Mountain biking by nature is hard on its tools. The freehub body is no exception. After a few good hard years, it's not uncommon to see them wear out. Thankfully, we've got replacement freehub bodies right here. They're all the Hyperglide interface, not XD, so they will fit Shimano 9 - 11-speed cassettes, and SRAM 9 - 10-speed cassettes. You just need to determine which freehub style your Mavic hubs are, be it TS-2, FTS-X, or ITS-4.
Replacement freehub body for Mavic mountain bike hubs