My 98 Prado has been an extremely reliable vehicle.  Mind you , since new I have serviced it every 5,000km.  However the other day I finally got my hydrogen generator installed and running and I noticed two bad noises coming from the centre of the car.  I tried everything to narrow these noises down.  One was a sort of continual rumbling on acceleration and deceleration, while the other was a high pitched screaching, something reminiscent of running a finger nail down a chalk board.

I had people running beside the vehicle trying to work out where it was coming from and by that night I had convinced myself that it was a gearbox bearing.  Next day I took it to work and got 2 of the techs (at different times) to diagnose the problem.

Both techs came up with the same theory – a dry universal joint.  A quick re-grease of all joints and the problem was fixed.  I had done a couple of big river crossings just after my last service, so it’s amazing how quick the grease can wash out.

Moral of the story, have another quick service done after decent river crossings.

Tip:

Radiator Fan<br> While under the hood spraying water repellent, check to see what type of radiator fan is fitted. Most 4x4 's these days have the viscous coupling type, which means that when the engine is cool enough the fan doesn't spin at full speed. With the engine off, try and turn the fan. If it turns easily, you will probably get away without having to take off the fan belt. If it doesn't turn easily or yours is the fixed type, then you should remove the fan belt, If you don't and water enters the engine bay, the fan may act as a propeller, bend forward and cut a nice round hole through your radiator. It's certainly one problem you don't want to discover once you have completed the crossing. Even if it doesn't affect your radiator, you still do not want water being sprayed around, especially in a petrol 4x4.