4WD drive train question
I'm the original owner of a 2007 2500HD Classic 4WD with 65K miles. All other maintenance has been kept up to date, but I haven't replaced the differential and transfer case oil. Should this be done soon? If so, should I use a synthetic for longevity?
2007 2500HD Classic 4WD LBZ 65K miles
Last edited by OkDually; 12-19-2019 at 01:16 PM.
Reason: prefix adj/sig