The coolant change had nothing to do with the cross-contamination issue, which is caused by a seal failure in the radiator's integral cooler. Both of Nissan's coolants are made by Pentosin: Nissan green is Pentosin Pentafrost A2 and comes as a concentrate, while Nissan blue is Pentafrost A3 and comes in as a pre-mix. Both are long-life coolants, but, blue is, for lack of a better term, a "longer life" coolant. Nissan green is recommended to be serviced at 90,000 miles and then at 60,000 miles, thereafter. Nissan blue's service interval is at 150,000 miles. While the two are compatible, one has to remember that any green coolant mixed in with the blue coolant will shorten the blue's 150,000 miles service interval accordingly. Nissan started incorporating blue coolant in it's vehicles in 2010. Pentosin anti-freeze can be purchased from Rockauto.com, Amazon and found on Ebay. With a 2009, one might also consider replacing the radiator and the coolant, if the radiator is the factory-installed unit and the truck has an automatic transmission.
Engine oil and filter are always highly debated as everybody has their own preference. I've always stuck with genuine Nissan oil filters, but go with Purolator Pure One filters in a pinch. Purolator makes a large number of the filters on the market, including Bosch, Motorcraft, Pronto and many others. AC Delco makes an excellent filter, as does K&N, Wix, Mahle. I've never been a big fan of STP filters nor Fram, due to their construction...but, I've never ran into any problems with either of them. Engine oil is equally debatable. Most will agree, including myself, that 5W30, as recommended by Nissan, is the best to stick with. I know on some of the newer Nissans, they are calling for 0W20 synthetic, but, also go on to say that 5W30 conventional can be used as an alternative and will not void warranty. Blackstone Labs, who does oil analyzing, states that their employees all use conventional oil, which says something. I don't think there is any argument that synthetic oil is better than conventional oil, but, is it really needed in or provide any real benefits to the majority of the vehicles on the road? I think the bottom line is that oil quality these days is very good and any API certified 5W30 will work just fine provided that is is serviced at the proper intervals. Personally, I use Walmart's Supertech 5W30 full-synthetic at 7500 mile intervals. I had a sample tested by Blackstone Labs (when my engine reached 150,000 miles) and they recommended extended my intervals to 9500 miles.
I do a drain and fill of the automatic transmission fluid and transfer case fluid at 50,000 mile intervals, using Valvoline Maxlife ATF. Castrol Transmax Multi-import ATF is also a good choice and both are a lot less expensive than NissanMatic "J" or "S" ATF and work just as well. Most synthetic ATF's are JASO-A1 compliant and will work fine in the Nissan 5-speed, rear-drive automatic transmission; just make sure it says it is recommended for use in NissanMatic "S" or "J" applications.
I service the front and rear diffs every 60,000 miles using synthetic 75W90, either Mobil One or Supertech.
The engine oil drain plug and transmission drain plug use copper crush washers, Nissan #11026-01M02, which you can buy in bulk on Ebay in bags of 5, 10, 20, 50, etc.
The transfer case and differential fill and drain plugs use aluminum crush washers, Nissan #11026-4N200.
Don't forget your cabin filters behind the glove box!
