I installed a mag-hytec diff cover and added a synthetic oil and felt a grinding going on in the diff. I drained and added another prominent oil and still had the slight grinding while turning. The manual states that no additive is necessary. I was at a local rear end shop dropping off a third member for my Charger and inquired about the truck while I was there. They immediately handed me a small bottle of additive and said they know what the manual says but this is what you need. I added this and the grinding was gone within a few miles. They also told me that they get at least two trucks a week from different manufacturers doing warranty work on the diffs. There opinion is that synthetic oils are great for bearings but they are not pleased with them in diffs.
I didn't list the oils I used because I didn't want to start an oil war.
Steve
I didn't list the oils I used because I didn't want to start an oil war.

Steve
Last edited: