Hi,
I've been scouring the web for guides on replacing various fluids for my Xterra (differential, coolant, transmission, transfer case).

More than anything, I just need pictures of where various drain and input plugs are and brief how-to's.

I'm competent enough to change my engine oil and I was hoping to learn how do these other tasks too Instead of forking over $750 for a 30000 mile service. Any links, resources, or advice would be greatly appreciated.

Your owner's manual shows the various diagrams of components and their drain plug / fill plug locations / and fluid recommendations. (Front and rear diff's, transfer case). Don't refill these cases until the fluid runs out of the fill hole! Fill to just about a 1/4" from the bottom of the fill hole. Permatex makes an awesome thread sealant goop I like to use on the plugs.

Find the transmission pan, you'll see the drain plug. Refill through the dipstick tube. I make sure the ATF is at the right mark on the dipstick prior to the drain, then drain, measure how much old ATF comes out, then refill that amount. Do this once a year and your fine. There's lots of debate on performing a transmission flush at a shop with the various flush machines being used. The risk of clogs when reversing the flush could knock the slightest piece of debris and clog a one way valve or some other disaster in an automatic, supposedly. Their flush does get the remaining fluid exchanged out of the torque convertor. I just do the drain/refill thing 3 times over a week period to completely flush the whole transmission. Scared me enough researching this, that I stick to my yearly drains and refills. No filter on the automatics as well, so it's simple. Just use really good ATF, VALVOLINE! (I put on a Fram Sure Drain Plug instead of taking on and off the drain plug and risk stripping the shallow threads. Same for the oil drain plug.)

The owner's manual for my 2005 Xterra does not show any drain or fill plugs except for the Engine Oil. That's why I came online. I think they WANT you to go to the dealer for these things but the dealer prices are insane.

The 2005+ models do not use your typical Nissan Matic-D (Dexron-III/Mercon type) fluid, and the dipstick is bolted down to discourage anyone from attempting to do it themselves. You must use the new Matic-J fluid or you'll ruin the transmission.

The Diff's are easy. First open the filler plug (on top), then drain by opening the lower plug and clean off any metal filings from the magnetic plug. Refill to just below the filler-plug. Stick your index finger inside the plug and bend it (poor mans measuring for 1/4-1/2"). If you touch oil, you're fine. Use a 1/4" socket wrench to losen the plugs.

Always make sure you can open the filler plug before you open the drain plug. That way you don't drain the oil and then find later your filler plug is stripped of seized and you don't have any oil to drive to get it fixed.

If you're really interested in saving money, then buy a Nissan Electronic Service manual (xterraparts.com), or better yet, join a local Xterra club. You can always find someone who's done the work your interested in and most have "mod days" where people get together and wrench on their trucks and teach each other how to do it themselves. Plus you get to go out and wheel with a bunch of good people.