Had a couple of lightly used D40 Navaras at work as mentioned in a previous post, had nothing but troubles with them, same issues that you will see documented on many of the complaints websites. These include: Woefully inadequate brakes that have the ABS constantly cutting in, injectors cacked themselves before they even got to 70000kms, went into limp home mode on several occasions without any real reason, ABS sensor lines got severed by stones flicked up by front wheels due to poor location of lines running over the front of the rear axle, bonnet catch snapped off due to flexing of body on inadequately strengthened chassis - whole bonnet required replacement as the bonnet catch loop is welded to the bonnet skin, not bolted on. Also for the same reason, cracks started to appear on the inside of the front guards and firewall due to body flexing too much on chassis. All the cracks, brake sensor lines and bonnet were replaced or repaired under warranty, but cracks re-emerged in the same areas around the repair welds within a few weeks.
You only have to look at the thickness of the chassis rails on the Navara, and compare them to say the patrol, they are weeny, resulting in too much flexing for such a heavy vehicle. Other issues include early wear to the clutch (very common issue), poor low down torque from the 2.5, making pulling any towed load a chore from standstill, also an issue in low range, off-roading.
Now these vehicles were used mainly to ferry people back and forth long distances on bitumen and well made dirt roads, barely any low range off road work. On the upside, they were comfortable for long distance driving, had good pull from the 2.5 for overtaking when at up to speed, and had plenty of room. The original 2.5 was a poor choice for such a large vehicle, and I'm really not a fan of common rail diesels, they are very susceptible to the smallest bit of crap or moisture in the fuel, enough to stop you dead in your tracks - not something you want in remote areas.
We also had two 4.2 litre patrol coil cab chassis utes, they were unstoppable, even a bit of moisture wouldn't faze them, very well built. If you buy the coil cab patrols, it is advisable to reinforce the rear spring mounts with bracing, as they tend to sag with any significant weight it the back.
The other Nissan we had was a Navara D22, that was 100% tougher ute than the D40, the 3.0 litre diesel never had any issues other than a fuel tank for of water courtesy of the Marla Roadhouse, had to drive about 80kms in limp home mode from a station to Kulgera Roadhouse on the Fink River road in limp home mode -not much fun! Nissan towed it back to Alice Springs for a full fuel system cleanout.
Bottom line is if you own a D40, particularly with the 2.5, keep an eye out for cracks developing on the inside of the guards in the engine bay, and bonnet latch loop where it is welded to the bonnet skin. I am not a big fan of common rail diesels, they are very problematic when it comes to reliability, all for the sake of complying with European emmissions - not something I really give a hoot about stuck broken down out the middle of nowhere.
On another note, Prados are also susceptible to stress cracks in the firewall, so something else to watch out for.
