for one with a built in rise of several inches

You'll be a happy camper!

... Brad

 

It's useful for strapping down lightweight things like sleeping bags in a sealed plastic bin. Mostly air, so it fits bulk, not weight. I'd never put the ice chest (full) on it!

That third attachment referred to mounts to what is in fact the rear center jacking point, so you may have a problem with a garage trying to lift the rear for service.

 

I am in the process of adding some extra support to the hitch/rear carrier for my 04 Prius. I am going to be using the car for carrying a 100lb lawn mower. My plan is to attach some steel supports from many areas on the body. It's not very thick, but if I spread the load out over 6-10 different areas/bolts, each one should be good for 20lbs or so, and therefore add about 150lbs of tongue support. I just installed the Curt hitch, which is clearly overbuilt. I just wish Toyota had the frame rails extend further towards the bumper. The bumper itself seems to not flex at it's mounting point with over 100lbs of force. It's held to the ends of the frame rails with what looks like 4 bolts that are about 1/4" thick.

Currently my concern is the stress on the 2 rearward bolts holding the hitch on. They are grade 9, but there is a lot of stress on them when I go over those speed humps they have all over my city (Austin). And of course the frame rails, which actually have this extra mounting plate apparently spot welded to them. That's what the tow hooks bolt into.


Pic attached is not my car, but to show what I plan to do. The other support could be putting anchors up on the body near the top of brake lights. For the heavy loads, use tie downs here, to the most rearward point on your rack to further reduce the tongue weight via a triangle.

 

random trailer hitch installations