I have a 2010 GMC Sierra 1500, 44Kmiles, and the last few days I start to notice that on the highway, the tach will slip around between 2 and 4K rpm's when I accellerate.
I use the truck as my daily 50 mile commute to work, regualr oil changes, and moderate weekend towing (it has the tow package) for a trailer that holds 3 quads.
This morning, on my way in, I messed around with driving in tow mode, adn it seems the issue might go away when I do this, but probably coincidence.
Anyways, could my tranny be going already?
JJ in Pittsburgh
Are you planning on taking your Sierra to your local GMC dealership to have this issue diagnosed?
Evan, GM Customer Service
10yr 100,000mi warrenty should cover your issue!