2008 Sierra codes P0751, 756, 761, 731, 877

[kwikwater]

I had the dealer flush and change all fluids @ 111,000 miles. Soon after I started having trouble with the tranny. 2008 GMC Sierra Duramax, 6 spd. I've kept clearing the codes and driving, but they're getting more frequent. Since most of these come back to solenoids & pressure switches, I think they stirred up the gunk and didn't get it all flushed out. The dealer, of course, denies it!! Any thoughts? Have the tranny flushed again by another shop?

 

[wjburken]

I had the dealer flush and change all fluids @ 111,000 miles. Soon after I started having trouble with the tranny. 2008 GMC Sierra Duramax, 6 spd. I've kept clearing the codes and driving, but they're getting more frequent. Since most of these come back to solenoids & pressure switches, I think they stirred up the gunk and didn't get it all flushed out. The dealer, of course, denies it!! Any thoughts? Have the tranny flushed again by another shop?

I’m guessing they didn’t drop the pan, clean it out and replace the filter first? Not sure that’s typical protocol, but it’s what I’ve asked them to do before.