Go here, I changed mine in May 22
Hey fellas, I’m new here and am trying to learn about the ZF transmission. I have a 2015 big horn with the 5.7L Hemi and 8HP70 transmission. I just turned 90,000 miles and have towed a small enclosed trailer occasionally during the past 20,000 miles. Ideally I would like to choose a...
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I recently changed my 2500 Diesel's transmission fluid and filter. Some auto parts stores don't keep very many transmission filter kits in stock, possibly since so many people choose to not change the fluid. I tow a mid-sized 5th wheel with mine, so I changed it around 50K. There was also a "return-line" filter inside my transmission that I had to purchase that filter separately (not in the filler/gasket kit). If you have never done this, don't rush, take your time and keep checking yourself; it is not that difficult. I make sure to have the wife's car on standby and set aside all day to "get it right". I also align the new gasket along the pan and count bolt holes before I begin to make sure I have the correct gasket. Loosen the bolts so that the pan lowers toward the back to drain. It will drain for a long time too. I also clean the pan real good with Brake-kleen and paint it with red "higher-temp" red paint before I put it back together. Don't forget to clean and replace the magnet. You can even write the mileage on the pan with a sharpie. Always pour the dirty ATF back into 1-gallon milk jugs so you know how much ATF came out. You can also see how "clean" it really is through the clear milk jugs. I also used the "best" brand-name ATF Advance Auto Parts had in stock. Plan to change it again at 90-100K too because you are really only changing about half of the fluid. I prefer to use Permatex non-hardening gasket sealer also, and don't skimp on sealant thickness on all four surfaces. Also tighten the pan bolts gradually, and not too tight to bend the pan. And, after driving, keep checking the level and top it off gradually over several days.