I just finished replacing all my fluids on my truck at approx 65,000 miles. This is my general experience and recommendations. The 2014 is the first year of the latest generation of Tundras. My experience maybe slightly different and I followed the 2015 Toyota Service manual. I used Sprayway Glass cleaner to clean up my drain pan between oils and transmission fluid. It has two strong alchols that evaporate and will not contaminate your fluids. It is also the best glass cleaner there is on the market. You can find it most anywhere cheap. Walmart has it for around $2 a can.
1. Rear differential
All of the existing videos or DIY I reviewed for the rear differential are basically the same and accurate. The only difference would be that most recommend or used 75-90 gear oil. Toyota recommends 75-85 GL5 fluid. That is what I choose to use. I used Red Line synthetic. I've attached a picture of everything I used. You need 4 quarts for the rear. You'll have some left over. Probably 1/2 to 3/4 a quart. The oil that came out was very dirty. The worst of anything I changed. Definitely need to change this oil.
2. Transfer case
14+ now have a Borg Warner transfer case. I didn't find a DIY that deals specfically with this version but there are many threads on what type of oil to use. I used Ravenol J1C1003. You'll need 2 Liter bottles. This biggest difference in servicing the this transfer case is the fact the plugs have pipe threads and need "plumber's dope". I didn't find anything in the Service manual on this except to completely replace the "filler plug". I used TFE oil resistent slow set paste on the back threads just like what was on the plugs to begin with and torqued to spec. This basically a sealer that also acts as an anti sieze..... I may not change this oil again. Even though it is rather cheap and easy to do. The oil that came out was vritually clear. It looked almost brand new. I use my 4 wheel every once in a while. If do the same, you might not need to change this oil.
3. Front differential
This was probabily the hardest oil to change if you decide to work from under the vehicle. I decided to remove the left front tire. I recommend you do the same. When you do, you'll be able to see the top filler plug and use a long extension to remove it. Just make sure to level the wheel on the jack and use jack stands. This is important to get the proper fill level. It also aids when changing the transmission fluid. You can see the filler plug better and insert the fill hose. You don't need to buy a pump to fill the differential. I used a 3/8 ID tube rigged to my oil bottles. The drained oil was dirty but not as bad as the rear. Only holds a little over 2 quarts. Lower capacity than the rear. You should change this fluid.
4. Tranmission fluid.
This is the main reason I decided to record my experience here. The DIYs are different than the 2015 Service manual. There are 4 transmission models detailed in the Service Manual and all of them have the exact same procedure to replace the transmission fluid. I'm going to break the pages out of the service manual and add them to this thread for your review.
I bought the largest funnel I could find at Harbor Freight because I wanted a clean funnel for just this process. Make sure it clean you don't want any dirt or fibers going into your transmission. I did some mechanic work when I much younger and most all new tranny builds fail due to contaminates in the rebuild process. I bought 1/2 inch ID hose and added 2.5 foot on the end of a the new funnel. This fits tight into the fill plug hole. So tight that I didn't even bother removing the funnel and drain hose during the replacement process. I didn't have any leaks from the fill hole.
You want to start this process when the tranmission is cold. Basically, you will drain and fill the pan three times to completely replace the fluid. The new fluid is pulled up from the pan and through the system as old fluid is returned to the pan each time. I measured each and every step and here is what I got. The first drain was 3.75 quarts. I then added back the drain plug and filled till I got a trickle. About 1.75 quarts. Then I screwed in the overflow plug and put the required 2.2 quarts back in. This is bascially right at 4 quarts. I then started the truck and moved the gear selector throught the gears. Let it then run the required 30 seconds and cut off the engine. Waited for the oil to settle into the pan and then drained again. Got 4 quarts this time. I put all the plugs back in and added 4 quarts back. I repeated the process of starting the truck, move the gear selector, and wait 30 seconds for the truck to run. Drain one last time and got 4 quarts. Added all the plugs back and filled with 4 quarts. One last time through the gear selector and 30 second wait. I then performed the fluid fill check process. You use a paper clip and bridge pins 4 and 13 on the ODB2 and go through the process. See attachment. Ultimately, I drained almost a 1/2 quart from the tranny. Fluid replaced. I bought 13 quarts but only used 12.
I did not perform the reset of the "ATF THERMAL DEGRADATION ESTIMATE RESET" detailed in the Service Manual. I don't know that it makes any difference and I haven't seen any DYI that detail performing this process.
Here is what I used and what the current prices are.
(7) 50104 RED LINE OIL GEAR OIL $12.07 per quart. $84.49
(2) Ravenol J1C1003 $15.96 per liter $31.92
(1) Harvey's TFE Paste. Here is a link but I found a small tube at my local hardware store for like $3.00
(13) quarts AISIN WS tranmission fluid. These are AISIN transmissions. $5.79 per quart. $75.27
(2) Transmission pan crush washers.
(1) pack GENUINE TOYOTA GASKET KIT FOR TRANSFER AND DIFFERENTIAL SERVICE $11.74
Hope this helps and I'm defintely open to criticism
Having done this once, I could probably do all of this in about 2 hours taking my time. The first time, it took me much longer.....
5. Coolant Replacement.
I've added the pages from the Service Manual. I'll add my experience after I do it. Need 3 gallons. Using Aisin fluid from Rock Auto. Good Price $51 including shipping for all 3 gallons. I don't know for sure but I'd bet the water pumps are AISIN on the 5.7. Little maint to make the water pump last as long as possible.
Might as well do this when you take the driver's side tire off to do the front axle oil drain and fill. Have to take off the front tire to get to the block drain. The book says it takes 13 some odd quarts. I bought 3 gallons and got about 3 gallons out in my drain. Block drain is hard to get to. Takes patience and a short 10mm socket, short 1/4 extension and a short ratchet. Don't over tighten. Only specs to be 10ft lbs of torque. Pour replacement fluid in slow to let the system burp as it fills up. If you do, then you won't have to add a bunch a fluid after. The fluid looked "reder" than I expected. I'm glad I changed it. Not much money to keep everything lubricated well. I'm now done with my 5 year fluid replacement. On a side note, most of the replacement fluid I've seen rates itself at 5 year or 150,000 miles. I believe Toyota has it wrong on this one.