Q&A

The gear oil in the rear end needs to be replaced. My truck started shuddering around 48k and i did a little research to find others with the same problem. Clutches in QS rear end are tough on the oil and begin to gum up btwn 36 to50k ( one third to half what the manual says it will, but thats another story) and it will need to be changed way sooner than the recommended service intravals.
part number 12378557 oil from dealer is the only thing you should put in it. You do not want anything else or the whole shooting match may go boom!

Replace oil and go to a parking lot and do about 50 figure eights in forward and reverse and it should go away completely in about 200 miles!

This does not sound like a quadrasteer problem!!!
I had the same issue with a 2002 Tahoe, it is the G80 locking rear differential that causes this. Chances are a fluid change will correct this problem!

 Rookie

Had this problem, read quite a few forms and it all pointed to the rear diff oil needed changing. Did this and all is well. mfg recommend, I think every 15K but people in the form said about every 50k will work. Special oil, make sure it is the right type or you could ruin your rear end