You have a few choices here, but all of them involve replacing the broken handles rather than trying to fix them. Your first option is to find one of the remaining Holden dealers out there and order genuine replacements. The second is to find a parts recycler (a wrecking yard as they were once known) and harvest a set of door handles from a wrecked Captiva.

The other option is to find an online seller with brand-new or second-hand replacements (lots of parts recyclers also have online stores). You can order them and have them delivered, usually within a few days if it’s an Australian-based seller. Just remember to specify the handles that incorporate the keyless-entry button.

For a start, you might find it’s neither of those things causing the noise. You may have a worn tyre, poor wheel alignment or a faulty brake, to name just a few possibilities. That said, both your suspects are likely contributors to this type of noise.

In any case, there’s a simple way to tell whether a noise is coming from the driveline (engine and transmission) or from one of the wheel bearings. Drive the car at whatever speed is necessary to make the noise appear. If it gets louder as you apply throttle, there’s a good chance it’s driveline related.

But now, with the car still making the offending noise, drop the transmission into neutral (where it’s safe to do so, of course) and let the vehicle coast. This takes all the stress off the driveline and the engine should return to idle. If the noise is still present, then you have a wheel bearing or other problem linked to the wheels, brakes or axles, but not the engine or gearbox.

Holden’s own service schedule for this model Captiva doesn’t specify a change interval for the differential oil. Instead, it recommends the oil be changed when required according to how the car is behaving. Which would suggest that your car is, indeed, ready for new differential oil.

As far as the scan goes, be sure not to confuse a sticking or non-engaging rear differential with the same behaviour from the centre differential. These are both technically differentials, but have vastly different roles to play. In the case of an electronically operated differential, the clutches can sometimes be replaced separately, but in any case, you need to go deep inside the differential, so while your mechanic is in there, have them check out the whole unit.