When servicing my 2011 VE Commodore SV6 at 60,000 km my dealer wanted to charge me extra for changing the brake fluid when I have a capped service agreement with them? The service person also wanted me to do the power steering fluid, something I have never come across before. I did not realise my error of not insisting the brakes be done as part of the service until sometime later when I was reading my handbook. I am also keen on changing the automatic fluid, but I understand the cost on the 6-speed is quite high. True? If so, at what mileage would you recommend it be done? Lastly, I have an intermittent noise from the diff, the service people said they could not find it during road testing and I didn't really expect them to find it. Can I, as a precaution, change the diff oil to a better type and maybe gain longevity? I do not want to jeopardize my warranty.
It's always a good idea to read the fine print so you know what it and what isn't included in the servicing schedule. I would expect that the brake fluid would be changed as a regular part of the servicing and shouldn't be an extra cost. Doing the power steering fluid is being over-serviced. Draining the transmission oil and replacing it isn't hugely expensive, but changing the oil, which includes draining the torque convertor, is more expensive and amounts pretty much to a full service. It's still worth doing and 100,000 km is probably a suitable point in time to do it. As for your diff noise, you could try asking your dealer people to go for a ride with you to assess it. Changing the diff oil can help quieten the noise.