My '02 GMC Sierra, 4wd, 5.3L, automatic, 167K miles, has started making some whining noises from the drive train and don't think it is tire noise as it has Michelin LTX radials. Can't determine if it is transmission, rear end, differential or wheel bearing. Does anyone know of a mechanic around the Concord/Kannapolis area, or within about 40 miles, that they trust? I hate to take it to the dealership as they would tell me that it needs probably $20K worth of work.