Decided to change all fluids and changed brake pads of my 2013 GTS before I do a few track days in the next few weeks. It has about 4000 miles and 1 track day on it. (I drive it more than it sounds, purchased it "new" about 8 months ago).

I noticed some people asking for an easier way to fill transmission and diff fluids on multiple threads (none of the threads I found were Gen 5 specific as I couldn't find any), please see below picture for alternative way. (If this is a known method, feel free to ignore)

A couple things I noticed: (No, I didn't collect any oil to be analyzed, only my observations)

- Diff fluid had some particles in it(Still less than my other vehicles), also it was very runny comparing to new diff fluid. Used Amsoil severe gear 75w-140 until it started to leak out.
- Transmission fluid looked fine, didn't find any particles. Used about 3.5 quarts of Amsoil ATF.
- Stock brake pads were half gone and rotor thickness was about 31.4 mm. I read the min is 30 and it starts with 32 so I am hoping rotors will be fine next 2-3 track days.
- Engine oil dipstick is the worst I have ever used. I added about 10.8 quarts and after checking it 10 times, I am still not sure if I overfilled or if it needs more I went with 0-40w Mobil 1 European formula as I couldn't get the stock fluid locally. I did drain the oil for about 45 mins as I saw that was recommended.
- You need T30 and T40 for belly pan. (I had 3 different torx kits, none of them had T40 so I took trip to HD)
- I did have one screw up while I was bleeding the brake fluid. I wanted to get all the old fluid out and I was peeking at the reservoir from RR and it seemed like it still had fluid. I didn't notice baffling kept fluid on windshield side but it had actually run out of fluid. Ended up with air in the system, it took about a bottle of Motul to get all the air out. I am still not sure if any could be remaining in ABS system. : ( I couldn't do any real test yet but the brake works but the pedal is not as stiff as I would like. I am hoping it is because the pads are not bedded in yet.

Tranny\diff fill method:
Simply fill the container and lift it higher than transmission\diff until it all flows down. ( I got lazy and held the container myself instead of installing a hook on the ceiling, turned out to be more tiring, especially with diff fluid)
ViperTransmissionFluidChange.jpg

Stock brake pads vs New (I went with Raybestos ST47 fronts and ST45 rear)
ViperBrakePads.jpg