Since my 2003 LS V8 is over 10 years old with nearly 100k miles (160k km) on the clock, I decided to finally change my transmission fluid and filter. It's well known that dropping the pan only yields about 5qt of fluid, which is barely half of the full system capacity. To change all of the fluid (well, as much as possible), a full fluid exchange needs to be performed. As I do not trust the local Ford dealers, nor any mechanic, I decided to DIY this, especially in order to avoid having the car hooked up to a machine that forces the fluid through the system. There is a great wealth of information online on how to DIY this, which will also apply to the LS as the basic procedure doesn't change. For that reason, this writeup is meant as a guideline-only, not a comprehensive DIY. Here are some of the resources I studied before tackling this project: http://www.explorerforum.com/forums/showthread.php?t=77507 http://www.tacomaworld.com/forum/2nd-gen-tacomas/68462-diy-full-flush-automatic-transmission.html http://www.toyotanation.com/forum/107-camry-solara-lounge/141381-diy-flush-transmission-fluid.html http://www.youtube.com/watch?v=MsdPAadc9fY LS Service Manual: http://deneau.info/ls/ (includes all the procedures for dropping the pan, torque values, etc - courtesy of Owlman) I did not take any pictures during the process.. who's got time for that? I unfortunately didn't. Do this at your own risk! It's not my fault if your transmission blows up :shifty: Parts List: 15qt Mercon V (only ended up using 12.5qt) - $100 (dealer) 1 pan gasket (mine had a slight leak in two areas, but I suspect the bolts were simply loose - why risk it?) - $25 (dealer) 1 Motorcraft FT-142 filter - $20 (RockAuto) 1 fluid pump - $12 (Local store) Hoses, fitting, tons towels, cardboard, gloves Total cost: $160 (rounded) Approx cost at dealer: $199 for pan drop, filter and gasket change $250 for flush Note: It has been mentioned on here that in order to fill the transmission via the fluid level check plug, the OTC 6604 fluid fill adapter is needed. I didn't feel like paying $10 for it, so I dug around and found out (courtesy of ExplorerForum.com) that a 1/8" NPT barb fitting will work perfectly. I used a 1/8" NPT to 1/4" Barb. Process: *Prior to starting, I went for a quick drive to warm up the fluid a little - I am not sure that it's necessary to do this. Part I: 1. Jack up the car/put it on a hoist and make it level. I did not have the luxury of having a lift, so 4 jack stands had to do. I only had about 14" of clearance to work under. 2. I first removed the inner level check plug to test fit my adapter, T30 torx in my case - about 2qt drained out 3. I then removed the large drain plug, 22mm wrench - another 2qt drained out 4. Drop the pan (reference service manual) - front of pan needs to be lowered first to clear the crossmember. Careful! I still had about a quart of fluid left in the pan, it might spill. Aside from the service manual instructions, I also had to bend the shift cable bracket slightly out of the way, and the Transmission Range connector got in the way too. 5. Clean the pan, magnet, all mating surfaces, and inspect gasket for damage - replace if necessary 6. Remove transmission filter - more fluid will drain out 7. Lubricate seals on new filter, and install - I almost didn't notice one of the old seals stayed in the valve body, careful 8. Re-install pan+gasket, torque (reference service manual), and re-fill with the same amount of fluid (5qt in my case) 9. Keep the hand pump attached to the pan. I clamped the hose however. Take a break Part II: 1. FIND A HELPER! 2. Remove the front engine splash guard to access the cooler lines 3. The upper line is the cooler->transmission line. You can verify by tracking the metal line back to the transmission, it's the top one 4. I loosened up the worm gear clamp, and pulled the rubber hose off the metal line 5. It's wise to plug the metal line, otherwise fluid will gush out once you start the engine 5. Direct the rubber hose into a measured out bucket/jug 6. Start the engine, drain 1qt 7. Add 1qt back to the pan 8. Repeat until clean fluid comes out - don't forget to add fluid after draining it! *It took me 12qt until I was satisfied with the color of the fluid coming through the return line. 9. Remove the plug from step 5 - old fluid will flow out out of the line! 10. Re-connect rubber hose and tighten clamp Part III: 1. Start car, shift through all gears, allowing each to engage, put back into Park once done 2. Remove the inner level check plug, or fill adapter - I still had my adapter connected in case the fluid was low 3. Allow the fluid to drain. When the fluid comes out as a thin stream or drip, the fluid is at the correct level. *In my case, nothing came out, so I shut the engine off, added 0.5qt, shifted through all gears for good measure, and re-checked the level. A little fluid rushed out, followed by a thin stream. 4. Re-install original fluid level indicator plug, check for leaks, re-install splash shield and you are done! 5. Reward yourself by going for a drive to enjoy all that hard work I noticed my transmission shifts more accurately now, especially the 1-2 shift. Overall shifts also seem smoother, and reverse engages quicker. The fluid I drained out was dark brown and smelled horrid, perhaps a little burned, I am not sure. The bad news is that I found a little bit of sludge on the inside of the pan, and even metal fragments Some dark, some gold in color. The magnet was relatively clean though. I wonder if this is related to the shudder I experienced last year? This is the pump I used, and my fitting (couldn't find a 1/8" NPT 1/4" Barb): And finally, the drained fluid, from the start to end of the process: My LS now has brand new fluids all around.