Axle Center Section
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Chunk is slang for 3rd member or center section of a rear axle housing. It is usually limited to the removable section of a housing found on a Ford 9" or Mopar 8 3/4" rear axle assembly. The center section houses the ring and pinion gear, which is attached to the spool, locker, or differential. Having this chunk being removable make for much quicker gear changes than in the non-removable center sections of the Dana 60 and Chevy 8-bolt axle housings.
