1998 Nissan Patrol Pricing and Specs

This mightn’t be too hard to figure out as the GU Patrol used a purely mechanical engagement system for the transfer case and four-wheel-drive system. Unlike newer designs with rotary knobs and electronic control, there’s really not to much to go wrong with the Patrol’s setup assuming it’s a selector problem. Make sure the selector rods are all connected properly and that they’re not binding or loose under the car.

However, if the lever is engaging and the front drive-shaft is not turning the front wheels, then you may have a hub problem. Free-wheeling hubs are great for saving fuel, but when they go wrong, it can often mean the drive doesn’t reach the front wheels. At that point, you have a bigger job on your hands. The same symptoms could also be a result of a broken front differential which is not sending the drive out to the front wheels. Finally, the transfer-case itself may be at fault. If it’s not sending the drive forward, there’s no way the vehicle will achieve four-wheel-drive.

Also, to maximise your chances of engaging four-wheel-drive, make sure the vehicle is stationary at the time and the transmission is in neutral. In fact, this is essential for moving between two and four-wheel-drive in many types of off-roader.

You could be looking at something internally wrong with the transmission, but the clue that this might be something simpler is in the way the engine will start in Reverse which, of course, it shouldn’t (for safety reasons). The suspicion would be that the relationship between the selector (inside the cabin) and the actual gearbox is somehow out of synch. So when the selector is telling you the car is in Reverse, it’s actually in Park or Neutral, which is why the engine will start.

That might also explain why the car won’t select fourth gear; the position that actually coincides with Drive (or fourth gear) looks – from inside the cabin – to be the Neutral position. So, to check this, put the car in what looks like Neutral and, in a safe place, see if it moves when you give it some throttle.

Failing that, you’ve got two separate problems. The first is the inability to select fourth gear (which could be a hundred things) and a failure of the safety switch which is allowing the engine to start in Reverse.

It's frustrating when a dealer misdiagnoses a problem, and then charges you for the work they've done, even though it hasn't fixed the so-called problem. In this case, from what you have told us, there really isn't a problem. You say you are able to start the car first time, every time, by simply waiting a second or so longer, it was only the dealer that claimed it was hard to start. I wouldn't trust the dealer and would take the car to someone else if you feel you need to have it checked further, in this case one who specialises in diesels.