Hi Gents,
To be frank, I think its just "Nissan being Nissan". There are members of the Y62 FB group using Nissan towbars who have been using WDH for several years without an issue. From what I have picked up in that regard, there does not appear to be any structural issue with the factory towbar that would preclude the use of a WDH.
Note that Nissan's recommendation re: WDH usage is "across the board" - they do not recommend the use of a WDH on ANY of their fleet of vehicles. My personal suspicion is that this harks back to a couple of towbar failures on pathfinders (where the use of a WDH apparently ripped the entire towbar assembly out of the back of the chassis rails), however I must make it clear this is only my personal thoughts. The D40 Navara (which has chassis similarities to the Pathfinder) was the subject of a recall due to cracking of the chassis where an original equipment towbar was fitted. It has been suggested by others that the original equipment towbar design on the pathfinder was not suitable for purpose, and that when a WDH was added - the thing basically tore itself apart. Google is your friend if you want to know more about those failures. There are many pathfinder owners out there using Hayman Reese towbars AND a WDH - and who have been towing for years without a hint of trouble. The HR towbar design is substantially different to the Nissan original equipment design though,,,
Prior to the issue with Pathfinders, I am not aware of a negative recommendation from Nissan re: WDH's being used on their vehicles.
It is interesting to note that Nissan USA have recently started selling what we know as the Y62 - they call it "Armada". (Previous versions of the Armada were no relation to the Patrol.) Nissan USA advertise a WDH as an original equipment accessory. (
https://www.nissanusa.com/suvs/armada/versions-specs/version.platinum.html)
Personally I don't use a WDH - I have my own opinions about the individual circumstances surrounding each rig, and determining the need for ANY add-on based on individual circumstances. However should I require one, I would have no hesitation in using one on the Y62 with the original equipment towbar. It, and the chassis is mounts to, are 'substantial' to say the least.
Okay, if you've stuck with me this far I presume you're interested
The Nissan spec sheet says for the previous (Y61) Patrol:
"
Nissan is not able to make any recommendation on the use or suitability of load-levelling or weight distribution devices to be fitted to the vehicle."
On the NP300 Navara spec sheet they state:
"
Nissan is not able to make any recommendation on the use or suitability of load-levelling or weight distribution devices to be fitted to the vehicle."
On the Y62 spec sheet they state:
"
Nissan does not recommend the fitting of load levelling or weight distribution devices when used with a Nissan Genuine towbar."
I find their use of wording very interesting. Note that nowhere do they say you should not use one - just that they do not recommend it...
Anyway, hope this helps even though I know its not a definitive answer. For what its worth, I will (eventually) fit airbags to the back-end of my Y62 because I would like a small amount of ride-levelling (as opposed to 'weight distribution'). With my 22.68-1 hooked up, loaded for bear, my Y62 measures approx. 10mm 'lift' at the front axle, 30mm 'sag' at the rear axle. Standing back and looking from a distance, it LOOKS a whole lot more than that but the tape measure doesn't lie. For me, that is well within the scope of 'normal loading' and does not necessitate a WDH.
Further note: a Y62 ALWAYS looks like it is low in the arse end. That is just the look of the thing. Whereas a 200 series for instance always looks like it is arse up in the air and sagged front suspension.