Optimum Rev Range Query - Hilux LN106 (3L engine)

David.

Having driven a number of these vehicles, and done transmission repairs on a few, I would suggest that your current rev range would not be too far off the mark, however I would recommend that you do NOT regularly drive the vehicle in 5th gear below 2000rpm, or 80 kph, whichever is the highest of these 2 speeds.

As 5th gear, being an over drive gear and also containing the smallest gear in the transmission, tends to suffer from the torsional fluctuations that naturally occur with low engine speed. I have seen a number of 5th gears with broken teeth in these vehicles that were regularly driven below 80kph in 5th.

Regards
Athol

David.
Besides the driving style, if you want decent life from the engine make sure you use a good quality, well known brand of engine oil and change it when it is too greatly discoloured from carbon which has escaped past the rings. This is use and load dependent, not on km's necessarily. GOOD oil seal the rings better , = more power and economy a bit, and the better ring sealing keeps the oil cleaner for longer. Junk oil promoted at Motor Houses isn't necessarily a good oil.
If engine well used, a possible retiming/check of the injector pump will see more power than at present, It does make a difference if not correct. Correct "even" valve clearances is a sensible thing to consider, ie, a tune up of engine.

Regarding rev-range to operate your car, listen to the car and feel how it is responding, as this will give you the most important feedback to whether you're driving it as intended or not. I'd have thought an older-tech diesel should be able to pull pretty well just above idle, unless you're really sticking the boot in.

If the car is not responding by accelerating when required, this indicates you are outside the useful rev-range. If revs are too low, the car will start to grumble/rumble and/or shudder and you won't feel the engine pulling - downshift. If revs are too high, you won't feel it pulling (particularly with an older tech diesel engine - you'll probably feel it pulling as you accelerate up until a particular engine speed and going beyond this you'll feel the power drop off and it will feel like all it's doing is making noise).

Over time, as you listen to the car and feel how it responds in different situations, you'll get to know what works and what doesn't, and this will be far more useful than watching your tacho' and memorising gear-shift positions.

And don't labour (ie. heavy acceleration, powering up a big hill, etc.) in fifth gear with is only an overdrive (ie. smaller gears, mounted off to the side of the main 'straight-through' gears, and therefore not as strong). I've heard quite a few people bragging about how their diesel car can pull up almost any hill in fifth gear, and only the next sentence they're telling you that fifth gear is noisy... (they've probably over-loaded the bearings which are now 'whining' in protest!).

So do these hiluxes have gear box issues are they to light for the vehicle ? I've has several diesel over the yrs and never had issues from loading up the box and letting the torque do it's job that's how you drive a diesel and you change gears less than a petrol but yes don't get to the point where your labouring the engine. When your towing then you use the revs as well as torque to keep it rolling you can find the sweet spot and don't ever be afraid to rev a diesel up to the red line when needed even if you have to hold it there climbing hills or sand driving etc they love it don't let any one tell you it is no good for them.