Chevrolet Traverses and their bretheren from 2009-2011 with the wearing out timing chains are pretty bad if the troublesome timing chains have to be replaced. I gather GM technicians loathe those jobs, because the engine has to come out. That might not be too bad if you could pull the engine with a hoist. Nope. The whole front end has to be dropped out. Propeller shaft, brake lines, steering shaft, air conditioning lines, transmission cooler lines, struts, all have to be disconnected in addition to the usual stuff you would have to disconnect from the engine. Then when it all goes back together, brakes have to be bled, air conditioning has to be recharged, and it needs a front end alignment.