The more I read, I think the GM RPO code G80 is "loosely" used (by GM) to simply mean some form or fashion of a "traction enhanced" diff vs the typical "open" diff (non-traction enhanced). Some Gm vehicles use a "limited slip" diff (clutches) and others use a "locking" diff (mechanical). Limited slip and locking are just two different methods used in a "traction enhanced" diff. The G80 clutch type limited slip diff is always engaged 100% of the time and regardless of vehicle speed (except when one axle needs to slip a little as when turning on dry pavement). The G80 locking diff is dis-engaged (open diff) most of the time and engages only when the mechanism senses it needs to lock (one wheel spinning +/-100 rpm faster than the other and vehicle speed is below +/-20 mph.....above +/-20 mph, no lock-up). The limited slip G80 is intended a little more toward street/pavement enhanced traction while the locking G80 is intended a little more toward off-road enhanced traction. Again, both types of G80's are traction enhanced diffs......just accomplished differently.
