FWIW, i put Amsoil in my front and rear differential and in my transfer case about 110k miles ago. No known issues. I also use Amsoil in my ZF8-70 transmission. No Issues there. I am driving a 2014 Ram 1500 with the 5.7 hemi, 216,000 miles. I should tell you that I had head gasket leaks on the passenger side. I took it to a mechanic friend. He heard things I did not hear. He heard sounds on the drivers side also. To abbreviate this story some, when it was finished, he had replaced the cam and on cylinders 5 and 7 he found stuck lifters and cam lobes that were rounded. He said the old drain holes were too small and so the valves and lifters were running dry. I also had a Diablo tuner that made a noticeable difference when I re-tuned the engine. To shorten this story,further, before it was over, he reamed the oil passages a few thousands larger, put in a new performance cam, replaced some lifters and valves, of course he fixed the exhaust leaks, and he re-tuned my Diablo tuner with some new software. My engine has greater performance now, the auto shut-off of 4 cylinders for fuel economy now run 100% of the time, my fuel economy is better, and I change the Amsoil engine oil every 5,000 miles per the cam manufacturers instructions. My brother has a 2019 Ford F-150 with the Coyote V-8 in it, and my truck is faster, and quieter than his truck. I do not use oil, and it seems to run great!