Mitsubishi Triton 2006 Problems

Mitsubishi’s manual gearboxes from around this time (and earlier) were some of the noisiest around. But usually it wasn’t anything to be concerned about. Bearing rumble and some clutch bearing noise were pretty much par for the course, but your problem sounds more like it’s associated with the gearbox’s synchromesh rings. These rings are designed to allow the gearbox to slip between ratios smoothly and silently, and any crunching noises during shifts can often be traced to worn synchromesh parts.

The good news is you won’t harm the transmission by continuing to drive it, particularly if you’re careful and take your time with the shifts you know are most likely to create a crunch. If you can live with that, fine. If not, the gearbox will need to be removed from the car and rebuilt. That will be neither cheap nor simple.

I would be looking at the fuel supply, the filters, fuel pump, and the fuel itself. If the performance generally has dropped off I would also be looking at the turbocharger.

I would agree with the dealer's diagnosis of carbon build-up and cleaning it will probably fix it.

They’re not required on utes. Triton GLX-Rs have one on centre of tailgate and have had since CR launch in 2006, but GLXs don't have one.

Unless you need a vehicle capable of driving over rough or slippery ground, I would buy a 2WD diesel ute. It will be more economical than a 4WD and will tow your trailer without problems. Your budget will get you an upmarket ute. Look at the Toyota Hilux or new Mitsubishi Triton. Also, there are good deals available on the Mazda Bravo and Ford Courier for much less. For little more than $20,000 you'll get a 2WD diesel with a tray and toolbox.

Like you, I read about these systems and the claims their designers make for them, but my experience is that they rarely, if ever, work out in real life. If they really did work, why aren't they taken up by carmakers? The fact that they aren't seems to answer your question.