Hello,

Here is the problem that I am having, I hope someone can help. I have an 06 GMC Sierra 1500 2WD with a 4.8L not sure what the Trans code is but I know its an Auto(I'm SMRT like that). this is what it's doing, put the truck in drive and apply the gas it starts going normally in first gear, then shifts to second, but when it shifts into third gear it looses power. when I say that, it goes into third gear and just revs. it wont speed up and has no torque. the torque is there when in first and second but not third. other then that I'm not sure what other info is needed. Thank You for your time.

 

sounds like the 3rd gear clutch pack is burnt up or the apply servo/motor is bad.....sounds like a trip to a GOOD tranny shop is needed