GMFS founding member
hi, n00b here. i posted this over at putc but i figure you guys know what you're talking about as well. anyhow, i see there's a TSB for this under the 2003 sierra 1500 on alldata, but nothing for 2004 yet. i didn't sign up with them yet so i can't read the TSB, but can anyone describe what causes the problem? it makes a bad moaning/whining noise under accelleration when in 4hi or 4atuo, i noticed it today when driving on packed snow. it's going to the dealer monday, but i'd like to know exactly what is going on. tia.