GM White Vent Cap Front Differential for Synthetic Fluid 2001-2003 GM 6.6L Duramax LB7 12479390

GM White Vent Cap Front Differential for Synthetic Fluid 2001-2003 GM 6.6L Duramax LB7 12479390

Early trucks ( 2001-2003) came from GM with a vent cap in the front diff that may not be compatible with synthetic fluid. In fact GM issued a TSB outlining that the vent cap should be replaced if using synthetic fluid. This is only needed if you do not already have the white cap.