William Thompson

Change the fluid early and they still should have lubricity, and less metal in the fluid, by the change interval the fluid is worn out, and has little metal debris floating in it, and on the magnetic plug, 30-50k Acdelco Dexron VI transmission fluid, for the transfer case and the same stuff for the transmission, just a preference because its what came in the truck. Mine is a 14 Gmc sierra 4x4 Slt 5.3, Z71. I changed out the dexcool at about 145,000. Used the Acdelco concentrated and mixed 50/50 water, after flushing with distilled water. Probably could have done that sooner as it looked bad, and had some minor electrolysis. The front and rear diffs were easy on mine as well, I did the rear around 150,000 and the front sooner around 120-130,000. I replaced the brake fluid around 120,000 or so and it needed changing, it was very dark, when new fluid is almost clear.

Grass buildup when removing the condenser.

I have over 165,000 miles on my 5.3L 14 Sierra Z-71 4wd. No catch can. I have done routine maintenance on the truck myself. Regular oil changes with Mobile 1 extended life with the larger mobil 1 filter. Plugs and wire at 100,000 miles, flushed brake fluid, and did front and rear brake pads at 120,000 miles, put in a new condenser myself at 150,000 miles, it cracked, I believe due to parking on a slope with the front facing down, 5 hour job to fix. I had already put dye in the system to find leaks, because its easier to find a leak if the dye is already in the truck before it springs a leak. It was also a good time to blow out all the leaves and grass and bugs out of the radiator with a water hose. I did transfer case fluid and, front differential fluid at 110,000. Transmission fluid and filter at 90,000. I flushed the dexcool out at 145,000 and put new dexcool back in it. Just did rear differential and checked on brakes again but did not replace them at 164,000. I also replaced the left front seat actuator, and have the ventillated seat pads to replace drivers side heated and cooled seats.