DOES ONLY WHEN SPEED UP OR SLOW DOWN
HAVE A NOISE IN REAR DIFFERENTIAL,ADDED QUIET LUBRICANT, BUT STILL WHINING on 2005 Chevrolet Silverado 1500
POSS BEARING OR GEAR NOISE, HAVE AN INSP DONE
3 more answers , 1 more comment
okay...so have a shop check your truck
Diffrential bearings are most likely worn causing gear mesh to be out of spec. Recommend that you have a shop that is experienced with differential repairs check it for you. This should be done sooner than later before damage is done to gears to keep cost in check.
maybe your differential needs to be replaced
YOU MEAN REPLACE THE INTERIOR PARTS?