Can installing extreme pressure additive in rear end differential cause a problem?

Original service performed in Sept lists the following: -01482 Diff Fluid Syn 75W-140 -02632 Limited Slip Add / Extreme Press There is no mention of "XL-3" or anything called "Friction Modifier Additive" After replacing the failed gears the service ticket does include the "XL 3" Additive (no part number provided) along with the following: - 01482 Diff Fluid 75W-140 There is no mention of the 02632 Limited Slip Additive / Extreme Press. being installed after the replacement of the differential gears. I believe you are on to something. Thanks for the reply.

Not installing the friction modifier should not harm the gears. It would make the differential chatter on tight turns.

I tried looking up that part number and came up with nothing. What is it exactly?

The first go around there was no 01482 Diff Fluid 75W-140 added to the diff?

The first service ticket does include the 75W-140 but not the XL-3 additive. I drove for about 15K miles until the noise became more of an issue and returned to the dealer for investigation. After inspection, the dealer replaced the diff gears and rear bearings & seals - no questions asked. They provided me a rental while performing the repair and did not charge me a dime.

The original service ticket stated: "installed 02362: limited slip add / extreme pressure" but made no mention of "XL-3" additive. The corrective repair (just completed) included the "XL-3" additive and does not identify the "installed 02362: limited slip add / extreme pressure"