Could be the mode door actuator. For more info visit our enthusiasts forum at www.trailvoy.com
My first stop would be the dealership. If you do not want to do that you could go to chevy.com to check out the Chevy Suburban. They would have all the info you need to make your decision.
Mostly, inability of it to continue to run. Please give us a bit more info on the circumstances involved.
Your owners manual will have all the info you need to do that.
What period of time? Did not exist late 1960's-now.
See the link to get that info. Hope This Helps.
Need to know the year, model and engine info.
background info
You haven't asked about a particular dealership. Virtually all Automobile dealers are Limited Liability Companies and the ownership and licencing info is available through your local government and town.
Where is the humming located front, rear? Could be a vaccuum leak if high pitched, wheel bearings, improper brake installation. More info needed.
Drive to the dealership and give the service dept. the VIN number and they will dispurse the info for free......
The vehicle year, model and engine info needed.