Originally Posted by JungleJim
The Toyota OEM reciever is not class III.
But please be aware that it is indeed a Class II hitch not designed to be used as a WDH.
On my OEM Toyota hitch, there is no indication of capacity. Since it is supplied by Toyota they report the vehicle's capacity when using that hitch (as with the RAV4 material quoted above); we don't know what the hitch manufacturer thinks the rating class should be. The only information is that the hitch is at least Class 2, and the combination with the RAV4 does not exceed Class 2.
Similarly, since Toyota as both vehicle manufacturer and hitch supplier does not endorse WD use for the OEM RAV4 receiver, the hitch is not to be used with WD. That doesn't mean that the hitch itself is unsuitable, or that the aftermarket hitches are suitable... we just don't know, so the best information we have is Toyota's rating (Class 2, 350 lb tongue weight
, weight-carrying only).
The SAE standard for hitches (J684) does not define the receiver box size
; indeed, it doesn't even mention the concept of a receiver-style configuration. One could build a Class 3 hitch meeting the standard with a 1.25" box, or any other size, or without a receiver at all; similarly, one could build a receiver hitch with the 2.5" square box that is now available, and meet only Class 1 capacity if there were some other weak link in the design.
Similarly, SAE J684 doesn't define the use of weight distribution systems
. Class 2 does not mean no WD; Class 3 doesn't mean WD is allowed... WD is just irrelevant to the standard and the classes. Of course, there is a common industry practice of offering WD only in 2" and larger receivers, and using 2" receivers for Class 3 and 4, while using 1.25 receivers for Class 1 and 2, but it is not governed by any standard.