Had my 4x4 truck in for a oil change and 21 point inspection on Nov 27, 2009. 3 weeks later I had a metal grinding noice and my 4x4 failed when I engaged it. I immediately went to my local GM dealer and it was discovered that my front differential was completely dry of oil. This caused the differential to lock up and put enough strain on the transfer case to damage it as well. I immediately went to Pro Lube and informed them of the problem...they didnt care. I spent $2925 to fix my truck and returned to Pro Lube about this. Now the were saying... read full review »