Have a 96 GMC 4x4 Ext Cab with rear drums. Truck is used primarily on the weekends for hauling and towing. Drivers side rear brake is making an awful noise when turning (Especially Left) or backing up. When running on straight away I don't hear any noise and I can't feel any drag. Pulled the drum and there is plenty left on the shoes. I noticed 2 things. Shoes have a slight glaze mark about 3/8 from the inside. The Drum has the beginning of a groove starting in about the same place but the shoes don't have a ridge like I would expct to see. Could something in the rearend be causing this. Not really sure where to start toruble shooting.
Don't want to just buy new shoes and drum if there is another issue that needs to be addressed. Any help would be approciated

 

check the park brake cable for partially being engaged, common problem with 80-90 vintage GM product.

 

Checked Parking brake before pulling the drum. Wasn't enganged at all. Mechanic friend seems to think it is the axle bearing. Is there a way to check this??

 

Run the vehicle while safely elevated (on stands) w/ tire removed. Should hear noise if bearing is failing. Best way is to disassemble and visably inspect outer bearing.
Depending on which axle you have, you may need to remove differential cover and remove the axle shaft retainer clip first, inorder to slide the shaft out of the housing. good luck, let us know the outcome.