I have a 86 c10 suburban ive had it a month and ive been hearing a crunching noise coming from rearend. took cover off to find that spider gears are junk previous owner had told me that they were bad also. So my options are replace spider gears, replace carrier with a posi, rebuild entire axle with a posi or find an axle at a junk yard that has a posi. Also this is a 10 bolt and i believe its been replaced cause rpo in glove box says its a locking rear end where as i have spider gears. My plan is to keep truck for long time and rebuild it as i go.