I have a 2010 GMC Yukon Denali 2WD with the 6L80e with 100k miles. As recommended by the manual I changed the fluid and filter with all ACDelco parts and ACDelco VI full synthetic by dropping the pan, then refilled some and disconnected the oil cooler line and flowed and replaced the rest of the fluid in very small and short increments until the fluid was cherry red. Fluid was dark red but didn’t look to bad and no major burn smell. It’s currently 30 – 40 degrees F outside here and I can’t get the trans warm enough for a hot check. Max temp has been 130 degrees F. At cold fill it’s at the proper level. Now I’m having flair or slip between 2nd and 3rd. And a downshift flair from 4th to 3rd at low operational temperatures. Any advice?
Need one
I have a 2010 GMC Yukon Denali 2WD with the 6L80e with 100k miles. As recommended by the manual I changed the fluid and filter with all ACDelco parts and ACDelco VI full synthetic by dropping the pan, then refilled some and disconnected the oil cooler line and flowed and replaced the rest of the fluid in very small and short increments until the fluid was cherry red. Fluid was dark red but didn’t look to bad and no major burn smell. It’s currently 30 – 40 degrees F outside here and I can’t get the trans warm enough for a hot check. Max temp has been 130 degrees F. At cold fill it’s at the proper level. Now I’m having flair or slip between 2nd and 3rd. And a downshift flair from 4th to 3rd at low operational temperatures. Any advice?